TScan Therapeutics, Inc. 10-K

Item 1. Business Overview We are a clinical-stage biopharmaceutical company focused on developing a robust pipeline of T cell receptor (TCR)-engineered T cell, or TCR-T, therapies for the treatment of patients with cancer. Our approach is based on the central premise that we can learn from patients who are winning their fight against cancer to treat those who are not. Over the past several years, we have built our ImmunoBank, a repository of therapeutic TCRs that recognize diverse targets and are associated with multiple human leukocyte antigen, or HLA, types. These TCRs are then used to manufacture enhanced TCR-T therapies to treat a broad population of patients with both heme and solid tumor malignancies. Every TCR in our ImmunoBank has come from our proprietary platform technologies, and we are continuing to expand our ImmunoBank. Using TargetScan, we analyze the T cells of cancer patients with exceptional responses to immunotherapy to discover how the immune system naturally recognizes and eliminates tumor cells in these patients. This allows us to precisely identify the targets of TCRs that are driving these exceptional responses. We then use these anti-cancer TCRs to treat patients by genetically engineering T cells to recognize and eliminate their cancer. In addition to discovering TCRs against novel targets, we are using our ReceptorScan technology to identify high affinity naturally occurring TCRs for known targets. Once we identify therapeutic candidates using these technologies, we reduce the safety risk of clinical development by comprehensively screening these TCRs against the human proteome using SafetyScan to identify potential off-target interactions. We then eliminate any TCR-T candidates that cross-react with proteins expressed at high levels in normal tissues. Our in-house good manufacturing practices, or GMP, T-cell engineering platform, which we refer to as T-Integrate, enables the rapid, cost-effective, and consistent manufacturing of TCR-Ts. Our TCR-T candidates are manufactured using a non-viral transposon/transposase system. This system is highly reproducible and can be routinely applied to new TCR-T candidates in a cost-effective manner without the need for extensive process development. The larger cargo capacity of our non-viral vector delivery system allows us to include additional T cell enhancements in our product candidates. In both our heme and solid tumor programs, we are introducing the gene for CD8α/β along with the TCR gene, which enables us to engineer both cytotoxic and helper T cells. We believe this enhancement has the potential to improve responses to TCR-T therapy in the clinic compared to engineering cytotoxic T cells alone. In our solid tumor program, we are also adding a dominant-negative (DN) form of TGFβRII to our T cells, which enables them to proliferate despite the presence of TGFβ in the hostile tumor microenvironment. This has the potential to enhance T cell persistence. Our GMP facility has the estimated capacity to manufacture clinical trial materials for up to 250 TCR-T components per year, sufficient to support all of our programs through Phase 2 clinical development. We are advancing a robust pipeline of TCR-T candidates for the treatment of patients with hematologic malignancies and solid tumors. Our lead product candidates, TSC-100 and TSC-101, are in development for the treatment of patients with hematologic malignancies to eliminate residual disease and prevent relapse following allogeneic hematopoietic cell transplantation (HCT). TSC-100 and TSC-101 target the antigens HA-1 and HA-2, respectively, which are well-recognized TCR targets that were first identified in patients with exceptional responses to HCT-associated immunotherapy. We have initiated a multi-arm Phase 1 "umbrella" clinical study of TSC-100 and TSC-101 with over ten clinical sites activated, and we plan to add more sites in 2024. In addition, we are developing multiple TCR-T candidates for the treatment of solid tumors. One of the challenges of treating solid tumors is that they are heterogeneous - not every tumor cell expresses a given target and some tumor cells lose half their HLA genes. To address this challenge, we are developing what we refer to as multiplexed TCR-T therapy - treating a patient with more than one TCR-T candidate at a time. We are designing these multiplexed therapies to be a simultaneous administration of up to three highly active TCR-T therapy candidates, selected from our ImmunoBank, that are customized for each patient based on which targets are expressed in their tumors and which HLA genes are still intact. We continue to prioritize expanding the ImmunoBank with TCRs for multiple targets and multiple HLA types for each target. We have now advanced six TCR-T therapy candidates into Phase 1 development for solid tumors: TSC-203-A0201 (PRAME, HLA-A*02:01); TSC-200-A0201 (HPV16, HLA-A*02:01); TSC-201-B0702 (MAGE-C2, HLA-B*07:02); TSC-204-A0201 (MAGE-A1, HLA-A*02:01); TSC-204-C0702 (MAGE-A1, HLA-C*07:02); and TSC-204-A0101 (MAGE-A1, HLA-A*01:01). In addition to clearing these six solid-tumor investigational new drug (IND) applications, the FDA has cleared our IND application for T-Plex, enabling us to treat patients with multiplexed TCR-T therapy. We plan to further expand the ImmunoBank in 2024 by filing IND applications for additional TCR-Ts. T cells are an essential component of the adaptive immune system and provide protection against cancer, infection, and autoimmune disorders. Multiple approaches have been and are continuing to be explored to develop effective T cell-based therapies for the treatment of cancer, including checkpoint inhibitor therapy, tumor infiltrating lymphocyte, or TIL, therapy, and chimeric antigen receptor (CAR) T cell, or CAR-T, therapy. The success of checkpoint inhibitor and TIL therapy depends on the specific T-cells present in the patient. If their T-cells do not have appropriate anti-cancer specificities, the therapy is unlikely to be effective. In addition, TIL therapy has, to date, shown limited applicability for the treatment of hematologic malignancies. In contrast, CAR-T therapy has proven effective in certain hematological malignancies of lymphoid origin but has not yet shown efficacy or safety in myeloid malignancies or solid tumors. To address a broader patient population, we believe additional T cell-based approaches are needed that more closely mimic the way the immune system recognizes and fights cancer. 5 Table of Contents The successful development of TCR-Ts has three key prerequisites: (i) an effective anti-cancer TCR; (ii) knowledge of the precise peptide antigen that is recognized by the TCR; and (iii) confirmation that the TCR does not recognize problematic off-targets. We believe our approach provides us with the following key advantages: • Our TCR-Ts are based on highly active TCRs that are clinically relevant. Many other approaches to T cell therapy rely on specifically expanding T cells that are already present in the patient. Our platform analyzes anti-cancer T cells from a broad set of individuals, including patients responding to immunotherapy as well as healthy donors, to find the most active and clinically relevant TCRs against each target. We believe that we can develop TCR-Ts for a wide range of patients, including those who do not have T cells that efficiently recognize their cancers. • Our TCR-Ts are designed to be used in combination with each other. We have built the ImmunoBank of TCRs to allow for multiplexed TCR-T, which has the potential to address the heterogeneous nature of solid tumors and prevent resistance developing due to target or HLA loss. We continue to expand the ImmunoBank with TCRs for multiple targets as well as multiple common HLA types for each target, thus helping us overcome the key solid tumor resistance mechanisms of target loss and HLA loss. • Our approach is expandable. The ImmunoBank has the flexibility to be used with new and optimized methods of T cell engineering that we may develop over time. We are currently employing the validated approach of patient-specific ex vivo engineering, but as the field evolves, our TCRs may be transitioned to " off-the-shelf" methods, including allogeneic T cells or in vivo engineering. As we expand the ImmunoBank to include TCRs across additional targets and HLA types, we believe we will increase the eligible patient population for our clinical trials, which will allow for rapid and efficient clinical trial enrollment with fewer screen failures. Our proprietary platform is designed to: (i) discover anti-cancer TCRs from patients with exceptional responses to immunotherapy; (ii) determine novel targets of clinically relevant TCRs; (iii) discover novel TCRs that recognize clinically validated targets; (iv) identify off-target interactions of TCRs to eliminate candidates that could potentially pose a safety risk; and (v) manufacture TCR-Ts efficiently and consistently without the use of viral vectors using our T-Integrate technology. The central elements of our platform that we believe differentiate us from other cell therapy companies are TargetScan, ReceptorScan, SafetyScan, the ImmunoBank, and T-Integrate. TargetScan. At the core of our proprietary platform is TargetScan, which enables us to identify natural targets of TCRs using an unbiased, genome-wide, high-throughput screen. We have developed this technology to be extremely versatile and applicable across multiple therapeutic areas, including cancer, autoimmune disorders, and infectious diseases. It can be applied to virtually any TCR that plays a role in the cause or prevention of disease. Using TargetScan, we have identified approximately 200 novel antigens as targets of tumor infiltrating T cells from patients who are actively responding to immunotherapy. We believe this provides us with a competitive advantage, because not only are we among the first to identify these targets as tumor-specific antigens, but we have also already identified 6 Table of Contents highly active TCRs that recognize these targets. Two of our pipeline programs emerged from TargetScan: TSC-201-B0702 (MAGE-C2, HLA-B*07:02) and TSC-204-C0702 (MAGE-A1, HLA-C*07:02), the latter of which was featured in the peer-reviewed journal Cell in 2022. ReceptorScan. To further expand our ability to discover and develop therapeutic TCRs, we have developed our proprietary ReceptorScan technology to enable us to identify and clone highly active TCRs that recognize known or clinically validated targets. We co-culture hundreds of millions of CD8+ T cells from either healthy donors or cancer patients with dendritic cells, also referred to as antigen-presenting cells, that display the target antigen of interest to the T cells. T cells that recognize the target of interest proliferate and are subsequently isolated based on their ability to recognize a fluorescently labeled version of the target. We then use single cell sequencing to identify the specific TCR sequences that recognize the target. Our novel technologies allow us to gene-synthesize hundreds of TCRs simultaneously and to rapidly sort through hundreds of target-specific TCRs in a single high-throughput screen to identify the most active clones. Using ReceptorScan, we have identified our two lead TCR-T candidates, TSC-100 targeting HA-1 and TSC-101 targeting HA-2, as well as several other pipeline programs, including TSC-203-A0201 (PRAME, HLA-A*02:01) and TSC-200-A0201 (HPV16, HLA-A*02:01). SafetyScan . SafetyScan is designed to identify potential off-target interactions of a given TCR and eliminate those TCR candidates that cross-react with proteins expressed at high levels in normal tissue. We believe this will allow us to reduce the risk and enhance the potential safety profile of our TCR-T candidates early in development before we initiate clinical trials. ImmunoBank. We are expanding the ImmunoBank, our diverse repository of therapeutic TCRs, to allow for multiplexed TCR-T therapy, which has the potential to address the heterogeneous nature of solid tumors and to prevent resistance developing due to loss of a single HLA haplotype. We believe this approach may allow us to overcome the limitations and challenges of TCR-T development to date. We continue to prioritize expanding the ImmunoBank with TCRs for multiple targets as well as multiple HLA types for each target, thus helping us overcome the key solid tumor resistance mechanisms of target loss and HLA loss. Finally, we are expanding the ImmunoBank to have the flexibility to be used with new and optimized methods of T cell engineering that we may develop over time. We have built the ImmunoBank to be compatible with autologous, allogeneic, and in vivo engineering technologies in order to potentially transition to generating off-the-shelf products for direct, customized administration to patients. T-Integrate. Manufacturing cell therapies is highly complex, and associated challenges have led to significant delays or failures in the development of many cell therapies. To enable the rapid, cost-effective, and consistent manufacturing of TCR-Ts, we have developed a non-viral vector delivery system that we refer to as T-Integrate. Our TCR-T candidates are manufactured using a transposon/transposase system, in which the DNA encoding the TCR is manufactured as a Nanoplasmid ™ , a non-viral vector. The Nanoplasmid, together with an mRNA sequence encoding a transposase enzyme, is introduced into the T cell by electroporation. After the T cell translates the mRNA into protein, the transposase enzyme inserts the TCR sequence from the Nanoplasmid, as well as any enhancements such as CD8 a / b and DN-TGF b RII, into the genome of the T cell. This system is highly reproducible, as the only required components are a Nanoplasmid, which is different for each TCR product, and an mRNA, which is constant for all TCR products. Unlike lentivirus, both components are routinely manufactured in a cost-effective manner without the need for extensive process development. We have completed the construction and qualification of a 7,000 square-foot state-of-the-art GMP manufacturing facility to manufacture all necessary Phase 1 and 2 supply for our TCR-Ts. We expect that this facility will provide sufficient production capacity to supply product for all planned Phase 1 and 2 clinical studies for the hematologic malignancies and solid tumor programs. We believe our manufacturing platform will enable us to efficiently develop and manufacture many different TCR-Ts, allowing us to deliver customized multiplexed therapy to patients with cancer. We have successfully manufactured TSC-100 and TSC-101 and have dosed patients in our hematological malignancies program. The FDA has additionally cleared seven IND applications for our solid tumor program, including our primary IND application T-Plex, which supports the use of multiple TCR-Ts to create customized multiplexed TCR-T therapy, as well as IND applications for TSC-200-A0201 (HPV16, HLA-A*02:01), TSC-201-B0702 (MAGE-C2, HLA-B*07:02), TSC-203-A0201 (PRAME, HLA-A*02:01), TSC-204-A0201 (MAGE-A1, HLA-A*02:01), TSC-204-C0702 (MAGE-A1, HLA-C*07:02), and TSC-204-A0101 (MAGE-A1, HLA-A*01:01), in our view further validating our manufacturing capabilities. 7 Table of Contents Our Pipeline We are expanding the ImmunoBank with the goal of delivering customized multiplexed TCR-T therapy to a wide range of patients with cancer. In addition, we are applying our platform to identify targets and TCRs in therapeutic areas outside of oncology, such as autoimmune disorders and infectious disease, through strategic partnerships. Our current proprietary pipeline is summarized in the figure below. In addition to our proprietary pipeline programs noted above, we have also entered into collaborations with strategic partners for applications of our platform technologies. We have a collaboration with Amgen Inc., or Amgen, to identify the antigens recognized by T cells in patients with Crohn's disease. Amgen will evaluate a variety of modalities to create therapeutic candidates based on targets discovered by TScan and will retain all global development and commercial rights. With our differentiated platform as the foundation, we are building a three-pillar research and development strategy to create transformational TCR-Ts for patients. 1. Our Hematologic Malignancies Program. We are developing TCR-T therapies to treat patients with heme malignancies, including acute myeloid leukemia, or AML, myelodysplastic syndromes, or MDS, and acute lymphocytic leukemia, or ALL, who are undergoing allogeneic HCT. In the first phase of our clinical development strategy, we are initially focusing on clinically validated cancer targets that have been discovered in patients with exceptional responses to HCT-associated immunotherapy, including HA-1 and HA-2. We are currently enrolling patients in a multi-arm Phase 1 "umbrella" clinical study with over ten clinical sites activated and additional sites planned to be added in 2024. The study protocol allows us to conduct clinical trials of TSC-100 and TSC-101 in parallel, with patients enrolled in treatment arms based on their genotype. Patients who are positive for the target antigen, HA-1 or HA-2, as well as the HLA-A*02:01 allele, which is the HLA type required to display HA-1 and HA-2 on the cell surface for recognition by a T cell, are eligible for enrollment. Eligible patients require donors who are negative for either the target antigen or the HLA-A*02:01 allele. Through the development of our hematologic malignancies program, we have built a foundation of manufacturing, clinical, and regulatory capabilities, which we are applying to the development of our broader portfolio of TCR-T candidates for solid tumors. 2. Our Solid Tumor Program. We are developing a portfolio of autologous TCR-T candidates designed to be used in combination with each other to treat and eliminate solid tumors. Our TSC-20X series of product candidates are designed to elicit anti-tumor responses in patients by targeting cancer-specific antigens in their tumor cells. Our TCR-T candidates include: (i) well-recognized cancer targets that have demonstrated anti-tumor activity in clinical trials or novel targets that were identified by TargetScan from the T cells of patients responding to immunotherapy, and (ii) naturally occurring TCRs specific to a patient’s HLA type that recognize these cancer-specific targets. Such targets are not only commonly shared among patients with the same cancer type, but also frequently expressed in multiple solid tumor types, enabling clinical development across multiple 8 Table of Contents indications. Our first six product candidates include a combination of known targets, such as HPV16 for TSC-200, the previously undisclosed target of MAGE-A4 for TSC-202, PRAME for TSC-203, and MAGE-A1 for TSC-204, as well as a target that is a novel antigen for TCR-T therapy, MAGE-C2 for TSC-201. In addition to our six lead product candidates, we have identified approximately 200 novel antigens as targets of tumor infiltrating T cells from patients who are responding to immunotherapy using our TargetScan technology. We are in early stages of analyzing these additional novel antigens and plan to advance those that we believe have the best potential as a TCR-T product candidate into preclinical development. Our vision is to create and continuously expand the ImmunoBank to enable customized multiplexed TCR-T therapy for a wide range of solid tumor patients. Our initial solid tumor indications include non-small cell lung cancer, head & neck cancer, melanoma, ovarian cancer, cervical cancer, and anogenital cancers. For each patient with a solid tumor malignancy, we first analyze the patient's tumor to determine which targets are expressed at high levels and which HLA genes are still intact. We then access the ImmunoBank and select up to three TCRs that match their HLA type and address the most highly expressed targets in their tumor. We will use this set of TCRs to genetically reprogram their T cells to recognize these targets, and the resulting T cells will be infused back into the patient as a multiplexed TCR-T therapy. Enabled by the additional cargo capacity of our non-viral vector delivery system, we are also introducing enhancements to our product candidates to deepen tumor responses and prolong duration of response. By introducing the gene for CD8α/β along with the TCR gene, we are able to engineer both cytotoxic and helper T cells which we believe has the potential to improve responses to treatment with TCR-T therapy in the clinic compared to engineering cytotoxic T cells alone. We are also adding a DN-TGFβRII to T cells, which allows them to proliferate despite the presence of TGFβ in the hostile tumor microenvironment. This has the potential to enhance T cell persistence. 3. Strategic Partnerships and Collaborations. T cells play a fundamental role in many other therapeutic areas beyond cancer, such as autoimmune disorders and infectious diseases. We believe that our TargetScan technology is well suited to discover novel antigens for the development of therapeutics, diagnostics, and vaccines in these other therapeutic areas. We intend to opportunistically pursue collaborations with strategic partners for applications of our platform technologies outside our core focus of oncology. Our Strategy Our mission is to create life-changing TCR-T therapies for patients by unleashing the untapped potential of the human immune system. Our goal is to use our proprietary platform technologies for the identification of novel tumor-specific antigens and clinically active TCRs to become a leader in the development of engineered T cell therapies for the treatment of hematologic malignancies and solid tumors. Our strategy includes the following key elements: • Leverage our proprietary platform technologies to build the ImmunoBank of therapeutic TCRs to treat a wide range of tumor types . Our TargetScan technology enables us to identify novel antigens that are broadly expressed across multiple types of solid tumors. To ensure that the antigens identified are clinically relevant, we use TCRs from tumor samples of patients with exceptional responses to immunotherapy. Our platform allows us to assess the specificity and cytotoxicity of these TCRs to develop a portfolio of TCR-T candidates with therapeutic potential. As we continue to expand our screening technology, we believe we will be able to fill the ImmunoBank of therapeutic TCRs with the diversity required to treat many solid tumors using multiplexed therapy. We continue to prioritize expanding the ImmunoBank with TCRs for multiple targets as well as multiple common HLA types for each target, thus helping us to overcome the key solid tumor resistance mechanisms of target loss and HLA loss. • Advance our lead product candidates, TSC-100 and TSC-101, through clinical development. Our two lead programs, TSC-100 and TSC-101, are designed to target HA-1 and HA-2, respectively, both of which are antigens with clinically demonstrated anti-tumor effects in patients who naturally develop T cells specific to these targets. Using our ReceptorScan technology, we generated hundreds of highly active TCRs that recognize HA-1 and HA-2. We selected TSC-100 and TSC-101 based on their superior potency and lack of off-target effects. We are currently enrolling patients in a multi-arm Phase 1 clinical study of TSC-100 and TSC-101 with over ten clinical sites activated, with additional sites planned to be added in 2024. The study protocol allows us to conduct clinical trials of TSC-100 and TSC-101 in parallel, with patients enrolled in treatment arms based on their genotype. In addition, through our hematologic malignancies program, we have established a foundation of manufacturing, clinical and regulatory capabilities to support the development of our broad portfolio of TCR-Ts. • Apply experience from our hematologic malignancies program to efficiently develop our solid tumor program targeting both novel and previously identified antigens. We are initially developing our TSC-20X series of TCR-Ts against five selected target antigens that are frequently expressed across multiple solid tumor types. Our first six solid tumor TCR-T candidates include a combination of known targets, such as HPV16 for TSC-200, MAGE-A4 for TSC-202, PRAME for 9 Table of Contents TSC-203, and MAGE-A1 for TSC-204, as well as a target that is a novel antigen for TCR-T therapy, MAGE-C2 for TSC-201. We believe that the treatment of solid tumors will require a combination of several therapeutic TCRs, which we refer to as 'multiplexed therapy'. We plan to leverage the foundation built from our heme malignancies program to efficiently develop a robust portfolio of TCR-T candidates and expand the ImmunoBank to enable multiplexed TCR-T therapy for the treatment of solid tumors. • Maintain internal manufacturing capabilities based on our non-viral T-Integrate system. We believe that in-house manufacturing capabilities substantially facilitate the successful early development of cell therapies. For our TCR-T candidates, we have developed a non-viral gene delivery system, which we refer to as T-Integrate, based on transposons that are designed to enable cost-effective and consistent cell manufacturing with short development times. We have built an internal, fully operational GMP manufacturing facility that we expect will provide sufficient capacity to support our clinical programs in both heme malignancies and solid tumors through Phase 2 clinical trials. The additional cargo capacity of our non-viral vector delivery system allows us to add T cell enhancements to our product candidates. By introducing the gene for CD8α/β along with the TCR gene, we are able to engineer both cytotoxic and helper T cells, which we believe has the potential to improve responses to TCR-T therapy in the clinic compared to engineering cytotoxic T cells alone. We are also adding a DN-TGFβRII to T cells, which enables them to proliferate despite the presence of TGFβ in the hostile tumor microenvironment. This has the potential to enhance T cell persistence. With the FDA clearance of our IND applications for TSC-100, TSC-101, and our seven IND applications for our solid tumor program, including our primary IND application, T-Plex, we consider our approach to be validated. • Develop next generation T cell engineering capabilities . Our long-term vision is to develop off-the-shelf products, either through allogeneic T-cell engineering or in vivo engineering, and provide customized multiplexed TCR-T therapy to patients with a wide range of malignancies. Although our initial solid tumor programs are autologous, we are developing T cell engineering technologies and in-house manufacturing capabilities to transition our therapeutic TCRs to alternative modalities. • Opportunistically pursue strategic partnerships and collaborations to maximize the full potential of our platform . Our platform represents a powerful tool to identify targets and TCRs in therapeutic areas outside of oncology, such as autoimmune disorders and infectious diseases. We intend to seek strategic partners with proven clinical development and commercialization capabilities for certain targets and/or assets that do not overlap with our internal programs or our core focus. To date, we have a research collaboration and license agreement with Amgen to identify the antigens recognized by T cells in patients with Crohn’s disease. Under the terms of the agreement, TScan received a $30 million upfront payment and is eligible to earn success-based milestone payments of over $500 million, based upon the achievement of certain development and commercial milestones as well as tiered single-digit royalty payments on net sales of products development from the collaboration. Amgen will evaluate a variety of modalities to create therapeutics based on targets discovered by TScan and will retain all global development and commercial rights to such therapeutics. We have also expanded our target discovery capabilities to include both CD8+ and CD4+ T cell target discovery by engineering our platform to include class II antigen presentation. This capability allows for us to expand discovery efforts into T-cell mediated autoimmune disorders that have a strong Major Histocompatibility Complexes, or MHC, class II linkage. We intend to leverage this new capability to identify the pathogenic autoantigens driving T-cell mediated autoimmune disorders. Background on T Cell Therapies The human immune system constantly provides a natural and highly effective defense against cancer, which only forms when tumor cells find a way to evade the immune system. The treatment of cancer was revolutionized over a decade ago with the advent of immunotherapy – therapeutic approaches designed to re-enable or re-direct immune cells to recognize and fight cancer. Over the past 10 years, a suite of immuno-oncology drugs has been approved and adopted as part of routine clinical practice. Successes in immuno-oncology came initially from the approval of immune checkpoint inhibitors and more recently from the development of cellular therapies, such as CAR-T and TIL therapies. These therapies all harness the power of cytotoxic T cells in fighting both hematologic malignancies and solid tumors. Although these therapies have demonstrated compelling efficacy, they are only effective in a subset of patients. To address a broader patient population, we believe additional T cell-based approaches are needed that more closely mimic the way the immune system recognizes and fights cancer in patients who are responding to immunotherapy. Overview of T Cell Biology T cells are an essential component of the adaptive immune system and provide protection against cancer, infection, and autoimmune disorders. T cells are classically divided into two primary types of activating cells: helper T cells and cytotoxic T cells. Helper T cells, which express the CD4 co-receptor, function by providing signals to other immune cells for activation and recruitment. Cytotoxic T cells, which express the CD8 co-receptor, function by killing any cells in the human body that are expressing unnatural proteins, including proteins that are not expressed in normal tissue, proteins that arise from mutated genes, or proteins derived from 10 Table of Contents pathogens. By definition, tumor cells are abnormal and make a wide variety of unnatural proteins. T cells are activated and exert their helper or cytotoxic function when their TCRs recognize antigens displayed on the surface of malignant or infected cells. Virtually every cell in the body has a mechanism for displaying on its surface a sampling of every protein that is being made by the cell. This includes all normal proteins as well as aberrant proteins if the cell is cancerous or proteins from pathogens if the cell has been infected. Cellular proteins are broken down into short fragments, or peptides, by the proteasome, and these peptides are loaded into MHCs to be displayed on the outside of the cell. These peptide/MHC complexes are recognized by TCRs on cytotoxic CD8+ T cells, as shown in the graphic below. Because the TCR recognizes both the peptide and the MHC, a TCR only functions correctly when both the peptide and the correct MHC are present. TCRs on Cytotoxic CD8+ T Cells Recognize the Peptide/MHC Complexes of Tumor Cells MHC proteins, which present different peptides to the human immune system, are highly variable among people. An individual’s MHC proteins are determined by their HLA type. Although there are many different HLA types, some are quite common. For example, 42% of individuals in the U.S. are positive for the HLA-A*02:01 allele, or variant. TCRs are often referred to as “HLA-restricted” because they are only able to interact with specific HLA types. For this reason, TCR-Ts harness the specificity of the TCR-peptide-MHC interaction to selectively target tumor cells. Current Approaches to T Cell Therapy Multiple approaches are being explored to develop effective T cell-based therapies for the treatment of cancer. One approach is to isolate naturally occurring T cells from a patient’s tumor, referred to as TILs, expand and activate those cells ex vivo , and then return them to the patient via intravenous infusion. Although the targets of these T cells are not known, it is presumed that T cells isolated from a tumor are enriched in T cells directed against cancer cells. This approach, however, depends on the anti-cancer T cells present in the patient. If the patient’s TILs do not have appropriate anti-cancer specificities or if their anti-cancer TILs cannot be adequately expanded ex vivo , the therapy is unlikely to be effective. A different approach that has proven effective in certain hematological malignancies is to identify targets that are highly expressed on the surface of tumor cells, such as CD19. Antibody fragments that recognize these targets are used to create an artificial construct that links the antibody to key signaling elements required for T cell activation. The resulting CAR is incorporated genetically into a 11 Table of Contents patient’s T cells, thereby redirecting those cells to recognize and fight the patient’s cancer. Although CAR-T therapies have been highly effective in certain tumor types, leading to multiple approved products, the benefit of these therapies and the addressable cancer indications have been limited by several factors. First, it is likely that there is a relatively limited set of truly tumor-specific cell surface antigens. In general, most antigens expressed on the surface of tumor cells are also expressed on normal cells, resulting in therapies that, even if effective, have a narrow therapeutic window and are vulnerable to potentially life-threatening toxicities. Second, CAR-T cells rely on antibody fragments that recognize cell-surface proteins, precluding intracellular proteins as potential targets. Third, CAR-T therapies generally do not efficiently penetrate solid tumors, which to date has limited their applicability to hematologic malignancies. In contrast to CAR-T therapies, naturally occurring TCRs offer two important benefits compared to antibody-containing artificial receptors. First, TCRs are the natural receptors used by the T cell to recognize foreign antigens. As such, they are optimized to stimulate the T cell appropriately when they engage their targets on a tumor cell. An appropriately stimulated T cell will not only kill the tumor cell, but also produce cytokines that stimulate other immune cells and make copies of itself, or proliferate, to further augment the immune response. Balancing all the cellular responses of a T cell is something that has been finely tuned over millions of years of evolution and is best mediated by naturally occurring TCRs, rather than by artificial constructs. Second, TCRs can recognize a much broader set of antigens, including peptides derived from both cell surface and intracellular proteins, whereas CARs are restricted to recognizing only cell surface proteins. MHC-I peptides are predominantly derived from intracellular proteins rather than extracellular proteins, which dramatically increases the universe of potential cancer-specific antigens that can be recognized by TCRs compared to CARs. We believe TCR-T therapy combines the benefits of TIL and CAR-T therapies while uniquely addressing their key limitations, as shown below. Reprogramming T cells with proven, highly effective TCRs has the potential to comprehensively treat all cancer patients The development of TCR-Ts requires three key prerequisites: (i) an effective anti-cancer TCR; (ii) knowledge of the precise peptide antigen that is recognized by the TCR; and (iii) confirmation that the TCR does not recognize problematic off-targets. Each of these prerequisites is technically challenging. Historically, targets of anti-cancer T cell clones were identified through a manual and labor-intensive process, and the identification of each target was often a multi-year project. As a result, only a few dozen targets have been identified to date and most clinical development efforts are focused on a short list of the most promising targets. Two key shortcomings in the TCR field remain: low response rates and limited duration of response. These are in part related to solid tumors being heterogenous, and to poor persistence of engineered T cells in patients. We believe we can overcome these known issues by adding enhancements to our product candidates, such as the addition of CD8α/β to improve persistence compared to CD8α alone. We are also co-introducing DN-TGFβRII, which is designed to overcome immunosuppression from TGFβ in the tumor microenvironment. 12 Table of Contents Our Approach Our approach is based on the central premise that we can learn from patients who are winning their fight against cancer in order to treat those who are not. Using our proprietary platform technologies, we are analyzing the T cells of cancer patients with exceptional responses to immunotherapy to discover clinically relevant targets and TCRs. We are expanding the ImmunoBank with the goal of delivering customized multiplexed TCR-T therapy to a wide range of patients with cancers. Learning When a patient responds to an immunotherapy drug such as an immune checkpoint inhibitor, their tumor shrinks because T cells in their tumor become activated and drive an anti-tumor cytotoxic response. The TCRs of their T cells recognize tumor-specific antigens on tumor cells and signal the T cell to kill the cancer cells. Our approach starts with isolating clinically active anti-cancer T cells from tumor samples of patients who are responding to immunotherapy agents. We then use our proprietary TargetScan technology to determine the precise targets being recognized by their TCRs. This provides us with a novel TCR/target pair that can be developed into a TCR-T candidate. The advantage of our approach is that when we identify a new target, we know the target is immunologically relevant – the human immune system has already used that target to recognize and fight cancer. Furthermore, we have already identified a TCR that recognizes the target and, importantly, is associated with a meaningful clinical response in a patient. To de-risk clinical development of the TCR, we use our SafetyScan technology to scan across every peptide sequence in the entire human proteome with the goal of ensuring that it does not have any problematic off-target effects. We then select TCRs that are highly active with no apparent problematic off-target effects to be added to the ImmunoBank. In addition to discovering novel TCR/target pairs, we are leveraging our proprietary ReceptorScan technology to identify highly active TCRs against previously identified and clinically validated targets. This approach was featured in the peer-reviewed journal Cell in 2022. Once we identify these highly active TCRs, we use our SafetyScan technology to reduce the risk that they exhibit problematic off-target effects, which de-risks their subsequent clinical development. The diagram below illustrates our proprietary discovery process where therapeutic TCR candidates are discovered using either TargetScan or ReceptorScan and those that we characterize as the best TCRs after screening with SafetyScan are added to the ImmunoBank. Our Proprietary Target and TCR Discovery Process Treating Our discovery process enables us to build and expand the ImmunoBank with what we believe represents the most active TCRs isolated from a large group of diverse patients who are responding to immunotherapy. We are developing TCR-Ts that use these clinically relevant TCRs to reprogram the T cells of patients who do not spontaneously generate effective anti-cancer T cells and thus do not respond to immunotherapy. Such patients will first have their tumors undergo HLA typing and testing for the presence of tumor-specific targets. Next, to manufacture engineered T cells, white blood cells will be obtained from either the patient or a healthy donor using a procedure called leukapheresis. We will then transport these white blood cells to our in-house manufacturing facility, where we isolate the T cells and genetically engineer them using TCR sequences from the ImmunoBank. We believe the continued expansion and diversification of the ImmunoBank will enable us to deliver customized multiplexed TCR-T therapies to more patients, where each 13 Table of Contents patient’s T cells are engineered with multiple TCRs that are matched to their specific tumor and HLA type. For example, if a patient’s tumor expresses high levels of a particular cancer target, their T cells will be reprogrammed with a TCR that recognizes that particular cancer target. The FDA's clearance of our T-Plex IND application for the simultaneous administration of different TCRs, as well as secondary IND applications for the first six TCRs in our solid tumor program, allows us to rapidly and efficiently expand the ImmunoBank and enables us to work toward our goal of bringing customized, multiplexed therapies to patients. Once the T cells are engineered with a combination of the most relevant TCRs, they will be transported back to the treatment facility and reintroduced into the patient by intravenous infusion. Following the infusion, the engineered T cells, which are designed to recognize multiple targets expressed by the patient’s tumor, will proliferate in vivo and mount an anti-cancer immune response. Our patient treatment and manufacturing process is summarized in the graphic below. Our Patient Treatment and Manufacturing Process Key Features of Our Approach We believe there are three key advantages to our approach: 14 Table of Contents • Our TCR-Ts are based on highly active TCRs that are clinically relevant. Many other approaches to T cell therapy rely on specifically expanding T cells that are already present in the patient. Our platform analyzes anti-cancer T cells from a wide variety of patients who are responding to immunotherapy in order to find the most active and clinically relevant TCRs against each target. We believe that we can develop TCR-Ts for a wide range of patients, including those who do not have T cells that efficiently recognize their cancers. • Our TCR-Ts are designed to be used in combination with each other. We are expanding the ImmunoBank of TCRs to allow for multiplexed TCR-T therapy, which has the potential to address the heterogeneous nature of solid tumors and to prevent resistance developing due to loss of a single target. We believe this approach may allow us to overcome the limitations and challenges of TCR-T development to date. We continue to prioritize expanding the ImmunoBank with TCRs for multiple targets as well as multiple common HLA types for each target, thus helping us to overcome the key solid tumor resistance mechanisms of target loss as well as HLA loss. As the ImmunoBank is populated with more TCRs, we expect that patient eligibility will expand, as will our target market opportunities. • Our approach is expandable. The ImmunoBank has the flexibility to be used with new and optimized methods of T cell engineering that we may develop over time. We have built the ImmunoBank to be compatible with both autologous and allogeneic engineering technologies in order to potentially transition to generating off-the-shelf, allogeneic T cells that have been pre-engineered with our TCRs for direct administration to patients. Our Platform Our proprietary platform is designed to: (i) discover anti-cancer TCRs from patients with exceptional responses to immunotherapy; (ii) determine novel targets of clinically relevant TCRs; (iii) discover novel TCRs that recognize clinically validated targets; (iv) identify off-target interactions of TCRs to eliminate candidates that could potentially pose a safety risk; (v) multiplex treatments through inclusion of clinically relevant targets with HLA type to customize treatments and (vi) manufacture TCR-Ts efficiently and consistently without the use of viral vectors using T-Integrate. The central elements of our platform that differentiate us from other cell therapy companies are our proprietary platform technologies: TargetScan, ReceptorScan, SafetyScan, the ImmunoBank and T-Integrate. TargetScan—Identification of Novel Targets of Clinically Active TCRs At the core of our proprietary platform is our TargetScan technology that enables us to identify the natural target of a TCR using an unbiased, genome-wide, high-throughput screen. We have developed this technology to be extremely versatile and applicable across multiple therapeutic areas, including cancer, autoimmune disorders, and infectious diseases. It can be applied to virtually any TCR that plays a role in the cause or prevention of disease. To identify the target of a clinically active TCR found in the T cells of a patient responding to immunotherapy, we mix T cells expressing that TCR with a genome-wide library of target cells where every cell in the library expresses a different protein fragment. In each target cell, the protein fragment is processed naturally by the proteasome or immunoproteasome and the resulting peptides are displayed on cell-surface MHC proteins. If a T cell recognizes the peptide-MHC complex on a target cell, it attempts to kill the target cell, thereby activating a proprietary fluorescent reporter in the target cell. By isolating fluorescent target cells and sequencing their 15 Table of Contents expression cassettes, TargetScan reveals the natural target(s) of the T cell, as shown below. This technology was published as a feature article in Cell in 2019. Overview of Our Proprietary TargetScan Technology Central to this technology is the library of protein fragments used for any given TargetScan screen. Our proprietary libraries comprise hundreds of thousands of specific sequences that collectively include most or all of the targets that a TCR could potentially recognize. For example, our current Oncology Target Discovery Library (version 3.0) comprises of 700,000 clones, each expressing a unique protein fragment. Collectively, these fragments span every human protein encoded in the human genome, along with all single nucleotide polymorphisms, or SNPs, which are single amino acid variations in naturally occurring proteins, observed at over 1% frequency in the human population. In addition, the library includes elements that are specific to cancer cells, which are particularly interesting to us as potential targets: common oncogenic driver mutations, cancer/testis antigens, human endogenous retroviruses, or HERVs, and a large collection of sequences that are not translated in normal tissue but frequently translated in human cancers. We constructed our libraries using a tiling pattern of overlapping fragments to provide complete and redundant coverage of every targeted sequence. Our Oncology Target Discovery Library allows us to precisely identify the novel targets recognized by TCRs from patients who are responding to immunotherapy. In addition, because the library comprehensively covers every non-mutated human protein sequence, we are also able to fully characterize all potential off-target interactions for any given TCR, which we believe will help us reduce the risk and enhance the potential safety profile of our TCR-T therapy candidates before we advance them to clinical development. Furthermore, we can use our screen for any HLA type, enabling target discovery across a wide range of patient demographics. SafetyScan—Elimination of Off-Target Activity SafetyScan is designed to identify potential off-target interactions of a TCR and eliminate those TCR candidates that cross-react with proteins expressed at high levels in critical organs. We believe this will allow us to reduce the risk and enhance the potential safety profile of our TCR-T candidates early in development before we initiate clinical trials. 16 Table of Contents The ability to identify problematic off-target interactions is critical as TCR-Ts engineered with TCRs that recognize off-targets expressed at high levels in critical organs could cause toxicities, thereby limiting their therapeutic potential. We use SafetyScan to screen affinity-enhanced versions of TCRs. Affinity enhancement is a process by which a naturally occurring TCR is mutated in order to generate a more potent therapeutic construct. One such affinity-enhanced TCR that we screened had previously entered clinical trials with a different sponsor, but human testing of the TCR was halted abruptly because two patients treated with T cells engineered to express this affinity-enhanced TCR died of acute cardiac failure within five days of T cell administration. Subsequent studies revealed that this TCR recognized an off-target derived from the muscle protein titin, which is abundantly expressed in cardiac tissue. When we screened this same affinity-enhanced TCR using our SafetyScan technology, we identified a variety of potential additional off-targets which were not seen in our screen of the natural TCR, including the protein titin. This experiment demonstrates why we believe that our SafetyScan technology provides a significant competitive advantage, because it enables us to rapidly and efficiently eliminate from our preclinical pipeline TCRs that are identified as recognizing potentially problematic off-targets. Importantly, this includes off-targets that may not be identified through standard bioinformatics or in- vitro tissue assays. We believe that SafetyScan thereby has the potential to enable us to decrease the risk of encountering unexpected toxicities in our clinical trials by providing a genome-wide understanding of off-target effects. Using our TargetScan technology, we have identified approximately 200 novel antigens as targets of tumor infiltrating T cells from patients who are responding to immunotherapy. We believe this provides us with a competitive advantage, because not only are we among the first to identify these targets as tumor-specific antigens, but we have also already identified highly active TCRs that recognize these targets. ReceptorScan identifies ultra-high affinity, naturally occurring TCRs with low risk of off-target effects T-Integrate—Genetic Engineering of T Cells Using Transposons Cell therapy manufacturing is highly complex, and associated challenges have led to significant delays or failures in the development of many cell therapies. To enable the rapid, cost-effective, and consistent manufacturing for a variety of selected TCRs, we have developed a non-viral vector delivery system that we refer to as T-Integrate. Our manufacturing platform enables us to introduce any of the TCRs from the ImmunoBank, along with additional genetic elements such as CD8 that further augment T cell function, into the genomes of patient- or donor-derived T cells. Genetically engineering a T cell requires two steps: (1) delivering DNA encoding the TCR into the nucleus of a T cell and (2) integrating that DNA into the genome of the T cell. These two steps are often accomplished through the use of retroviral vectors, such as lentivirus, by packaging RNA encoding the TCR into lentiviral particles, which are then used to infect T cells. Although effective, manufacturing lentiviral particles is time-consuming, costly, and often highly variable. In addition, each new TCR requires extensive process development, as the TCR sequence affects the efficiency with which it is packaged into the lentivirus. 17 Table of Contents As a more efficient and reproducible alternative to lentivirus, we have developed T-Integrate to genetically engineer T cells using a transposon/transposase system, as shown in the graphic below. In this system, DNA encoding the TCR is manufactured as a Nanoplasmid ™ and enables DNA delivery using a smaller plasmid footprint. The Nanoplasmid, together with an mRNA sequence encoding a transposase enzyme, is introduced into the T cell by electroporation. After the T cell translates the mRNA into protein, the transposase enzyme inserts the TCR sequence from the Nanoplasmid into the genome of the T cell. This system is highly reproducible, as the only required components are a Nanoplasmid, which is different for each TCR product, and an mRNA, which is constant for all TCR products. Unlike lentivirus, both of these components are routinely manufactured in a cost-effective manner without the need for extensive process development. We believe our manufacturing platform will enable us to efficiently develop and manufacture many different TCR-Ts, allowing us to deliver customized multiplexed therapy to patients with cancer. We have successfully manufactured TSC-100 and TSC-101 and dosed patients in our hematologic malignancies program. The FDA has cleared seven IND applications for our solid tumor program, including our primary IND application, T-Plex, which supports the simultaneous administration of multiple TCRs to create customized multiplexed TCR-T candidates, as well as IND applications for TSC-200-A0201 (HPV16, HLA-A*02:01), TSC-201-B0702 (MAGE-C2, HLA-B*07:02), TSC-203-A0201 (PRAME, HLA-A*02:01), TSC-204-A0201 (MAGE-A1, HLA-A*02:01), TSC-204-C0702 (MAGE-A1, HLA-C*07:02), and TSC-204-A0101 (MAGE-A1, HLA-A*01:01). Our T-Integrate Manufacturing Platform Our transposon vector includes both the beta and alpha chains of the TCR under the control of a strong promoter. This is designed to ensure that high levels of the TCR are produced on the surface of the T cells and that the TCRs that are normally expressed in the patient’s or donor’s T cells, or the ‘endogenous’ TCRs, are suppressed. We have also introduced specific alterations in the constant region of the TCR to further augment its stability. In addition to the TCR, our transposon construct includes genes encoding the alpha and beta chains of the cell-surface protein CD8. CD8 forms a complex with the TCR and is necessary for the TCR to recognize its target on tumor cells. Including the CD8 co-receptor in our construct enables us to genetically reprogram both major types of T cells: cytotoxic T cells that naturally make their own CD8, and helper T cells that do not make CD8. Our final TCR-Ts are a mixture of both cytotoxic and helper T cells that have been reprogrammed to recognize and eliminate tumor cells expressing the relevant targets. We also included a short peptide tag at the beginning of CD8α in our construct. This tag does not interfere with the function of CD8α but provides a way to easily purify the engineered T cells during our manufacturing process. We are also enhancing our T cell therapies with the addition of DN-TGFβRII to overcome the immunosuppressive tumor microenvironment. An illustration of the construct of our TCR-Ts is shown below. 18 Table of Contents Construct of our TCR-Ts Another important advantage of T-Integrate, our manufacturing platform, is that its greater carrying capacity than the commonly used lentiviral approach enables us to introduce additional genes that augment T cell function along with the gene that encodes the TCR itself. As our programs advance, we intend to introduce additional elements to our products with the goal of further improving their performance in the solid tumor setting, including features designed to increase the penetration of our T cells into solid tumors, with the aim of keeping our T cells active for a longer time and rendering our T cells more impervious to the hostile tumor microenvironment. Our Hematologic Malignancies Program We are developing our hematologic malignancies program to treat patients with AML, MDS, or ALL who are undergoing allogeneic HCT. In the first phase of our clinical development strategy, we are initially focusing on well-recognized cancer targets that have been discovered in patients with exceptional responses to HCT-associated immunotherapy, including HA-1 and HA-2. Our program is based on the well-established observation that patients who are mismatched with their donors for minor histocompatibility antigens such as HA-1 or HA-2, and naturally mount a T cell response against those antigens, show significantly lower relapse rates following HCT. By developing TSC-100 and TSC-101, TScan aims to recreate this natural graft versus leukemia response to prevent relapse in patients undergoing HCT. Minor histocompatibility antigens like HA-1 and HA-2 are distinct from other cancer-associated antigens such as WT1 previously targeted by TCR-Ts in hematologic malignancies. As shown below, cancer-associated antigens like WT1 have low and heterogenous expression and were previously selected so that normal blood cells in the patient would be relatively spared. WT1-targeted TCR-Ts proved to have relatively poor efficacy in patients with AML, potentially due to the rapid emergence of resistant tumor cells that had lacked WT1 expression and thus escaped killing by engineered T cells. HA-1 and HA-2 in contrast have high and homogenous expression (see below), making it less likely for tumors cells to escape due to low antigen expression. While HA-1 and HA-2 are also expressed in normal blood cells, treating HA-1/HA-2 positive patients who receive stem cell transplantation from donors who are negative for HA-1/HA-2, ensures that the engineered T cells selectively eliminate all the patient’s blood cells, malignant, pre-malignant or normal, while sparing donor-derived normal blood cells. This strategy therefore enables high levels of anti-cancer efficacy with what we believe to be less risk of life-threatening toxicities to normal cells. 19 Table of Contents We are conducting clinical trials of our lead TCR-T candidates, TSC-100 and TSC-101, in parallel, with patients enrolled in treatment arms based on their genotype, as shown below. Patients who are positive for the target antigen, HA-1 or HA-2, as well as the HLA-A*02:01 allele, which is the HLA type required to display HA-1 and HA-2 on the cell surface for recognition by a T cell, will be eligible for enrollment. Furthermore, eligible patients will require donors who are negative for either the target antigen or the HLA-A*02:01 allele. Our Clinical Development Strategy for Multiple TCR-T Candidates Background on Hematologic Malignancies HCT has become the standard of care for many hematologic malignancies. When a patient with leukemia undergoes HCT, they start by receiving a conditioning regimen of high dose chemotherapy with or without radiation. This regimen is intended to kill both the patient’s leukemia cells as well as their native blood cells and blood cell precursors, including hematopoietic stem cells in their bone marrow. The patient then receives hematopoietic stem cells from an HLA-matched donor. The stem cells engraft in their bone marrow 20 Table of Contents and start to repopulate their body with new blood cells, which are now genetically identical to the donor. HCT has demonstrated the rare opportunity in cancer treatment to generate long-term remissions or cures. For example, patients with AML who receive HCT have a five-year post-transplant survival rate of up to 40%. Approximately 8,000 allogeneic HCT procedures are performed yearly in the U.S., primarily in patients with AML, MDS, or ALL. Approximately 7,500 allogeneic HCT procedures are performed yearly in the U.S. in patients with AML, MDS, or ALL. As a curative therapy for many hematologic malignancies, use of HCT has been steadily increasing over the last two decades, with increased use driven largely by increasing donor qualification, an increase in disease prevalence due to aging populations, and improved conditioning regimens permitting broader use in older and frailer patient segments. In addition, newer, more effective leukemia therapies continue to drive an increasing use of HCT in patients who previously failed to achieve proper remission prior to transplant. While the approval of CAR-T therapies has significantly impacted the treatment of B cell malignancies over the last decade, HCT in non-B cell malignancies is anticipated to remain the standard of care for patients. An example of the limitations associated with CAR-T therapy is the difficulty differentiating tumor from normal cells as seen with CD19-targeted CAR-T therapies. CD19 is a target highly expressed on the surface of tumor cells, as well as normal B cells, which are also eliminated by CD19 targeted CAR-T cells. While loss of B cells does not generally lead to serious complications, toxicity on other normal myeloid blood cell types such as neutrophils would cause a life-threatening complication called febrile neutropenia in which bacterial infections occur due to the loss of neutrophils. This is one reason why CAR-T therapies cannot be used in non-B cell hematologic malignancies such as myeloid leukemias and HCT remains the standard of care for those patients. However, despite the increasing use of HCT and the resulting clinical benefits or cures, approximately 40% of the patients who receive HCT relapse, at which point there are limited treatment options, and the prognosis is very poor. Clinical observations have shown that if the T cells of the donor recognize certain minor histocompatibility antigens, or miHAs, in the patient’s leukemia cells, such as proteins that have single amino acid differences between the patient and the donor, the T cells of the donor drive a specific graft vs. leukemia, or GvL, effect, whereby the engrafted donor T cells detect remaining leukemia as foreign and eliminate the remaining disease. As a result, the patient often experiences a long-term remission from their cancer, or even a complete cure. If the miHAs are also expressed in non-hematopoietic tissues, the patient may develop graft vs. host disease, or GvHD, but if the miHAs are only expressed in blood cells, a specific GvL effect is observed without an increase in GvHD. Our hematologic malignancies program is focused on targeting miHAs that are exclusively expressed in hematopoietic cells in order to induce the GvL effect while potentially mitigating the risk of GvHD. TSC-100 TSC-100 is an allogeneic, donor derived TCR-T candidate directed at eliminating all native blood cells, including residual cancer cells, in HA-1-positive and HLA-A*02:01-positive patients with hematologic malignancies who undergo HCT using a donor who is either HA-1-negative or HLA-A*02:01-negative. Using ReceptorScan, we screened over a hundred million CD8+ T cells and identified and assessed hundreds of highly active TCRs that recognize the HA-1 antigen. We selected TCR-100a based on its superior affinity, cytotoxic activity, and specificity compared to the others. TSC-100 is designed to elicit an anti-tumor response in patients by targeting HA-1, which is present on malignant and normal blood cells of HA-1-positive patients but not on any of the new, donor-derived blood cells they receive from a donor who is either HA-1-negative or HLA-A*02:01-negative. We believe that donor T cells specifically engineered to express TCR-100a will generate an anti-tumor effect in patients, leading to a reduction in relapse rates and an increase in long-term survival. HA-1 was one of the first miHAs to be discovered in a patient undergoing HCT. HA-1 is a peptide antigen derived from the protein ARHGAP45, which is an intracellular protein expressed at high levels in all blood cells but not in any other tissue. ARHGAP45 comes in two forms. In HA-1-positive individuals, the peptide has the sequence VL H DDLLEA and, if the individual has the HLA type A*02:01, the antigen is efficiently displayed on the surface of blood cells. In HA-1-negative individuals, the peptide has the sequence VL R DDLLEA, and the HA-1 antigen is not displayed. Approximately 60% of people have the VL H DDLLEA sequence and approximately 42% of people in the U.S. have the HLA type A*02:01, which means that approximately 25% of individuals in the U.S. are HA-1-positive with the specific HLA type required for antigen expression. Studies of patients receiving HCT have shown that in cases where the T cells of an HA-1-negative donor naturally develop a response to HA-1 in an HA-1-positive patient, the T cells mediate a specific GvL effect, and the patient often experiences a long-term remission. TSC-100 is based on this clinical observation and is designed to specifically cause this GvL effect in patients receiving HCT. We are developing TSC-100 as a treatment for patients with cancer who are HA-1-positive and have been deemed eligible for HCT. For each patient, a healthy donor who is HA-1-negative or HLA-A*02:01-negative will be identified. Hematopoietic stem cells isolated from that donor will be used as the source of transplant material. In parallel, T cells isolated from the same donor will be genetically engineered to recognize HA-1. Once engraftment of donor stem cells is established in the patient, TSC-100 will be infused into the patient with the goal of eliciting a highly specific anti-tumor effect. The engineered donor T cells are designed to recognize and 21 Table of Contents eliminate all of the patient’s native blood cells, including residual leukemia cells, which are HA-1-positive, thereby preventing relapse and potentially promoting complete cures. Because the patient’s new healthy blood cells are derived from the donor and are therefore either HA-1-negative or HLA-A*02:01-negative, we believe that TSC-100 should have minimal toxic side effects. A summary of the treatment paradigm for TSC-100 is illustrated below. TSC-100 Treatment Paradigm Because people inherit two copies of every chromosome, one from their mother and one from their father, everyone has two copies of the ARHGAP45 gene. HA-1-positive patients can therefore be either homozygous for HA-1 (+/+), with both genes encoding the HA-1-positive peptide (VL H DDLLEA), or heterozygous for HA-1 (+/-), with one gene encoding the HA-1-positive peptide and the other encoding the HA-1-negative peptide (VL R DDLLEA). To ensure that TSC-100 can effectively eliminate healthy blood cells and leukemia cells that are either homozygous HA-1-positive (+/+) or heterozygous HA-1-positive (+/-), we assessed the activity of TSC-100 against blood cells derived from a variety of healthy donors and patients with AML and ALL. In preclinical studies, TSC-100 eliminated both homozygous and heterozygous HA-1-positive healthy blood cells and leukemia cells. It is known in the cell therapy field that TCRs which exhibit off-target effects can potentially cause toxicity. To reduce the potential for TCR-100a to exhibit problematic off-target effects, we used SafetyScan to comprehensively scan for any other potential targets recognized by TCR-100a. In the screen, all three protein fragments in the library that contain the HA-1-positive peptide antigen were strongly enriched, and no significant off-target interactions were observed. In contrast, some of the other HA-1-specific TCRs identified by ReceptorScan did exhibit off-target effects, highlighting our ability to select candidates that we believe have favorable risk/benefit profiles. TSC-101 Like TSC-100, TSC-101 is an allogeneic, donor derived TCR-T candidate directed at eliminating residual cancer cells in HA-2-positive and HLA-A*02:01-positive patients with hematologic malignancies who undergo HCT using a donor who is either HA-2-negative or HLA-A*02:01-negative. HA-2, which is derived from the protein MYO1G, is another miHA that has been identified to be clinically relevant. In patients who naturally develop HA-2-specific T cells, a GvL effect has been observed and these patients experience long-term remissions. Using ReceptorScan, we have identified a highly active TCR, which we refer to as TCR-101a, that recognizes HA-2. Unlike HA-1, the HA-2 antigen is highly prevalent, with approximately 95% of individuals in the U.S. being HA-2-positive. However, as with HA-1, a specific HLA type, HLA-A*02:01, which is present in approximately 42% of individuals in the U.S., is required to display the HA-2 antigen on the cell surface for recognition by a T cell. As a result, approximately 40% of HCT patients 22 Table of Contents would be positive for both HA-2 and HLA-A*02:01 and therefore be eligible for treatment with TSC-101 using a donor who is negative for HLA-A*02:01, regardless of whether the donor is HA-2-positive or HA-2-negative. Such donors are straightforward to identify and should be available to most patients who undergo half-matched, or haploidentical, transplantation using family members as donors, as patients typically have between two and three potential haploidentical donors. Like TCR-100a, we used ReceptorScan to identify TCR-101a. We screened approximately 237 million CD8+ cells from five healthy HA-2 negative donors and identified approximately 1,302 natural TCRs that recognize HA-2. These were then narrowed down to 15 TCRs with the highest surface expression and greatest affinity for the HA-2 peptide. We further evaluated the top five TCRs for off-target cross-reactivity against the entire human proteome using SafetyScan, identifying TCR-101a as the most active TCR with the lowest off-target activity and cleanest cross-reactivity profile against 108 other HLA alleles. Finally, TSC-101, our TCR-T candidate which is T cells manufactured to express TCR-101a, was tested on a panel of normal cell types representing all vital organs and did not recognize any normal non-hematologic cell type. In contrast, TSC-101 demonstrated efficient cell killing of both normal and malignant primary hematologic samples confirming a high degree of selectivity for hematologic cells. The discovery of TCR-101a was presented at the 63 rd American Society of Hematology Annual Meeting and Exposition, in December 2021. Clinical Development Plan for Our Hematologic Malignancies Program Background on Types of HCT Patients with acute leukemias who undergo allogeneic HCT have heterogeneous outcomes that are primarily related to two main variables: (i) the intensity or doses of the conditioning regimen they receive prior to the stem cell infusion and (ii) the type of donor who provides the stem cells. High-intensity conditioning regimens are called myeloablative conditioning and are associated with higher mortality rates. They are therefore reserved for young and relatively fit patients. Lower-intensity regimens are called reduced-intensity conditioning, or RIC, and are better tolerated, but are associated with higher relapse rates. TSC-100 and TSC-101 are both designed to substantially reduce relapse rates, and we are enrolling patients who are eligible for RIC-based HCT with the goal of improving clinical outcomes for these patients. There are different types of donors who are eligible for allogeneic HCT procedures. Donors who are siblings of the patient and are perfectly matched for eight out of eight HLA alleles are considered the highest priority donor type for patients undergoing allogeneic HCT, but these types of donors are available for less than a third of patients. For most patients, the choice is between an unrelated donor who is perfectly matched for eight out of eight HLA alleles, referred to as a matched unrelated donor, or MUD, or a family member such as a sibling or child who has a half-match with the patient, referred to as a haploidentical donor, or haplo. Historically, haplo donor transplantation was associated with much higher GvHD than MUD transplants, but a recent treatment regimen that uses chemotherapy given three days after stem cell infusion called post-transplantation cyclophosphamide, or PTCy, specifically kills immune cells that cause GvHD. As a result, haplo transplants with PTCy have recently achieved equivalent outcomes as MUD transplants and are rapidly increasing in usage in the U.S. and worldwide. The use of haplos greatly expands the donor pool for patients undergoing HCT and provides patients with the optionality to choose donors who are mismatched on specific HLA types, such as A*02:01, as opposed to being mismatched on certain minor antigens, such as HA-1 or HA-2. We are developing TSC-100 and TSC-101 with a specific focus on patients undergoing haplo donor transplantation with donors who are negative for either the miHA or the specific HLA type. We believe the engineered donor T cells will recognize any residual leukemia cells, which are target-positive, in the patient and prevent relapse with the potential to promote complete cures. Because the patient’s new healthy blood cells are derived from the donor and are therefore either target-negative or not able to express the target, we believe TSC-100 and TSC-101 should have minimal toxic side effects. Phase 1 Clinical Trial The clinical studies for TSC-100 and TSC-101 are well underway, within a multi-arm, controlled, Phase 1, "umbrella" design clinical trial to investigate the safety and efficacy of TSC-100 and TSC-101 in patients with ALL, AML, and MDS, that are undergoing HCT following RIC. We are currently dose escalating both treatment arms and are currently treating patients at the third and final dose level. Our Phase 1 clinical trial is designed to include measurements of early surrogate markers of efficacy, such as donor chimerism, or the percentage of blood cells that are donor-derived, and whether patients continue to have detectable residual leukemia, referred to as minimal residual disease, or MRD, in their post-transplant bone marrow biopsy, both of which are predictors of relapse. As shown in the graphic below, we are also including a control arm, comprising patients who do not meet the HLA or miHA genetic criteria and are 23 Table of Contents treated with standard RIC haplo transplantation alone. Comparisons of both safety and efficacy outcomes with this control arm will potentially enable all patients treated with TSC-100 or TSC-101 to be included as part of the efficacy analysis for the initial Phase 1 trial prior to transitioning the program into a registrational Phase 2 trial towards a future biologics license application, or BLA, filing. Multi-Arm Phase 1 Clinical Trial Design Initial clinical data In February 2024 we reported updated results on the first 14 patients enrolled in our ongoing Phase 1 hematologic malignancies study, which we presented at the 2024 Tandem Meetings: Transplantation & Cellular Therapy Meetings of the American Society for Transplantation and Cellular Therapy (ASTCT ® ) and the Center for International Blood and Marrow Transplant Research (CIBMTR ® ). Eight patients were enrolled in the treatment arms, and six patients were enrolled in the control arm. A total of four patients were treated with TSC-100, one with T-ALL, two with AML, and one with MDS, and four patients were treated with TSC-101, one with TP53-mutated MDS, one with AML and two with B-ALL. In both the TSC-100 and TSC-101 treatment arms, all patients (8/8) achieved complete donor chimerism, associated with a favorable prognosis. One AML patient was MRD-positive following HCT, converted to MRD-negative following treatment with TSC-101, and maintained MRD-negative status, with the most recent measurement at day 180 post-transplant. The six control-arm patients, three with MDS and three with AML, were enrolled and received standard of care consisting of HCT alone. One TP53-mutated MDS control-arm patient evolved with MRD positivity and worsening mixed chimerism, ultimately experiencing disease relapse approximately six months after transplantation and unfortunately succumbed to the relapse approximately nine months after transplant. Additionally, one MDS patient in the control arm had a clinical relapse approximately five months after transplantation, and one MDS patient in the control arm developed worsening mixed chimerism that prompted early termination of immunosuppression resulting in complete donor chimerism. Two of the six patients in the control arm achieved complete donor chimerism following HCT. Anticipated timeline We have now successfully manufactured and dosed patients in both treatment arms of the Phase 1 clinical trial. Patients have been enrolled up to the third and final dose level in both treatment arms with no dose limiting toxicities thus far, suggesting that the third and final dose level will likely become the recommended Phase 2 dose. We expect to open expansion cohorts at this recommended Phase 2 dose level to further characterize safety and evaluate translational and efficacy endpoints in the third quarter of 2024. Additionally, we plan to complete enrollment and report one-year clinical and translational data on initial patients in 2024 and report two-year prevention of relapse data in 2025. Future market expansion opportunities If TSC-100 and TSC-101 demonstrate the ability to significantly reduce relapse rates after HCT, there could potentially be new opportunities to expand the curative potential of HCT combined with TSC products to greater numbers of patients. Currently, only about 7,500 patients with AML, MDS, or ALL undergo HCT per year in the U.S. out of approximately 35,000 patients diagnosed each year. There are two reasons for this relatively modest rate of transplant use. First, only patients who achieve a clinical complete remission (CR) are referred for HCT since the relapse rates of patients not in CR are considered too high to effectively use HCT. If HCT, combined with either TSC-100 or TSC-101, markedly reduces relapse rates, patients who do not achieve CR could possibly undergo HCT and 24 Table of Contents benefit from its curative potential. This market expansion would require a separate clinical trial. Second, while RIC has enabled many more elderly and frail patients to undergo transplantation, the chemotherapy and radiation doses used for conditioning are still high and considered too toxic for most patients over the age of 65 or those with underlying comorbidities. This is because the conditioning regimen of HCT is considered the primary modality for eliminating residual leukemia cells and reducing doses further would result in greater relapse rates. If, the relapse rates could be reduced by treatment with either TSC-100 or TSC-101 post HCT, however, a clinical trial could test the use of minimal intensity conditioning prior to HCT. If successful, this would further expand the curative potential of HCT combined with TSC-100 or TSC-101 therapy to older, frailer patients. A final market expansion opportunity could occur from the use of either TSC-100 or TSC-101 as a chemotherapy and radiation-free conditioning regimen for non-malignant diseases such as sickle cell anemia which are currently treated with HCT. Since chemotherapy and radiation are associated with the risk of long-term toxicities such as cancer, heart damage, lung damage and infertility, cellular therapies such as TSC-100 or TSC-101 could reduce those risks and increase the numbers of patients willing to undergo HCT for non-malignant diseases. Solid Tumor Program We are developing a portfolio of autologous TCR-T candidates designed to be used in combination with each other to treat and eliminate solid tumors. Our TSC-20X series of product candidates are designed to elicit an anti-tumor response in patients by targeting cancer-specific antigens in their tumor cells. Our TCR-T candidates include: (i) either well-recognized cancer targets that have demonstrated anti-tumor activity in clinical trials or novel targets that were identified by TargetScan from the T cells of patients responding to immunotherapy and (ii) naturally occurring TCRs specific to a patient’s HLA type that recognize these cancer-specific targets. Such targets are not only commonly shared among patients with the same cancer type, but also frequently expressed in multiple solid tumor types, enabling clinical development across multiple indications. Our six solid tumor TCR-T candidates include a combination of known targets, such as HPV16 for TSC-200, the previously undisclosed target MAGE-A4 for TSC-202, PRAME for TSC-203, and MAGE-A1 for TSC-204, as well as a novel TCR-T target that has not yet been tested in the clinic, MAGE-C2 for TSC-201. To date, we have received FDA clearance for seven INDs for the treatment of solid tumors. These include a primary IND for the entire solid tumor program, which we refer to as T-Plex, which supports the simultaneous use of multiple TCRs to create customized multiplexed TCR-T candidates based on target and HLA expression. The FDA has also cleared INDs for TSC-203-A0201 (PRAME, HLA-A*02:01); TSC-200-A0201 (HPV16, HLA-A*02:01); TSC-201-B0702 (MAGE-C2, HLA-B*07:02); TSC-204-A0201 (MAGE-A1, HLA-A*02:01); TSC-204-C0702 (MAGE-A1, HLA-C*07:02); and TSC-204-A0101 (MAGE-A1, HLA-A*01:01). We plan to further expand the ImmunoBank by filing INDs for additional TCRs throughout 2024. In addition to our lead solid tumor TCR-T programs, we have identified about 200 novel antigens as targets of tumor infiltrating T cells from patients who are responding to immunotherapy using our TargetScan technology. We are in early stages of analyzing these additional novel antigens and plan to advance those that we believe have the best potential as a TCR-T therapy candidate into preclinical development. We have built the ImmunoBank, a repository of highly active TCRs, to enable multiplexed TCR-T therapy. Our vision is to expand the ImmunoBank with TCRs that recognize diverse targets and are associated with multiple HLA types to provide a broad array of therapeutic options for patients with various types of solid tumors. For patients with a solid tumor malignancy, we plan to analyze their tumor to determine which targets are expressed at high levels in their cancer. We will then access the ImmunoBank and select up to three TCRs that match their HLA type and address the most highly expressed targets in their tumor. We will use this set of TCRs to genetically reprogram their T cells to recognize these targets and the resulting engineered T cells will be infused back into the patient simultaneously as a multiplexed TCR-T therapy. 25 Table of Contents Our Strategy to Treat Solid Tumors with Multiplexed TCR-T Therapy TCR-Ts for the Treatment of Solid Tumors Immunotherapy has reshaped the treatment of solid tumors by demonstrating that tumor shrinkage, eradication, and long-term durable responses can be obtained by stimulating the patient’s own immune system to attack their cancer cells. Immune checkpoint inhibitors, such as nivolumab or pembrolizumab, work by unleashing anti-cancer T cells that are already present in a patient’s tumor, enabling those T cells to recognize and eliminate their cancer. For patients who respond to checkpoint inhibitors, these agents have been shown to be very effective. However, only a subset of patients responds to checkpoint inhibitors, highlighting the need for T cell-based therapies that can treat those patients who do not respond. Despite their efficacy in only a subset of patients, checkpoint inhibitors have annual sales of about $25 billion in the U.S. One reason why patients do not respond to current immunotherapy treatments is that they lack T cells with highly active TCRs that recognize cancer-specific antigens in their tumors. By reprogramming the patient’s own T cells to recognize these targets, we believe that we can expand the dramatic responses observed with checkpoint inhibitor therapy to the patients for whom these therapies are ineffective. Our Solution Our solid tumor program is based on the premise that if we can understand how T cells naturally fight cancer, we can use this information to design life-changing TCR-Ts for virtually any patient with cancer. Our discovery process begins with identifying patient T cells that are actively driving their clinical response to immunotherapy. We then use TargetScan to determine the precise targets of these highly active TCRs. Our discovery efforts are initially focused on patients with head and neck cancer who respond to checkpoint inhibitor therapy and patients with melanoma who respond to TIL therapy. These cancers represent tumor types with a high degree of T cell infiltration and strong responses to immunotherapy, which provides us with clinically active T cells from which we can discover novel TCR/target pairs. We have found that targets discovered in one type of cancer are often expressed in other cancers as well, enabling broader clinical development of our TCR-T candidates. The tumor types we are focused on also express several known targets that were previously discovered from patient T cells. We are using ReceptorScan to discover highly active TCRs for these previously identified targets to complement the discovery of our novel TCR/target pairs. Finally, the ImmunoBank will allow us to target multiple HLA types to prevent target loss and increase durability of response. Novel Targets Identified from Patients with Head and Neck Cancer One of the ways we identify anti-cancer TCRs is by focusing on T cells that clonally expand in a tumor when the patient responds to checkpoint inhibitor therapy. Some of this work is being performed under collaborative research agreements with various academic institutions. Using single cell sequencing, our collaborators determined the TCR sequences of thousands of T cells in the tumors of patients with head and neck cancer before and after immunotherapy. This analysis also revealed the frequency of each T cell clone in the tumor samples. As an example, if a particular TCR sequence is observed at 0.05% frequency in the tumor before the patient receives immunotherapy and then increases to 5% after the tumor starts to shrink, the T cell has clonally expanded 100-fold and is likely to have played a causal role in driving the patient’s clinical response. Certain TCR sequences are not detectable in the pre-treatment biopsy but are observed at high frequency in the post-treatment tumor. These emerging clones are also potential candidates for driving the patient’s 26 Table of Contents clinical response. An illustrative example of T cell sequencing data from one patient with head and neck cancer who had a complete response to immunotherapy can be found below. Clinically Relevant Anti-Cancer T Cells Identified Through T Cell Sequencing Novel Targets Identified from Patients with Melanoma Another approach we use to identify clinically relevant anti-cancer T cells is to analyze T cells from patients with melanoma who respond to TIL therapy. Using single cell sequencing, we determine the TCR sequences of the T cells in the responding patient’s TIL therapy product and focus on the most abundant T cell clones. We have found that TIL therapy products are often dominated by as few as two or three clones, further increasing our confidence that these TCRs played a causal role in fighting the patient’s cancer. To increase the throughput of our discovery efforts, we have used TargetScan in a more directed manner to screen sub-libraries of protein fragments that focus on particular classes of tumor antigens. For example, we built a sub-library that focuses on cancer/testis antigens, or CTAs, which are genes that typically play a role in embryonic development but are not expressed in any adult tissues other than testes. T cells do not infiltrate testes and cells in the testes have very low levels of MHC proteins, making testes an immune-privileged site that will not be targeted by engineered T cells in the context of cell therapy. CTA genes are frequently found to be expressed in tumor cells and often play a role in causing cancer. Several well-recognized targets in development for TCR-T therapy are CTAs, including NY-ESO-1 and MAGE-A4. We are focused on the discovery of novel targets within this class of antigens and have built a TargetScan library comprising 40,000 fragments that cover 1,600 CTA genes. Because this library is substantially less complex than our genome-wide Oncology Target Discovery Library, we can screen the TargetScan library with dozens of TCRs simultaneously. For example, we screened 35 TCRs derived from 11 patients with melanoma who received TIL therapy. In a single screen, we identified two TCR/target pairs that recognize CTAs, including the antigen target for one of our lead solid tumor product candidates, TSC-201, which we recently disclosed as MAGE-C2, and TSC-202, which we recently disclosed as MAGE-A4. TCR and Target Validation Process When we discover novel TCR/target pairs, we first determine if the gene that encodes the target is expressed at high levels in normal tissue. We found that TSC-201 (MAGE-C2) is exclusively expressed in testis, which is an immune privileged tissue and, as a result, should not pose a significant safety concern. We also examined how frequently the target is expressed in various solid tumors. In the screen, MAGE-C2 was overexpressed in a high percentage of melanoma tumor samples as well as in several other tumor types, including non-small cell lung cancer, or NSCLC, and head and neck cancer. 27 Table of Contents Next, as part of our discovery process, we test if the TCRs discovered with our approach can kill cancer cells that naturally express the relevant target and specific HLA type. As shown below on the left, when T cells expressing the TCR that recognizes MAGE-C2 are cultured with melanoma cell lines that naturally express different levels of MAGE-C2, such as A101D and SKMEL5, the degree to which the T cells get activated correlates with the expression level of MAGE-C2 in the melanoma cells. In addition, the T cells kill melanoma cells expressing high levels of MAGE-C2, as shown below on the right but do not kill cells that express low levels of MAGE-C2, which highlights the selectivity of the TCR for MAGE-C2. Finally, to reduce the risk that a TCR discovered in a targeted screen recognizes any problematic off-target interactions, we re-screen the TCR using SafetyScan and our genome-wide library. When the TCR that recognizes MAGE-C2 was re-screened using our Oncology Target Discovery Library, which includes protein fragments spanning every normal protein encoded in the human genome, only one potential off-target interaction was observed. We subsequently identified several cell lines that naturally express the full-length protein from which the off-target antigen was derived and found that T cells engineered with the TCR do not recognize or kill these cells. Although the TCR recognizes target cells overexpressing protein fragments containing this off-target antigen, it does not recognize cells expressing the full-length protein at normal levels. This shows that our genome-wide screen detects potential off-targets with very high sensitivity, and that not all off-targets detected in this manner are problematic. In the event, however, that a TCR exhibits problematic off-target effects, we can use ReceptorScan to discover alternative TCRs that have similar anti-cancer effects but do not cross-react with proteins expressed at high levels on normal tissue or critical organs. To further expand the pool of addressable patients with our TSC-200 series of product candidates, we can also use ReceptorScan to identify TCRs recognizing antigens on the same target protein that are presented by different HLA alleles. Ultimately, we believe this strategy has the potential to enable multiplexed TCR-T therapy in which a patient is treated with more than one TCR for the same target protein, presented on two different HLA alleles. This approach could reduce the risk of resistance arising from loss, downregulation, or mutation of individual HLA genes. TSC-20X Series Our six clinical-stage solid tumor TCR-T candidates include a combination of known targets, such as HPV16 for TSC-200, MAGE-A4 for TSC-202, PRAME for TSC-203, and MAGE-A1 for TSC-204, as well as a target that is a novel antigen for TCR-T, MAGE-C2 for TSC-201. All of these targets are frequently expressed in the solid tumors of interest to us, including melanoma, head and neck cancer, NSCLC, cervical cancer, ovarian cancer, and anogenital cancer. In 2023, it is estimated that in the U.S., approximately 100,000 patients were diagnosed with melanoma, 67,000 with head and neck cancer, 200,000 with NSCLC, 14,000 with cervical cancer, 20,000 with ovarian cancer, and 18,000 with anogenital cancer. We have advanced a combination of known and novel targets into clinical development, which is allowing us to use the product candidates targeting known antigens as backbones for our initial clinical trials evaluating multiplexed TCR-T therapy. For example, we plan to evaluate TSC-203, which targets PRAME, a well-known and clinically validated tumor-specific protein, in combination with TSC-201 targeting MAGE-C2. TSC-200 (HPV16) In parallel with our TargetScan discovery efforts in head and neck cancer, we are using ReceptorScan to discover highly active TCRs that target antigens in human papilloma virus, or HPV, for our TSC-200 program. Over 25% of head and neck cancers are caused 28 Table of Contents by HPV infection, including up to 70% of oropharangeal cancers. HPV antigens are a particularly compelling set of targets as HPV proteins drive tumorigenesis in these cancers, which means that these proteins are (1) present in every tumor cell in an HPV-positive tumor and (2) essential to the survival of the tumor cell. In addition to head and neck cancers, HPV is found in more than 90% of cervical and anogenital cancers as well as over 60% of vaginal, vulval, and penile cancers. Recent Phase 1 clinical data from the National Cancer Institute showed tumor regression with objective clinical responses in 50% of patients with metastatic HPV-positive cancers who were treated with a TCR-T candidate targeting HPV16, which we believe provides clinical support for the inclusion of an HPV16-targeting TCR-T, TSC-200-A0201, in our multiplexed TCR-T treatment strategy. We have identified over a thousand TCRs that recognize HLA-A*02:01-specific antigens derived from HPV16 and have advanced TSC-200-A0201 (HPV16, HLA-A*02:01), into Phase 1 development. We also intend to extend our discovery efforts to include additional HPV16-derived antigens presented on other HLA types as the program advances, such as TSC-200-C0702 (HPV16, HLA-C*07:02), currently in discovery. TSC-201 (MAGE-C2) We are developing the TSC-201 series of candidates as TCR-Ts targeting melanoma-associated antigen C2, or MAGE-C2. We initially identified MAGE-C2 as the target of T cells from a melanoma patient responding to TIL therapy. MAGE-C2 is a CTA that is exclusively expressed in testis and is not expressed in normal adult tissues. The testis is an immune-privileged tissue and, as a result, we believe that targeting MAGE-C2 should not pose a significant safety concern. In addition, MAGE-C2, which contributes to tumorigenesis by suppressing the cellular mechanisms responsible for controlling cell division, is selectively expressed across multiple different types of tumors, including approximately 50% of melanomas, approximately 25% of head and neck cancers, and approximately 50% of non-small cell lung cancers. Tumors expressing MAGE-C2 have been shown to be associated with metastasis and poor patient survival. We are currently advancing three MAGE-C2 TCRs; TSC-201-B0702 (MAGE-C2, HLA-B*07:02), currently in Phase 1 development; TSC-201-A0201 (MAGE-C2, HLA-A*02:01), currently in discovery; and TSC-201-A2402 (MAGE-C2, HLA-A*24:02), currently in discovery. We are also using ReceptorScan to identify additional TCRs for MAGE-C2 epitopes presented on other HLA alleles to further expand the ImmunoBank and increase the addressable patient population. TSC-202 (MAGE-A4) We are developing the TSC-202 series of candidates as TCR-Ts targeting melanoma-associated antigen 4, or MAGE-A4. MAGE-A4 is a clinically established CTA that contributes to tumorigenesis by interfering with cell cycle arrest. MAGE-A4 is expressed in 33% of cervical cancers enabling multiplexing with TSC-200, and MAGE-A4 is expressed in 50% of non-small cell lung cancers, 40% of head and neck cancers, and 30% of melanomas. Using ReceptorScan, we have identified thousands of TCRs that recognize multiple HLA-A*02:01-specific epitopes derived from MAGE-A4 and have advanced one MAGE-A4 TCR-T, TSC-202-A0201, into lead optimization. TSC-203 (PRAME) We are developing the TSC-203 series of candidates as TCR-Ts targeting Preferentially Expressed Antigen in Melanoma, or PRAME. Like MAGE-C2, PRAME contributes to tumorigenesis by suppressing cellular signals that control cell division, and higher expression levels of PRAME in tumors correlate with increased metastasis and poor patient outcomes. PRAME is a CTA that, like MAGE-C2 and MAGE-A4, is absent in adult tissues except in the ovaries and testis. Approximately 50% of NSCLCs, approximately 25% of cervical cancers, and approximately 90% of both melanomas and head and neck cancers express PRAME. Moreover, PRAME expression is homogeneous within these tumors, which we believe makes it an attractive target for multiplexed TCR-T therapy. Using ReceptorScan, we have identified thousands of TCRs across multiple PRAME-derived epitopes presented on HLA-A*02:01. We are currently advancing three PRAME TCR-Ts; TSC-203-A0201 (PRAME, HLA-A*02:01), currently in Phase 1 development; TSC-203-B0702 (PRAME, HLA-B*07:02), currently in lead optimization; and TSC-203-A2402 (PRAME, HLA-A*24:02) currently in discovery. In addition, we are using TargetScan on clinically active TCRs from patients with melanoma and head and neck cancer to identify novel PRAME epitopes presented on other HLA types. TSC-204 (MAGE-A1) We are developing the TSC-204 series of candidates as TCR-Ts targeting melanoma-associated antigen 1, or MAGE-A1. MAGE-A1 is a cancer/testis gene frequently overexpressed in a wide variety of solid tumors, including approximately 45% of head and neck cancers, 50% of melanomas, 50% of cervical cancers and 50% of non-small cell lung cancers. Using our TargetScan platform, we initially identified MAGE-A1 as one of the targets of expanded T cells from a head and neck cancer patient responding to checkpoint inhibitor therapy. Multiple different TCRs from this patient recognize a novel HLA-C*07:02-restricted epitope of MAGE-A1, and one of these TCRs is the basis of TSC-204-C0702 (MAGE-A1, HLA-C*07:02), currently in phase 1 development. In addition to this TCR-T candidate, we further expanded the TSC-204 series by using ReceptorScan to identify additional TCRs for MAGE-A1 epitopes presented on several other common HLA alleles to further expand the addressable patient population. We are currently advancing five MAGE-A1 29 Table of Contents TCR-Ts: TSC-204-A0201 (MAGE-A1, HLA-A*02:01), currently in Phase 1 development; TSC-204-C0702 (MAGE-A1, HLA-C*07:02), currently in Phase 1 development; TSC-204-A0101 (MAGE-A1, HLA-A*01:01) currently in Phase 1 development; TSC-204-A0301 (MAGE-A1, HLA-A*03:01) currently in discovery; and TSC-204-B0702 (MAGE-A1, HLA-B*07:02) currently in discovery. In addition to our six lead solid tumor TCR-T candidates, we have identified approximately 200 novel antigens as targets of tumor infiltrating T cells from patients who are responding to immunotherapy using TargetScan. Although target validation naturally results in attrition, it is clear that tumor-resident T cells recognize many more shared antigens than have been reported to date. Many of the antigens we have identified are expressed across multiple solid tumor types and some have expression levels comparable or superior to targets currently in clinical development by others. We are currently in the process of validating several of these additional novel antigens and identifying potential TCR/target pairs using our platform technologies. We plan to continuously expand the ImmunoBank with TCRs for both known and novel targets as well as address different HLA types to enable customized multiplexed TCR-T therapy candidates while also addressing the potential issue of HLA loss leading to resistance for a wide range of solid tumor patients. Clinical Development Plan for Our Solid Tumor Program For the initial first-in-human studies for our TSC-20X series of TCR-T candidates, we are evaluating multiple TCRs in parallel to determine the safety and preliminary efficacy of multiplexed TCR-T therapy. The FDA has cleared our IND application for T-Plex, which serves as the primary IND application for our solid tumor program, enabling customized simultaneous administration of TCR-Ts to be administered to patients based on the targets and HLAs expressed in their tumors. Specific TCRs for each patient will be chosen from the ImmunoBank consisting of high affinity, naturally occurring TCRs that recognize a variety of prevalent cancer-specific targets and are associated with common HLA types. Each unique TCR-T will be filed as a secondary IND application and will reference the primary T-Plex IND application. In addition to the T-Plex IND application, the FDA has cleared secondary IND applications for six TCR-T product candidates: TSC-203-A0201 (PRAME, HLA-A*02:01); TSC-200-A0201 (HPV16, HLA-A*02:01); TSC-201-B0702 (MAGE-C2, HLA-B*07:02); TSC-204-A0201 (MAGE-A1, HLA-A*02:01); TSC-204-C0702 (MAGE-A1, HLA-C*07:02); and TSC-204-A0101 (MAGE-A1, HLA-A*01:01). We have initiated a multicenter Phase 1 clinical trial to evaluate the safety, preliminary efficacy, and feasibility of repeat dosing of multiplexed TCR-T therapy. We plan to enroll patients with non-small cell lung cancer, melanoma, head and neck cancer, ovarian cancer, cervical cancer, and anogenital cancer. We expect that many of the clinical trial sites enrolling patients in our hematologic malignancies program are planning to join our solid tumor Phase 1 study. We are currently enrolling patients in the screening protocol of this study, with patient dosing expected to commence in the first quarter of 2024. We plan to further populate the ImmunoBank with additional targets and HLA types, including cancer/testis antigens and TCRs targeted at epitopes of HPV. We envision these HPV-targeting TCRs will serve as a backbone therapy for patients with HPV-positive malignancies, including head and neck, cervical, and anogenital cancers. According to the Centers for Disease Control, the incidence of HPV-positive cancers in the U.S. is approximately 46,000 cases per year, with five-year survival rates ranging from approximately 50% to 70%. The targets of TSC-201, TSC-202, TSC-203, and TSC-204 are also frequently expressed in the solid tumors of interest to us, as shown below. 30 Table of Contents Cancer Expression Levels for the Targets of our Lead Solid Tumor Programs After establishing single agent safety for each of our initial solid tumor TCR-T candidates in a multi-arm Phase 1 clinical trial, we plan to test our TSC-200 series of TCR-Ts in combination with other TCRs in the ImmunoBank in patients who are positive for the respective targets of these therapies. We will also explore three-TCR simultaneous administrations in patients who are positive for the three respective targets. Because the targets of TSC-201, TSC-202, TSC-203, and TSC-204 are also frequently expressed in melanoma and NSCLC, we will also explore various simultaneous administrations of these TCR-T candidates in patients with HPV-negative head and neck cancer, melanoma, and NSCLC. A summary of our planned Phase 1 clinical strategy is shown below. TSC-200 Series Dose Escalation Scheme Provides Rapid Path to Testing and Expanding Multiplexed TCR-T in Phase 1 31 Table of Contents Anticipated timeline As we advance our solid tumor program, we anticipate submitting IND filings for additional TCRs throughout 2024. As we continue to discover and validate TCR/target pairs, we aim to continue to file additional IND applications and introduce those solid tumor TCR-T candidates into this multi-arm basket-style Phase 1 clinical trial. We believe this trial will serve as the first step towards our long-term goal of expanding the ImmunoBank to provide customized multiplexed TCR-Ts for virtually any patient with a solid tumor malignancy. We plan to share initial data from the singleplex cohorts as well as initial multiplex data for our first simultaneous administrations of TCRs under T-Plex in 2024, with long-term duration of response data for multiplexed therapy anticipated in 2025. ImmunoBank – Flexible Content for Diverse Platforms Our current clinical development strategy is based on autologous T cell engineering. As the field of T cell engineering evolves, a wide variety of additional manufacturing platforms are being developed that may further improve TCR-T products. For example, companies such as Lyell Immunopharma, Inc. are developing methods to enhance autologous T cell engineering to provide improved duration of efficacy, while companies such as Allogene Therapeutics, Inc. are developing ways to engineer allogeneic T cells and companies such as Umoja Biopharma, Inc. are developing ways to engineer T cells in vivo . All of these engineering platforms require validated “content” – TCRs that recognize tumor-specific antigens on cancer cells without recognizing problematic off-targets. As we advance the ImmunoBank of TCRs through clinical development, we intend to continue to build our own manufacturing platform, while simultaneously investigating novel T cell engineering platforms once they have established safety and efficacy. Ultimately, we aspire to build the largest collection of validated TCR “content” that can be used with a variety of T cell engineering platforms. Expansion Opportunities Beyond Oncology Our primary focus is on the development of T cell therapies to treat cancer. However, T cells play a fundamental role in many other disease areas, such as infectious disease and autoimmune disorders. We believe that our TargetScan technology is well suited to discover novel antigens for the development of therapeutics, diagnostics, and vaccines in these other areas. We intend to build additional corporate value by opportunistically pursuing collaborations with strategic partners for applications of our platform technologies outside our core focus. Other Diseases TargetScan can also be used for novel target discovery in additional infectious diseases and autoimmune disorders. For example, infections such as tuberculosis, influenza, and HIV have been shown to be T cell-mediated and are associated with high mortality rates. In addition, many autoimmune disorders such as rheumatoid arthritis, psoriasis, and scleroderma are largely T cell-mediated, but with poorly defined instigating self-antigens. Our TargetScan technology, which provides an unbiased, genome-wide method to discover the natural targets of disease-relevant T cells, is well positioned to identify these self-antigens. We believe the discovery of these targets could enable the development of novel, more targeted therapeutic approaches to treat these diseases. License and Collaboration Agreements Collaboration Agreement with Amgen On May 8, 2023, we entered into a Research Collaboration and License Agreement with Amgen Inc. (Amgen), or the Amgen Agreement, to identify antigens recognized by T cells in patients with Crohn’s disease utilizing our proprietary target discovery platform, or TargetScan. Under the terms of the Amgen Agreement, Amgen will then evaluate a variety of modalities to create therapeutics based on targets discovered by TScan and will retain all global development and commercialization rights. Amgen made an upfront payment of $30 million to us and we are eligible to earn success-based milestone payments of over $500 million, based upon the achievement of certain development and commercial milestones, as well as tiered single-digit royalty payments on net sales of products developed from the collaboration, subject to reductions set forth in the Amgen Agreement. Collaboration and License Agreement with Novartis On March 27, 2020, we entered into a Collaboration and License Agreement with Novartis Institutes for BioMedical Research, Inc. (Novartis) (such agreement, the Novartis Agreement). Pursuant to the Novartis Agreement, we have received an aggregate of $20.0 million of cash representing the upfront payment and research funding totaling $10 million. We granted Novartis and its affiliates options to obtain exclusive, royalty-bearing, sublicensable, transferable, worldwide licenses to certain target antigens identified in performance of the Novartis Agreement and corresponding T cell receptors for such target antigens to make, have made, import, use, sell or offer for sale, including to develop, manufacture, commercialize, register, hold or keep, have used, export, transport, distribute, promote, market or have sold or otherwise dispose of such target antigens and corresponding T cell receptors. 32 Table of Contents The ownership of inventions (and resulting patent rights) created in performance of the collaboration was determined by inventorship. We retained our rights to (i) our intellectual property, (ii) programs that are not selected by Novartis, and (iii) our platform improvements, which were not considered collaboration technology. Our collaboration with Novartis concluded in March 2023. Exclusive Patent License Agreement with BWH On December 5, 2018, we entered into an Exclusive Patent License Agreement with The Brigham and Women’s Hospital, Inc., or BWH, as amended on July 26, 2019 and further amended and restated on April 20, 2021, or, collectively, the BWH Agreement, pursuant to which we obtained an exclusive, sublicensable, worldwide license to practice under certain of BWH’s patent rights for identifying T cell epitopes, which are relevant to our TargetScan technology for identifying potential therapeutic products. The original 2018 BWH Agreement granted us the right to practice BWH’s patent rights in a certain field of use, MHC Class I License Field. In connection with the amended and restatement of the BWH Agreement in 2021, we expanded the field of use in which we are authorized to practice BWH’s patent rights to include MHC Class II uses and applications in exchange for certain additional payments to BWH. We are obligated to use commercially reasonable efforts to develop and commercialize at least one product or process that practices the licensed patent rights and at least one therapeutic or diagnostic product or process directed to an epitope identified through practicing the licensed patent rights. Upon execution of the amendment of the BWH Agreement dated April 20, 2021, we paid an additional one-time fee of $466,500. We are required to pay BWH up to an aggregate of $12.72 million upon the achievement of certain clinical, regulatory and sales milestones for therapeutic products and processes. We are obligated to pay a low double-digit percentage of all non-royalty income we receive under sublicenses of BWH’s patent rights. We are also obligated to pay a low single-digit percentage of all non-royalty income we receive under agreements with third parties, or Collaborators, where we practice under BWH’s patent rights in connection with the research or development of one or more therapeutic products or processes with or for such third party, or Collaboration Agreements. We are also obligated to pay tiered royalties in the high single-digit percentage range on annual net sales of products and processes that practice the licensed patent rights and in the low single-digit percentage range on annual net sales of therapeutic and diagnostic products and processes directed to an epitope identified through practicing the licensed patent rights (other than those sold by Collaborators), with the royalty percentage for such products and processes decreasing to lower than one-percent royalties if directed to epitopes identified through practicing the licensed patent rights after December 31, 2019. For therapeutic and diagnostic products and processes directed to an epitope identified through practicing the licensed patent rights and sold by a Collaborator, we are obligated to pay lower than one-percent royalties of the Collaborator’s annual net sales of such products and processes. For products and processes sold by us, our affiliates or sublicensees, such royalties only apply to products and processes directed to epitopes in a defined field of use MHC Class I field identified prior to December 31, 2022, and products and processes based on epitopes in the MHC Class II field identified prior to September 30, 2023. For products or processes directed to epitopes identified under a Collaboration Agreement, such royalties apply regardless of when the epitopes were identified. For each applicable product or process, the royalty term continues until the tenth (10 th ) anniversary of the first commercial sale of such product or process. The royalty rates are also subject to reduction upon certain other events. Within 60 days of each anniversary of December 5 th , we are obligated to pay BWH a non-refundable, mid-five-figure minimum annual royalty, which amount is creditable against royalties subsequently due on net sales of products and processes in such calendar year. The BWH Agreement will terminate upon the later of (a) the last to expire or abandoned valid claim within the licensed patents, and (b) one year after the last sale for which a royalty is due. The current expected expiration date for the last-to-expire licensed patent right is June 8, 2038 (absent any adjustments or extensions of term). We also have the right to terminate the BWH Agreement in its entirety or on a country-by-country basis, for any reason upon 90 days’ prior written notice to BWH. BWH may terminate the BWH Agreement: (i) without notice if we fail to maintain insurance required by the BWH Agreement; (ii) upon notice within 60 days of our bankruptcy; (iii) upon notice within 60 days after notice by BWH of our default in the performance of any obligation under the BWH Agreement that is not cured within such 60-day period; (iv) if we fail to make any payments due under the BWH Agreement and do not cure such failure within 10 days after receiving BWH notice thereof; or (v) if we or any of our affiliates challenge the validity, enforceability or scope of any of the patent rights licensed to us under the BWH Agreement. Non-Exclusive License Agreement with Provincial Health Services Authority On October 15, 2020, we entered into a Non-Exclusive License Agreement with the Provincial Health Services Authority of British Columbia, or PHSA, and such agreement, the PHSA Agreement. Pursuant to the PHSA Agreement, we obtained a non-exclusive, perpetual, non-transferable, sublicensable, worldwide license to practice certain of PHSA’s patent rights for identifying T cell epitopes, 33 Table of Contents which epitopes are relevant to our platform for identifying potential TCR-Ts. Any sublicenses we grant to PHSA’s patent rights must also include a license of our own intellectual property; we are not permitted to sublicense PHSA’s rights on a standalone basis. Pursuant to the PHSA Agreement, we paid PHSA a one-time, non-refundable upfront fee of $500,000 as well as reimbursement for previously incurred patent prosecution costs of approximately $50,000. Starting on the first anniversary of the effective date of the PHSA Agreement and continuing for five years thereafter, we are required to pay PHSA a mid-five-figure annual license fee, of which the first installment has been paid. In addition, we are obligated to pay a mid-six-figure fee for each sublicense and each further sublicense granted by one of our sublicensees or a sublicensee of our sublicensee (through multiple tiers) of the rights granted to us under the PHSA Agreement. The PHSA Agreement will terminate upon the last to expire patent licensed under the PHSA Agreement. We also have the right to terminate the PHSA Agreement at any time, but such termination will not be effective until the later of (a) October 16, 2023, and (b) the date we have paid PHSA total aggregate fees equal to the upfront fee plus five years of annual license fees totaling $750,000. PHSA may terminate the PHSA Agreement upon giving us two separate written notices at least 30 days apart if: (i) we or any of our affiliates challenge the validity, enforceability or scope of any of the patents licensed to us under the PHSA Agreement; (ii) we owe unpaid fees due under the PHSA Agreement in excess of $100,000; or (iii) we breach material terms of the PHSA Agreement regarding sublicense restrictions (such as failing to pay the sublicense fee or sublicensing PHSA technology on a standalone basis) or our obligation to indemnify PHSA for damages resulting from our research or commercialization of PHSA’s patent rights and, in each case described above, such termination will be effective only if we fail to cure such breach after receiving PHSA’s two separate notices. Royalty Agreement In connection with our incorporation in April 2018, we entered into a royalty agreement with one of our founders. We amended and restated this royalty agreement in June 2018 and our founder assigned his rights and obligations under the royalty agreement to one of his affiliated entities in January 2021. Pursuant to the royalty agreement, we are required to pay him a royalty of 1% of net sales (as defined in the royalty agreement) of any product sold by us or by any of our direct or indirect licensees for use in the treatment of any disease or disorder covered by a pending patent application or issued patent held or controlled by us as of the last date that the founder was providing services to us as a director or consultant under a written agreement. Royalties are payable with respect to each applicable product on a country-by-country and product-by-product basis, beginning on the first commercial sale of the first royalty-bearing product and ending on the later of (i) the date on which the exploitation of such royalty-bearing product is no longer covered by such patent in such country or (ii) the 15th anniversary of the first commercial sale of the first royalty-bearing product in such country. We may not assign our rights and obligations under the royalty agreement except in the event of a change in control relating to our company. The term of the royalty agreement continues until expiration of the last applicable royalty term. Manufacturing We have built in-house cell therapy manufacturing capabilities as one of the key components of our platform. The manufacturing of cell therapies requires the integration of several distinct components. Primary human blood cells are the source of T cells, along with a vector that delivers the desired genetic elements into these T cells. As a more operationally flexible and cost-efficient alternative to lentivirus, we have developed a manufacturing platform to genetically engineer T cells using a transposon/transposase system, which we refer to as T-Integrate. We are designing our programs to use a transposon vector and corresponding transposase enzyme, which is derived from sfR fall armyworm, to deliver our TCRs into the genome of T cells. Our transposon/transposase system effectively inserts our TCRs and other exogenous genes, such as CD8, at random locations in the genome. The transposon will be delivered as a Nanoplasmid and has no antibiotic selection element, reducing the risk of inadvertent transmission of antibiotic resistance into T cells. The transposase will be delivered as mRNA. mRNA is transiently expressed in the cell, reducing exposure of cells to prolonged transposase activity, which could result in multiple transposition events where the transposon would be moved around the genome. We have developed a manufacturing process currently producing product for clinical studies, using industry standard equipment and instrumentation. The equipment and instrumentation used in our manufacturing facility allows for functionally closed processes in a small footprint. For clinical product manufacturing, we use single-use bag and tubing kits, supplies, and process reagents that are available from well-established vendors who specialize in supplying clinical grade reagents for the cell and gene therapy industry. Our TCR-T candidates are released and characterized using well-developed analytical methods. The final product used in clinical studies is cryopreserved, simplifying logistics and reducing risk of delivery failures to support patient dosing. We have controls and safeguards throughout the entire process to ensure product identity, integrity, sterility, and chain of custody. A clearly defined and documented manufacturing process, performed by trained operators using specialized instrumentation in an appropriately designed, commissioned, and operated manufacturing facility is critical for the manufacturing of safe, effective, and well-characterized cell therapies. 34 Table of Contents Our cell product manufacturing facility in Waltham, MA has been designed and built to support multiple programs through Phase 1 and Phase 2 clinical development, with a projected capacity to support up to 250 TCR-T components per year. We believe internalizing our manufacturing process and product testing enables us to better control this key aspect of clinical development and reduces the risk of program delay due to third-party reliance. We expect to revisit our manufacturing process prior to commencing registrational trials and may use third-party contract manufacturing organizations (CMO) to increase our capacity in support of manufacturing product candidates for our registrational trials. Competition We believe our novel and proprietary platform technologies, TargetScan, SafetyScan, and ReceptorScan, and our in-house cell therapy expertise constitute a meaningful competitive advantage in successfully developing novel and highly safe and effective treatments for cancer. However, the biopharmaceutical industry in general, and the cell therapy field in particular, is characterized by rapidly advancing and changing technologies, intense competition, and a strong emphasis on intellectual property. We face substantial and increasing competition from many different sources, including large and specialty biopharmaceutical companies, academic research institutions, governmental agencies, and public and private research institutions. Competitors may compete with us in hiring scientific and management personnel, establishing clinical study sites, recruiting patients to participate in clinical trials, and acquiring technologies complementary to, or necessary for, our programs. We face competition from segments of the pharmaceutical, biotechnology and other related markets that pursue the development of TCR-based or cell-based therapies for the treatment of cancer. We expect to compete with a number of other TCR-based companies, utilizing both cell therapy and other therapeutic modalities, such as Immatics N.V., Adaptimmune Therapeutics, Plc., Affini-T Therapeutics, Inc., Medigene AG, T-Knife GmbH, Enara Bio Ltd., Immunocore Holdings, Plc., and 3T Biosciences Inc. We may also face competition from companies focused on other T cell therapies (e.g., TIL, CAR-T, gammadelta T cells) such as Iovance Biotherapeutics, Inc., Instil Bio, Inc., Achilles Therapeutics plc, Kite Pharma, Inc., a subsidiary of Gilead, Inc. (including Yescarta, which is approved for the treatment for large B cell lymphoma or follicular lymphoma, two types of non-Hodgkin lymphoma), Juno Therapeutics, Inc., a subsidiary of Bristol-Myers Squibb, Inc., Regeneron Pharmaceuticals, Inc., through their acquisition of 2seventy Bio, Inc.’s research pipeline, AstraZeneca plc, through their acquisition of Gracell Biotechnologies, Inc., Legend Biotech Corporation, Autolus Therapeutics plc, Sana Biotechnology, Inc., Lyell Immunopharma, Inc., Allogene Therapeutics, Inc., Gadeta B.V., and Adicet Bio, Inc. There are also companies utilizing other cell-based approaches that may be competitive to our product candidates. For example, companies such as Takeda Pharmaceutical Company, Ltd., Sanofi S.A., through their acquisition of Kiadis Pharma N.V., Celyad, S.A., ImmunityBio, Inc., Celularity, Inc., Fate Therapeutics, Inc., and Nkarta, Inc. are developing therapies that target and/or engineer natural killer, or NK, cells. In addition, for our lead programs, TSC-100 and TSC-101, we may face competition from BlueSphere Bio, VOR Biopharma, Inc., IN8bio, Inc., and Marker Therapeutics, Inc., who are also developing cell therapies in the post-HCT setting. The named companies are not fully inclusive of all possible competitive threats. Furthermore, we also face competition more broadly across the oncology market for cost-effective and reimbursable cancer treatments. The most common methods of treating patients with cancer are surgery, radiation, and drug therapy, including chemotherapy, hormone therapy, biologic therapy, such as monoclonal and bispecific antibodies, immunotherapy, cell-based therapy, and targeted therapy, or a combination of any such treatments. There are a variety of available drug therapies marketed for cancer. In many cases, these drugs are administered in combination to enhance efficacy. While our TCR-T candidates, if any are approved, may compete with these existing drugs and other therapies, to the extent they are ultimately used in combination with or as an adjunct to these therapies, our TCR-Ts may not be competitive with them. Some of these drugs are branded and subject to patent protection, and others are available on a generic basis. As a result, obtaining market acceptance of, and gaining a significant share of the market for, and commanding a certain price for any of our TCR-Ts that we successfully introduce to the market may pose challenges. In addition, many companies are developing new oncology therapeutics, and we cannot predict what the standard of care will be as our product candidates progress through clinical development. We could see a reduction or elimination in our commercial opportunity if our competitors develop and commercialize drugs that are safer, more effective, have fewer or less severe side effects, are more convenient to administer, are less expensive, are more accessible, or receive a more favorable label than our TCR-T candidates. Our competitors also may obtain FDA or other regulatory approval for their drugs more rapidly than we may obtain approval for ours, which could result in our competitors establishing a strong market position before we are able to enter the market. The key competitive factors affecting the success of all of our TCR-T candidates, if approved, are likely to be their efficacy, safety, convenience, accessibility, price, and the availability of reimbursement from government and other third-party payors. Intellectual Property 35 Table of Contents Our success depends in part on our ability to obtain, maintain and protect our proprietary technology and intellectual property and proprietary rights and to operate our business without infringing, misappropriating and otherwise violating the intellectual property and proprietary rights of third parties. We rely on a combination of patent applications, trademarks, trade secrets, and other intellectual property rights and measures to protect the intellectual property rights that we consider important to our business. We also rely on know-how and continuing technological innovation to develop and maintain our competitive position. We also seek to protect our proprietary rights by entering into confidentiality agreements and proprietary information agreements with suppliers, employees, consultants and others who may have access to our proprietary information. The steps we have taken to protect our trade secrets, trademarks, patent applications and other intellectual property and proprietary rights may not be adequate, and third parties could infringe, misappropriate or misuse our intellectual property. If this were to occur, it could harm our reputation and adversely affect our business, competitive position, financial condition or results of operations. As of the date hereof, our patent portfolio includes a patent family exclusively licensed from BWH, including a granted U.S. patent, a pending U.S. non-provisional patent application, and multiple foreign granted patents and non-provisional patent applications, relating to methods and compositions for identifying target antigens specific to T cells. In addition, we have filed applications in multiple patent families including multiple pending U.S. provisional patent applications, multiple granted foreign patents, and more than 70 pending international and foreign patent applications. The claims of these patent applications are directed toward various aspects of our therapy candidates and research programs, including compositions of matter directed to SARS-CoV-2 immunodominant antigens, anti-SARS-CoV-2 TCRs, anti-SARS-CoV-2 vaccines, anti-HA-1 TCRs (including the TSC-100 TCR-T candidate), anti-HA-2 TCRs (including the TSC-101 TCR-T candidate), anti-HPV TCRs (including the TSC-200 TCR-T candidate), anti-MAGE-C2 TCRs (including the TSC-201 TCR-T candidate), anti-PRAME TCRs (including the TSC-203 TCR-T candidate), and anti-MAGE-A1 TCRs (including the TSC-204 TCR-T candidate), as well as platform technologies including a phospholipid scrambling reporter-based T cell antigen screening platform and certain screening methods thereof, and a TCR multiplexing platform and certain therapeutic methods thereof. These patent applications, if issued, are expected to expire on various dates from 2038 through 2044, in each case without taking into account any possible patent term adjustments or extensions and assuming that appropriate maintenance and governmental fees are paid. Hematologic Malignancies Program Product Patent Families We have filed multiple pending patent applications covering aspects of our hematologic malignancies programs including claims to the composition-of-matter of TSC-100, TSC-101, and other anti-HA-1 and anti-HA-2 TCRs and related T cell therapies. The international Patent Cooperation Treaty (PCT) applications began to enter the national and regional phases in May 2023. The pending patent applications claim the benefit of priority from earlier-filed U.S. priority provisional patent applications filed in 2020 and 2021. We expect the issued Australian patents and any additional patents within this family, if issued, to expire no earlier than 2041 (without taking into account any possible patent term adjustments or extensions and assuming that appropriate maintenance and governmental fees are paid). Solid Tumor Program Product Patent Families We have filed multiple pending U.S. provisional and PCT international patent applications covering aspects of our solid tumor programs including claims to the composition-of-matter of anti-HPV, anti-MAGE-C2, anti-PRAME, anti-MAGE-A1 TCRs, and related T cell therapies. The pending patent applications began to enter the national and regional phases in October 2023. We expect any patents within this family, if issued, to expire no earlier than 2042 (without taking into account any possible patent term adjustments or extensions and assuming that appropriate maintenance and governmental fees are paid). Infectious Disease Product Patent Families We have filed multiple pending patent applications covering aspects of our infectious disease programs including claims to the composition-of-matter of SARS-CoV-2 immunodominant antigens, anti-SARS-CoV-2 TCRs, and the composition-of-matter of certain SARS-CoV-2 vaccines. These pending U.S., Australian, Canadian, European, Japanese, Argentine, Bangladeshi, Democratic Republic of the Congo, Pakistani, and Taiwanese patent applications claim the benefit of priority from earlier-filed U.S. priority provisional patent applications filed in 2020. We expect the issued Australian patent, the Democratic Republic of the Congo patent, and any additional patents within this family, if issued, to expire no earlier than 2041 (without taking into account any possible patent term adjustments or extensions and assuming that appropriate maintenance and governmental fees are paid). Certain of these pending patent applications are jointly owned by us and AHS Hospital Corporation, or AHS. AHS has exclusively licensed their interest in such patent applications to us. Platform Technology 36 Table of Contents We own a pending PCT patent application with claims that cover aspects of our reporter-based T cell antigen screening platform. We expect any claims within this family, if issued, to expire no earlier than 2041 (without taking into account any possible patent term adjustments or extensions and assuming that appropriate maintenance and governmental fees are paid). We also own a family of pending provisional patent applications with claims that cover multiplexed TCR compositions and certain therapeutic methods thereof. We expect any claims within this family, if issued, to expire no earlier than 2043 (without taking into account any possible patent term adjustments or extensions and assuming that appropriate maintenance and governmental fees are paid). Our pending patent applications may not result in issued patents and we can give no assurance that any patents that might issue in the future will protect our products or provide us with any competitive advantage. Moreover, U.S. provisional patent applications are not eligible to become issued patents until, among other things, we file a non-provisional patent application within 12 months of filing of one or more of our related provisional patent applications. With regard to such U.S. provisional patent applications, if we do not timely file any non-provisional patent applications, we may lose our priority date with respect to our provisional patent applications and any patent protection on the inventions disclosed in our provisional patent applications. While we generally intend to timely file non-provisional patent applications relating to our provisional patent applications, we cannot predict whether any such patent applications will result in the issuance of patents that provide us with any competitive advantage. For more information regarding the risks related to our intellectual property, please see “Risk Factors—Risks Related to Our Intellectual Property”. Third-Party Intellectual Property Rights For certain aspects of our business, we rely on certain technology and intellectual property rights that we in-license from third parties. We have an exclusive patent license from BWH to a patent family directed to aspects of a granzyme B (GzB)-based antigen screening technology platform, as well as compositions-of-matter and certain screening methods thereof (consisting of one granted U.S. patent, one pending U.S. patent application, a granted patent in each of Australia and Japan, and six foreign patent applications pending in Australia, Canada, China, Europe, Hong Kong, and Japan). Any patents issuing from the U.S. and foreign patent applications are expected to expire no earlier than 2038 (without taking into account any possible patent term adjustments or extensions and assuming that appropriate maintenance and governmental fees are paid). We also have a non-exclusive, perpetual, non-transferable patent license from PHSA to a patent family directed to granzyme-based antigen screening methods consisting of an issued U.S. patent that is expected to expire on August 4, 2035 (assuming that appropriate maintenance and governmental fees are paid) and issued Canadian patent that is expected to expire March 25, 2035 (assuming that appropriate maintenance and governmental fees are paid). We do not have any additional material licenses to any technology or intellectual property rights. As of the date hereof, we own or have rights to U.S. and foreign trademark registrations and applications that cover certain aspects of our business. Government Regulation FDA Regulation and Marketing Approval In the U.S., the FDA regulates drugs under the Federal Food, Drug and Cosmetic Act, or FDCA, and biologics under the Public Health Service Act, the regulations promulgated under both laws and other federal, state, and local statutes and regulations. Failure to comply with the applicable U.S. regulatory requirements at any time during the product development process, approval process or after approval may subject an applicant to administrative or judicial sanctions and non-approval of product candidates. These sanctions could include, among other things, the imposition by the FDA of a clinical hold on trials, the FDA’s refusal to approve pending applications or related supplements, withdrawal of an approval, untitled or warning letters, product recalls, product seizures, total or partial suspension of production or distribution, injunctions, fines, restitution, disgorgement, civil penalties, or criminal prosecution. Such actions by government agencies could also require us to expend a large amount of resources to respond to the actions. Any agency or judicial enforcement action could have a material adverse effect on us. The FDA and comparable regulatory agencies in state and local jurisdictions and in foreign countries impose substantial requirements upon the clinical development, approval, manufacture, distribution and marketing of pharmaceutical products. These agencies and other federal, state and local entities regulate research and development activities and the testing, manufacture, quality control, safety, effectiveness, labeling, packaging, storage, distribution, record keeping, approval, post-approval monitoring, advertising, promotion, sampling and import and export of our products. Our drugs must be approved by the FDA as biologics through the BLA approval process applicable to gene therapy product candidates, before they may be legally marketed in the U.S. Within the FDA, the FDA’s Center for Biologics Evaluation and Research, or CBER, regulates gene therapy products and has published guidance documents with respect to the development of these types of products. The FDA also has published guidance 37 Table of Contents documents related to, among other things, gene therapy products in general, their preclinical assessment, observing subjects involved in gene therapy studies for delayed adverse events, potency testing, and chemistry, manufacturing and control information in gene therapy INDs. The process required by the FDA before a biologic may be marketed in the U.S. generally involves the following: • completion of non-clinical laboratory tests, animal studies and formulation studies conducted according to Good Laboratory Practice, or GLP, or other applicable regulations; • submission of an IND application, which allows clinical trials to begin unless the FDA objects within 30 days; • performance of adequate and well-controlled human clinical trials to establish the safety and efficacy of the proposed drug or biologic for its intended use or uses conducted in accordance with FDA regulations and Good Clinical Practices, or GCP, which are international ethical and scientific quality standards meant to ensure that the rights, safety and well-being of trial participants are protected, and that the integrity of the data is maintained; • preparation and submission to the FDA of a BLA; • submission of a user fee for FDA review of the BLA; • review of the product by an FDA advisory committee, where appropriate or if applicable; • satisfactory completion of pre-approval inspection of manufacturing facilities and clinical trial sites at which the product, or components thereof, are produced to assess compliance with current Good Manufacturing Practice, or cGMP, requirements, and if applicable, the FDA’s current Good Tissue Practice, or cGTP, requirements, and of selected clinical trial sites to assess compliance with GCP requirements; and • FDA approval of a BLA which must occur before a biologic can be marketed or sold. Preclinical Studies Preclinical studies include laboratory evaluation of the purity and stability of the manufactured drug substance or active pharmaceutical ingredient and the formulated drug or drug product, as well as in vitro and animal studies to assess the safety and activity of the drug for initial testing in humans and to establish a rationale for therapeutic use. The conduct of preclinical studies is subject to federal regulations and requirements, including GLP regulations. The results of the preclinical tests, together with manufacturing information, analytical data, any available clinical data or literature and plans for clinical studies, among other things, are submitted to the FDA as part of an IND application. Companies usually must complete some long-term preclinical testing, such as animal tests of reproductive adverse events and carcinogenicity and must also develop additional information about the chemistry and physical characteristics of the drug and finalize a process for manufacturing the drug in commercial quantities in accordance with, or cGMP, requirements. The manufacturing process must be capable of consistently producing quality batches of the drug candidate and, among other things, the manufacturer must develop methods for testing the identity, strength, quality, and purity of the final drug product. Additionally, appropriate packaging must be selected and tested, and stability studies must be conducted to demonstrate that the drug candidate does not undergo unacceptable deterioration over its shelf life. IND Application and Clinical Trials Clinical trials involve the administration of the investigational product to human subjects under the supervision of qualified investigators in accordance with GCP requirements. Clinical trials are conducted under written study protocols detailing, among other things, the objectives of the study, the parameters to be used in monitoring safety and the effectiveness criteria to be evaluated. Prior to commencing the first clinical trial, an initial IND application, which contains the results of preclinical testing along with other information, such as information about product chemistry, manufacturing and controls and a proposed protocol, must be submitted to the FDA. The IND application automatically becomes effective 30 days after receipt by the FDA unless the FDA, within the 30-day time period, raises concerns or questions about the drug product or the conduct of the clinical trial and imposes a clinical hold. A clinical hold may also be imposed at any time while the IND application is in effect. In such a case, the IND-application sponsor must resolve any outstanding concerns with the FDA before the clinical trial may begin or re-commence. Accordingly, submission of an IND application may or may not result in the FDA allowing clinical trials to commence or continue. In addition to the submission of an IND application to the FDA before initiation of a clinical trial in the U.S., certain human clinical trials involving recombinant or synthetic nucleic acid molecules are subject to oversight of institutional biosafety committees, 38 Table of Contents or IBCs, as set forth in the National Institutes for Health, or NIH, Guidelines for Research Involving Recombinant or Synthetic Nucleic Acid Molecules, or NIH Guidelines. Under the NIH Guidelines, recombinant and synthetic nucleic acids are defined as: (i) molecules that are constructed by joining nucleic acid molecules and that can replicate in a living cell (i.e., recombinant nucleic acids); (ii) nucleic acid molecules that are chemically or by other means synthesized or amplified, including those that are chemically or otherwise modified but can base pair with naturally occurring nucleic acid molecules (i.e., synthetic nucleic acids); or (iii) molecules that result from the replication of those described in (i) or (ii). Specifically, under the NIH Guidelines, supervision of human gene transfer trials includes evaluation and assessment by an IBC, a local institutional committee that reviews and oversees research utilizing recombinant or synthetic nucleic acid molecules at that institution. The IBC assesses the safety of the research and identifies any potential risk to public health or the environment, and such review may result in some delay before initiation of a clinical trial. While the NIH Guidelines are not mandatory unless the research in question is being conducted at or sponsored by institutions receiving NIH funding of recombinant or synthetic nucleic acid molecule research, many companies and other institutions not otherwise subject to the NIH Guidelines voluntarily follow them. A sponsor who wishes to conduct a clinical trial outside the U.S. may, but need not, obtain FDA authorization to conduct the clinical trial under an IND application. If a foreign clinical trial is not conducted under an IND application, the sponsor may submit data from the clinical trial to the FDA in support of a BLA or IND application so long as the clinical trial is conducted in compliance with GCP, and the FDA is able to validate the data from the study through an onsite inspection if the agency deems it necessary. A separate submission to the existing IND application must be made for each successive clinical trial to be conducted during product development. Further, an independent Institutional Review Board, or IRB, for each site at which the clinical trial will be conducted must review and approve the clinical trial before it commences at that site. Informed written consent must also be obtained from each trial subject. Regulatory authorities, including the FDA, or IRB, or the sponsor, may suspend or terminate a clinical trial at any time on various grounds, including a finding that the participants are being exposed to an unacceptable health risk or that the clinical trial is not being conducted in accordance with FDA requirements. Additionally, some clinical trials are overseen by an independent group of qualified experts organized by the clinical trial sponsor, known as a data safety monitoring board or committee. This group provides authorization as to whether or not a trial may move forward at designated check points based on access to certain data from the trial and may recommend halting the clinical trial if it determines that there is an unacceptable safety risk for subjects or other grounds, such as no demonstration of efficacy. Human clinical trials for BLA approval typically involve a three-phase process, although some phases may overlap or be combined. Phase 1, the initial clinical evaluations, consists of administering the drug and testing for safety and tolerated dosages and in some indications such as rare disease, as preliminary evidence of efficacy in humans. Phase 2 involves a study to evaluate the effectiveness of the drug for a particular indication and to determine optimal dosage and dose interval and to identify possible adverse side effects and risks in a larger patient group. When a product is found safe, and initial efficacy is established in Phase 2, it is then evaluated in Phase 3 clinical trials. Phase 3 trials consist of expanded multi-location testing for efficacy and safety to evaluate the overall benefit-to-risk index of the investigational drug in relationship to the disease treated. The results of preclinical and human clinical testing are submitted to the FDA in the form of a BLA for approval to commence commercial sales. All clinical trials must be conducted in accordance with FDA regulations, GCP requirements and their protocols in order for the data to be considered reliable for regulatory purposes. Progress reports detailing the results of the clinical trials must be submitted at least annually to the FDA and more frequently if serious adverse events occur. Phase 1, Phase 2 and Phase 3 clinical trials may not be completed successfully within any specified period, or at all. Government regulation may delay or prevent marketing of product candidates or new drugs for a considerable period of time and impose costly procedures upon our activities. Disclosure of Clinical Trial Information Sponsors of clinical trials of FDA-regulated products, including drugs, are required to register and disclose certain clinical trial information. Information related to the product, patient population, phase of investigation, study sites and investigators, and other aspects of the clinical trial is then made public as part of the registration. Sponsors are also obligated to disclose the results of their clinical trials after completion. Disclosure of the results of these trials can be delayed until the new product or new indication being studied has been approved up to a maximum of two years. Competitors may use this publicly available information to gain knowledge regarding the progress of development programs. The BLA Approval Process In order to obtain approval to market a drug in the U.S., a marketing application must be submitted to the FDA that provides data establishing to the FDA’s satisfaction the safety and effectiveness of the investigational drug for the proposed indication. The application includes all relevant data available from pertinent non-clinical or preclinical studies and clinical trials, including negative or ambiguous 39 Table of Contents results as well as positive findings, together with detailed information relating to the product’s chemistry, manufacturing, controls and proposed labeling, among other things. Data can come from company-sponsored clinical trials intended to test the safety and effectiveness of a use of a product, or from a number of alternative sources, including studies initiated by investigators that meet GCP requirements. During the development of a new drug, sponsors are given opportunities to meet with the FDA at certain points. These points may be prior to submission of an IND application, at the End-of-Phase 1 or 2, and before a BLA is submitted. Meetings at other times may be requested. These meetings can provide an opportunity for the sponsor to share information about the data gathered to date, for the FDA to provide advice and for the sponsor and the FDA to reach agreement on the next phase of development. The results of product development, non-clinical studies and clinical trials, along with descriptions of the manufacturing process, analytical tests conducted on the chemistry of the drug, proposed labeling and other relevant information are submitted to the FDA as part of a BLA requesting approval to market the product for its intended indication. The FDA reviews all BLAs submitted to ensure that they are sufficiently complete for substantive review before it accepts them for filing. It may request additional information rather than accept a BLA for filing. In this event, the BLA must be resubmitted with the additional requested information. The resubmitted application also is subject to review before the FDA accepts it for filing. The FDA has 60 days from its receipt of a BLA to conduct an initial review to determine whether the application will be accepted for filing based on the agency’s threshold determination that the application is sufficiently complete to permit substantive review. The FDA reviews a BLA to determine, among other things, whether the proposed product is safe and potent, or effective, for its intended use, and has an acceptable purity profile, and whether the product is being manufactured in accordance with cGMP to assure and preserve the product’s identity, safety, strength, quality, potency and purity. The FDA has agreed to specific performance goals on the review of BLA’s. Specifically, under the goals and policies agreed to by the FDA under the Prescription Drug User Fee Act, or PDUFA, as amended, the FDA has 10 months, from the filing date, in which to complete its initial review of an original BLA and respond to the applicant, and six months from the filing date of an original BLA designated for priority review. The review process may be extended by the FDA for three additional months to consider certain late-submitted information or information intended to clarify information already provided in the submission. After the FDA completes its substantive review of a BLA, it will communicate to the sponsor that the drug will either be approved, or it will issue a complete response letter to communicate that the BLA will not be approved in its current form and inform the sponsor of changes that must be made or additional clinical, non-clinical or manufacturing data that must be received before the application can be approved, with no implication regarding the ultimate approvability of the application or the timing of any such approval, if ever. If or when those deficiencies have been addressed to the FDA’s satisfaction in a resubmission of the BLA, the FDA may issue an approval letter. The FDA has committed to reviewing such resubmissions in two to six months depending on the type of information included. The FDA may refer applications for novel drug products or drug products that present difficult questions of safety or efficacy to an advisory committee, typically a panel that includes clinicians and other experts, for review, evaluation, and a recommendation as to whether the application should be approved and, if so, under what conditions. The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions. Before approving a BLA, the FDA typically will inspect the facilities at which the product is manufactured. The FDA will not approve the product unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and are adequate to assure consistent production of the product within required specifications. Additionally, before approving a BLA, the FDA may inspect one or more clinical sites to assure compliance with GCP. For a gene therapy product, the FDA also will not approve the product if the manufacturer is not in compliance with cGTPs. These are FDA regulations that govern the methods used in, and the facilities and controls used for, the manufacture of human cells, tissues, and cellular and tissue-based products, or HCT/Ps, which are human cells or tissue intended for implantation, transplant, infusion, or transfer into a human recipient. The primary intent of the cGTP requirements is to ensure that cell and tissue-based products are manufactured in a manner designed to prevent the introduction, transmission and spread of communicable disease. FDA regulations also require tissue establishments to register and list their HCT/Ps with the FDA and, when applicable, to evaluate donors through appropriate screening and testing. If the FDA determines that the application, manufacturing process or manufacturing facilities are not acceptable, it typically will outline the deficiencies and often will request additional testing or information. This may significantly delay further review of the application. If the FDA finds that a clinical site did not conduct the clinical trial in accordance with GCP, the FDA may determine the data generated by the clinical site should be excluded from the primary efficacy analyses provided in the BLA. Additionally, notwithstanding the submission of any requested additional information, the FDA ultimately may decide that the application does not satisfy the regulatory criteria for approval. The FDA may require, or companies may pursue, additional clinical trials after a product is approved. These so-called Phase 4 or post-approval trials may be made a condition to be satisfied for continuing drug approval. The results of Phase 4 trials can confirm the effectiveness of a product candidate and can provide important safety information. In addition, the FDA has authority to require sponsors to conduct post-marketing trials to specifically address safety issues identified by the agency. See “Post-Marketing Requirements” below. 40 Table of Contents The FDA also has authority to require a Risk Evaluation and Mitigation Strategy, or REMS, from manufacturers to ensure that the benefits of a drug outweigh its risks. A sponsor may also voluntarily propose a REMS as part of the BLA submission. The need for a REMS is determined as part of the review of the BLA. Based on statutory standards, elements of a REMS may include “Dear Doctor letters,” a medication guide, more elaborate targeted educational programs, and in some cases distribution and use restrictions, referred to as elements to assure safe use, or ETASU. ETASU can include, but are not limited to, special training or certification for prescribing or dispensing, dispensing only under certain circumstances, special monitoring and the use of patient registries. These elements are negotiated as part of the BLA approval, and in some cases the approval date may be delayed. Once adopted, REMS are subject to periodic assessment and modification. Changes to some of the conditions established in an approved application, including changes in indications, labeling, manufacturing processes or facilities, require submission and FDA approval of a new BLA or BLA supplement before the change can be implemented. A BLA supplement for a new indication typically requires clinical data similar to that in the original application, and the FDA uses the same procedures and actions in reviewing BLA supplements as it does in reviewing BLAs. Even if a product candidate receives regulatory approval, the approval may be limited to specific disease states, patient populations and dosages, or might contain significant limitations on use in the form of warnings, precautions or contraindications, or in the form of onerous risk management plans, restrictions on distribution or use, or post-marketing trial requirements. Further, even after regulatory approval is obtained, later discovery of previously unknown problems with a product may result in restrictions on the product, including safety labeling or imposition of a REMS, the requirement to conduct post-market studies or clinical trials or even complete withdrawal of the product from the market. Delay in obtaining, or failure to obtain, regulatory approval for our products, or obtaining approval but for significantly limited use, would harm our business. In addition, we cannot predict what adverse governmental regulations may arise from future U.S. or foreign governmental action. The Hatch-Waxman Amendments Under the Drug Price Competition and Patent Term Restoration Act of 1984, referred to as the Hatch-Waxman Amendments, a portion of a product’s U.S. patent term that was lost during clinical development and regulatory review by the FDA may be restored by returning up to five years of patent life for a patent that covers a new product or its use. This period is generally one-half the time between the effective date of an IND application (falling after issuance of the patent) and the submission date of a BLA, plus the time between the submission date of a BLA and the approval of that application, provided that the sponsor acted with diligence. Patent term restorations, however, cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval and only one patent applicable to an approved drug may be extended and the extension must be applied for prior to expiration of the patent. The U.S. Patent and Trademark Office, in consultation with the FDA, reviews and approves the application for any patent term extension or restoration. Market Exclusivity The Patient Protection and Affordable Care Act, as amended by the Health Care Education and Reconciliation Act, or, collectively, the ACA, signed into law on March 23, 2010, includes a subtitle called the Biologics Price Competition and Innovation Act of 2009, or the BPCIA, which created an abbreviated approval pathway for biological products shown to be similar to, or interchangeable with, an FDA-approved reference biological product. Bio similarity, which requires that there be no clinically meaningful differences between the biological product and the reference product in terms of safety, purity, and potency, can be shown through analytical studies, animal studies, and a clinical trial or trials. Interchangeability requires that a product is biosimilar to the reference product and the product must demonstrate that it can be expected to produce the same clinical results as the reference product and, for products administered multiple times, the biologic and the reference biologic may be switched after one has been previously administered without increasing safety risks or risks of diminished efficacy relative to exclusive use of the reference biologic. However, complexities associated with the larger, and often more complex, structure of biological products, as well as the process by which such products are manufactured, pose significant hurdles to implementation that are still being worked out by the FDA. A reference biological product is granted four- and 12-year exclusivity periods from the time of first licensure of the product. FDA will not accept an application for a biosimilar or interchangeable product based on the reference biological product until four years after the date of first licensure of the reference product, and FDA will not approve an application for a biosimilar or interchangeable product based on the reference biological product until 12 years after the date of first licensure of the reference product. “First licensure” typically means the initial date the particular product at issue was approved in the U.S. Date of first licensure does not include the date of licensure of (and a new period of exclusivity is not available for) a biological product if the licensure is for a supplement for the biological product or for a subsequent application by the same sponsor or manufacturer of the biological product (or licensor, predecessor in interest, or other related entity) for a change (not including a modification to the structure of the biological product) that results in a new indication, route of administration, dosing schedule, dosage form, delivery system, delivery device or strength, or for a modification 41 Table of Contents to the structure of the biological product that does not result in a change in safety, purity, or potency. Therefore, one must determine whether a new product includes a modification to the structure of a previously approved product that results in a change in safety, purity, or potency to assess whether the licensure of the new product is a first licensure that triggers its own period of exclusivity. Whether a subsequent application, if approved, warrants exclusivity as the “first licensure” of a biological product is determined on a case-by-case basis with data submitted by the sponsor. In addition, under the Orphan Drug Act, the FDA may designate a biologic product as an “orphan drug” if it is intended to treat a rare disease or condition (generally meaning that it affects fewer than 200,000 individuals in the U.S., or more in cases in which there is no reasonable expectation that the cost of developing and making a biologic product available in the U.S. for treatment of the disease or condition will be recovered from sales of the product). Orphan product designation must be requested before submitting a BLA. After FDA grants orphan product designation, the identity of the therapeutic agent and its potential orphan use are disclosed publicly by FDA. Orphan product designation does not convey any advantage in, or shorten the duration of, the regulatory review and approval process. If a product with orphan status receives the first FDA approval for the disease or condition for which it has such designation, the product is entitled to orphan product exclusivity, meaning that the FDA may not approve any other applications to market the same drug or biologic product for the same indication for seven years, except in limited circumstances, such as a showing of clinical superiority to the product with orphan exclusivity or if the party holding the exclusivity fails to assure the availability of sufficient quantities of the drug to meet the needs of patients with the disease or condition for which the drug was designated. Competitors, however, may receive approval of different products for the same indication than that for which the orphan product has exclusivity or obtain approval for the same product but for a different indication for which the orphan product has exclusivity. Orphan medicinal product status in the EU has similar, but not identical, benefits. Pediatric exclusivity is another type of non-patent marketing exclusivity in the U.S. and, if granted, provides for the attachment of an additional six months to existing exclusivity periods for all formulations, dosage forms, and indications of the biologic. This six-month exclusivity may be granted if a BLA sponsor submits pediatric data that fairly respond to a written request from the FDA for such data. Rare Pediatric Disease Designation and Priority Review Vouchers Under the FDCA, the FDA incentivizes the development of drugs and biological products that meet the definition of a “rare pediatric disease,” defined to mean a serious or life-threatening disease in which the serious of life-threatening manifestations primarily affect individuals aged from birth to 18 years and the disease affects fewer than 200,000 individuals in the U.S. or affects more than 200,000 in the U.S. and for which there is no reasonable expectation that the cost of developing and making in the U.S. a drug or biological product for such disease or condition will be received from sales in the U.S. of such drug or biological product. The sponsor of a product candidate for a rare pediatric disease may be eligible for a voucher that can be used to obtain a priority review for a subsequent human drug or biological product application after the date of approval of the rare pediatric disease drug or biological product, referred to as a priority review voucher, or PRV. A sponsor may request rare pediatric disease designation from the FDA prior to the submission of its BLA. A rare pediatric disease designation does not guarantee that a sponsor will receive a PRV upon approval of its BLA. Moreover, a sponsor who chooses not to submit a rare pediatric disease designation request may nonetheless receive a PRV upon approval of their marketing application if they request such a voucher in their original marketing application and meet all of the eligibility criteria. If a PRV is received, it may be sold or transferred an unlimited number of times. Congress has extended the PRV program through September 30, 2024, with the potential for PRVs to be granted through September 30, 2026. Expedited Development and Review Programs The FDA is authorized to expedite the review of BLAs in several ways. Under the Fast Track program, the sponsor of a biologic product candidate may request the FDA to designate the product for a specific indication as a Fast Track product concurrent with or after the filing of the IND application. Biologic products are eligible for Fast Track designation if they are intended to treat a serious or life-threatening condition and demonstrate the potential to address unmet medical needs for the condition. Fast Track designation applies to the combination of the product candidate and the specific indication for which it is being studied. In addition to other benefits, such as the ability to have greater interactions with the FDA, the FDA may initiate review of sections of a Fast Track BLA before the application is complete, a process known as rolling review. Any product submitted to the FDA for marketing, including under a Fast Track program, may be eligible for other types of FDA programs intended to expedite development and review, such as regenerative medicine advanced therapy, or RMAT, designation, priority review and accelerated approval. To qualify for RMAT designation, the product candidate must be a regenerative medicine therapy, which is defined as a cell therapy, therapeutic tissue engineering product, human cell and tissue product, or any combination product using such therapies or products, except for those regulated solely under Section 361 of the Public Health Service Act and part 1271 of Title 21 of the Code of Federal Regulations; is intended to treat, modify, reverse, or cure a serious or life-threatening disease or 42 Table of Contents condition; and preliminary clinical evidence indicates that the product has the potential to address unmet medical needs for such disease or condition. A gene therapy product may meet the definition of a regenerative medicine therapy for purposes of RMAT designation. A BLA for a product candidate that has received RMAT designation may be eligible for priority review or accelerated approval through use of surrogate or intermediate endpoints reasonably likely to predict long-term clinical benefit, or reliance upon data obtained from a meaningful number of sites. Benefits of RMAT designation also include early interactions with the FDA to discuss any potential surrogate or intermediate endpoint to be used to support accelerated approval. A product candidate with RMAT designation that is granted accelerated approval and is subject to post-approval requirements may fulfill such requirements through the submission of clinical evidence from clinical studies, patient registries, or other sources of real-world evidence, such as electronic health records; the collection of larger confirmatory data sets; or post-approval monitoring of all patients treated with such therapy prior to its approval. A product candidate including one that received Fast Track or RMAT designation is eligible for priority review if it treats a serious condition and, if approved, it would be a significant improvement in the safety or effectiveness of the treatment, diagnosis or prevention of a serious condition compared to available therapies. The FDA aims to complete its review of priority review applications within six months of the filing date, compared to 10 months for standard review. Additionally, a biologic product may be eligible for accelerated approval if it is designed to treat a serious or life-threatening disease or condition and demonstrates an effect on a surrogate endpoint that is reasonably likely to predict a clinical benefit, or on the basis of an effect on a clinical endpoint other than survival or irreversible morbidity or mortality or other clinical benefit, taking into account the severity, rarity and prevalence of the condition and the availability or lack of alternative treatments. As a condition of approval, the FDA may require that a sponsor of a drug or biologic product candidate receiving accelerated approval perform adequate and well-controlled post-marketing clinical trials and, under the Food and Drug Omnibus Reform Act of 2022, or FDORA, the FDA is now permitted to require, as appropriate, that such trials be underway prior to approval or within a specific time period after the date of approval for a product granted accelerated approval. Under FDORA, the FDA has increased authority for expedited procedures to withdraw approval of a drug or indication approved under accelerated approval if, for example, the confirmatory trial fails to verify the predicted clinical benefit of the product. In addition, the FDA currently requires, unless otherwise informed by the agency, pre-approval of promotional materials intended for dissemination or publication . Even if a product qualifies for one or more of these programs, the FDA may later decide that the product no longer meets the conditions for qualification or the time period for FDA review or approval may not be shortened. Fast Track designation, priority review and accelerated approval do not change the standards for approval but may expedite the development or approval process. Additionally, under FDORA, a platform technology incorporated within or utilized by a biological product is eligible for designation as a designated platform technology if (1) the platform technology is incorporated in, or utilized by, a biological product approved under a BLA; (2) preliminary evidence submitted by the sponsor of the licensed biological product, or a sponsor that has been granted a right of reference to data submitted in the application for such biological product, demonstrates that the platform technology has the potential to be incorporated in, or utilized by, more than one biological product without an adverse effect on quality, manufacturing, or safety; and (3) data or information submitted by the applicable person indicates that incorporation or utilization of the platform technology has a reasonable likelihood to bring significant efficiencies to the biological product development or manufacturing process and to the review process. A sponsor may request the FDA to designate a platform technology as a designated platform technology concurrently with, or at any time after, submission of an IND application for a biological product that incorporates or utilizes the platform technology that is the subject of the request. If so designated, the FDA may expedite the development and review of any subsequent original BLA for a biological product that uses or incorporates the platform technology. Designated platform technology status does not ensure that a biological product will be developed more quickly or receive FDA approval. In addition, the FDA may revoke a designation if the FDA determines that a designated platform technology no longer meets the criteria for such designation. Post-Marketing Requirements Following approval of a new product, a pharmaceutical company and the approved product are subject to continuing regulation by the FDA, including, among other things, monitoring and recordkeeping activities, reporting to the applicable regulatory authorities of adverse experiences with the product, providing the regulatory authorities with updated safety and efficacy information, product sampling and distribution requirements, and complying with promotion and advertising requirements, which include, among others, standards for direct-to-consumer advertising, restrictions on promoting drugs for uses or in patient populations that are not described in the drug’s approved labeling, or off-label use, limitations on industry-sponsored scientific and educational activities and requirements for promotional activities involving the internet. Although physicians may, in their independent professional medical judgment, prescribe legally available drugs for off-label uses, manufacturers typically may not market or promote such off-label uses. Modifications or enhancements to the product or its labeling or changes of the site of manufacture are often subject to the approval of the FDA and other regulators, who may or may not grant approval or may include a lengthy review process. 43 Table of Contents Prescription drug advertising is subject to federal, state, and foreign regulations. In the U.S., the FDA regulates prescription drug promotion, including direct-to-consumer advertising. Prescription drug promotional materials must be submitted to the FDA in conjunction with their first use. Any distribution of prescription drug products and pharmaceutical samples must comply with the U.S. Prescription Drug Marketing Act, a part of the FDCA. In the U.S., once a product is approved, its manufacturing is subject to comprehensive and continuing regulation by the FDA. The FDA regulations require that products be manufactured in specific approved facilities and in accordance with cGMP. cGMP regulations require among other things, quality control and quality assurance as well as the corresponding maintenance of records and documentation and the obligation to investigate and correct any deviations from cGMP. Drug manufacturers and other entities involved in the manufacture and distribution of approved drugs are required to register their establishments with the FDA and certain state agencies and are subject to periodic unannounced inspections by the FDA and certain state agencies for compliance with cGMP and other laws. Additionally, manufacturers and other parties involved in the supply chain for prescription drug products must also comply with product tracking and racing requirements and for notifying the FDA of counterfeit, diverted, stolen and intentionally adulterated products or products that are otherwise unfit for distribution in the U.S. Accordingly, manufacturers must continue to expend time, money, and effort in the area of production and quality control to maintain cGMP compliance. These regulations also impose certain organizational, procedural and documentation requirements with respect to manufacturing and quality assurance activities. BLA holders using contract manufacturers, laboratories or packagers are responsible for the selection and monitoring of qualified firms, and, in certain circumstances, qualified suppliers to these firms. These firms and, where applicable, their suppliers are subject to inspections by the FDA at any time, and the discovery of violative conditions, including failure to conform to cGMP, could result in enforcement actions that interrupt the operation of any such product or may result in restrictions on a product, manufacturer, or holder of an approved BLA, including, among other things, recall or withdrawal of the product from the market. In addition, the manufacturer and/or holder of an approved BLA are subject to annual product and establishment fees. These fees are typically increased annually. The FDA also may require post-marketing testing, also known as Phase 4 testing, to monitor the effects of an approved product or place conditions on an approval via a REMS that could restrict the distribution or use of the product. Discovery of previously unknown problems with a product or the failure to comply with applicable FDA requirements can have negative consequences, including adverse publicity, judicial or administrative enforcement, untitled or warning letters from the FDA, mandated corrective advertising or communications with doctors, withdrawal of approval, and civil or criminal penalties, among others. Newly discovered or developed safety or effectiveness data may require changes to a product’s approved labeling, including the addition of new warnings and contraindications, and also may require the implementation of other risk management measures. Also, new government requirements, including those resulting from new legislation, may be established, or the FDA’s policies may change, which could delay or prevent regulatory approval of our products under development. Coverage and Reimbursement Sales of any products for which we receive regulatory approval for commercial sale will depend in part on the availability of reimbursement from third-party payors, including government healthcare program administrative authorities, managed care organizations, private health insurers, and other entities. Patients who are prescribed medications for the treatment of their conditions, and their prescribing physicians, generally rely on third-party payors to reimburse all or part of the costs associated with their prescription drugs. Patients are unlikely to use our products unless coverage is provided, and reimbursement is adequate to cover a significant portion of the cost of our products. Therefore, our products, once approved, may not obtain market acceptance unless coverage is provided, and reimbursement is adequate to cover a significant portion of the cost of our products. In the U.S., no uniform policy of coverage and reimbursement for drug or biological products exists. The process for determining whether a third-party payor will provide coverage for a drug product typically is separate from the process for setting the price of a drug product or for establishing the reimbursement rate that the payor will pay for the drug product once coverage is approved. Third-party payors may limit coverage to specific drug products on an approved list, also known as a formulary, which might not include all of the FDA-approved drugs for a particular indication. A decision by a third-party payor not to cover our product candidates could reduce physician utilization of our products once approved. Moreover, a third-party payor’s decision to provide coverage for a drug product does not imply that an adequate reimbursement rate will be approved. Adequate third-party reimbursement may not be available to enable us to maintain price levels sufficient to realize an appropriate return on our investment in product development. Additionally, coverage and reimbursement for drug products can differ significantly from payor to payor. One third-party payor’s decision to cover a particular drug product or service does not ensure that other payors will also provide coverage for the medical product or service or will provide coverage at an adequate reimbursement rate. As a result, the coverage determination process will require us to provide scientific and clinical support for the use of our products to each payor separately and will be a time-consuming process. The containment of healthcare costs has become a priority of federal, state, and foreign governments, and the prices of drugs have been a focus in this effort. Third-party payors are increasingly challenging the prices charged for drug products and medical services, examining the medical necessity, and reviewing the cost effectiveness of drug products and medical services, in addition to questioning 44 Table of Contents safety and efficacy. If these third-party payors do not consider our products to be cost-effective compared to other available therapies, they may not cover our products after FDA approval or, if they do, the level of payment may not be sufficient to allow us to sell our products at a profit. The American Recovery and Reinvestment Act of 2009 provided funding for the federal government to compare the effectiveness of different treatments for the same illness. The plan for the research was published in 2012 by the Department of Health and Human Services, the Agency for Healthcare Research and Quality and the National Institutes for Health, and periodic reports on the status of the research and related expenditures will be made to Congress. Although the results of the comparative effectiveness studies are not intended to mandate coverage policies for public or private payors, it is not clear what effect, if any, the research will have on the sales of our product candidates, if any such product or the condition that it is intended to treat is the subject of a study. It is also possible that comparative effectiveness research demonstrating benefits in a competitor’s product could adversely affect the sales of our product candidates, once approved. If third-party payors do not consider our products to be cost-effective compared to other available therapies, they may not cover our products after approval as a benefit under their plans or, if they do, the level of payment may not be sufficient to allow us to sell our products on a profitable basis. In addition, in some foreign countries, the proposed pricing for a drug must be approved before it may be lawfully marketed. The requirements governing drug pricing vary widely from country to country. For example, the EU provides options for its member states to restrict the range of medicinal products for which their national health insurance systems provide reimbursement and to control the prices of medicinal products for human use. A member state may approve a specific price for the medicinal product, or it may instead adopt a system of direct or indirect controls on the profitability of the company placing the medicinal product on the market. There can be no assurance that any country that has price controls or reimbursement limitations for pharmaceutical products will allow favorable reimbursement and pricing arrangements for any of our products. Historically, products launched in the EU do not follow price structures of the U.S. and generally tend to be significantly lower. Anti-Kickback and False Claims Laws and Other Regulatory Matters In the U.S., among other things, the research, manufacturing, distribution, sale and promotion of drug products and medical devices are potentially subject to regulation and enforcement by various federal, state and local authorities in addition to the FDA, including the Centers for Medicare & Medicaid Services, other divisions of the U.S. Department of Health and Human Services (HHS) (e.g., the Office of Inspector General), the Drug Enforcement Administration, the Consumer Product Safety Commission, the Federal Trade Commission, the Occupational Safety & Health Administration, the Environmental Protection Agency, state Attorneys General and other state and local government agencies. Our current and future business activities, including for example, sales, marketing, and scientific/educational grant programs must comply with healthcare regulatory laws, as applicable, which may include the Federal Anti-Kickback Statute, the Federal False Claims Act, as amended, the privacy and security regulations promulgated under the Health Insurance Portability and Accountability Act, or HIPAA, as amended, physician payment transparency laws, and similar state laws. Pricing and rebate programs must comply with the Medicaid Drug Rebate Program requirements of the Omnibus Budget Reconciliation Act of 1990, as amended, and the Veterans Health Care Act of 1992, as amended. If products are made available to authorized users of the Federal Supply Schedule of the General Services Administration, additional laws and requirements apply. All of these activities are also potentially subject to federal and state consumer protection and unfair competition laws. The distribution of pharmaceutical products is subject to additional requirements and regulations, including extensive record-keeping, licensing, storage, and security requirements intended to prevent the unauthorized sale of pharmaceutical products. The Federal Anti-Kickback Statute makes it illegal for any person or entity, including a prescription drug manufacturer (or a party acting on its behalf) to knowingly and willfully, directly or indirectly, in cash or in kind, solicit, receive, offer, or pay any remuneration that is intended to induce the referral of business, including the purchasing, leasing, ordering or arranging for or recommending the purchase, lease or order of, any good, facility, item or service for which payment may be made, in whole or in part, under a federal healthcare program, such as Medicare or Medicaid. The term “remuneration” has been broadly interpreted to include anything of value. The Federal Anti-Kickback Statute has been interpreted to apply to arrangements between pharmaceutical manufacturers on one hand and prescribers, purchasers, and formulary managers on the other. Although there are a number of statutory exceptions and regulatory safe harbors protecting some common activities from prosecution, the exceptions and safe harbors are drawn narrowly. Practices that involve remuneration that may be alleged to be intended to induce prescribing, purchases or recommendations may be subject to scrutiny if they do not qualify for an exception or safe harbor. Failure to meet all of the requirements of a particular applicable statutory exception or regulatory safe harbor does not make the conduct per se illegal under the Federal Anti-Kickback Statute. Instead, the legality of the arrangement will be evaluated on a case-by-case basis based on a cumulative review of all of its facts and circumstances. Additionally, the intent standard under the Federal Anti-Kickback Statute was amended by the ACA to a stricter standard such that a person or entity no longer needs to have actual knowledge of the statute or specific intent to violate it in order to have committed a violation. In addition, the ACA codified case law that a claim including items or services resulting from a violation of the Federal Anti-Kickback Statute 45 Table of Contents constitutes a false or fraudulent claim for purposes of the Federal False Claims Act. Violations of this law are punishable by up to five years in prison, criminal fines, administrative civil money penalties, and exclusion from participation in federal healthcare programs. In addition, many states have adopted laws similar to the Federal Anti-Kickback Statute. Some of these state prohibitions apply to the referral of patients for healthcare services reimbursed by any insurer, not just federal healthcare programs such as Medicare and Medicaid. Due to the breadth of these federal and state anti-kickback laws, and the potential for additional legal or regulatory change in this area, it is possible that our future business activities, including our sales and marketing practices and/or our future relationships with physicians and the medical community might be challenged under anti-kickback laws, which could harm us. Federal false claims and false statement laws, including the civil False Claims Act, prohibits any person or entity from, among other things, knowingly presenting, or causing to be presented, for payment to federal programs (including Medicare and Medicaid) claims for items or services, including drugs, that are false or fraudulent. Although we would not submit claims directly to payors, manufacturers can be held liable under these laws if they are deemed to “cause” the submission of false or fraudulent claims by, for example, providing inaccurate billing or coding information to customers or promoting a product off-label. In addition, our future activities relating to the reporting of wholesaler or estimated retail prices for our products, the reporting of prices used to calculate Medicaid rebate information and other information affecting federal, state, and third-party reimbursement for our products, and the sale and marketing of our products, are subject to scrutiny under this law. For example, pharmaceutical companies have been found liable under the Federal Civil False Claims Act in connection with their off-label promotion of drugs. Penalties for a civil False Claims Act violation include three times the actual damages sustained by the government, plus mandatory civil penalties for each separate false claim, the potential for exclusion from participation in federal healthcare programs, and, although the Federal False Claims Act is a civil statute, conduct that results in a False Claims Act violation may also implicate various federal criminal statutes. If the government were to allege that we were, or convict us of, violating these false claims laws, we could be subject to a substantial fine and may suffer a decline in our stock price. In addition, private individuals have the ability to bring actions under the Federal Civil False Claims Act and certain states have enacted laws modeled after the Federal False Claims Act. Additionally, HIPAA created additional federal criminal statutes that prohibit, among other things, knowingly and willfully executing, or attempting to execute, a scheme to defraud any healthcare benefit program, including private third-party payors and knowingly and willfully falsifying, concealing, or covering up a material fact or making any materially false, fictitious, or fraudulent statement in connection with the delivery of or payment for healthcare benefits, items or services. Similar to the federal Anti-Kickback Statute, a person or entity does not need to have actual knowledge of the statute or specific intent to violate it in order to have committed a violation. There are also an increasing number of state laws that require manufacturers to make reports to states on pricing and marketing information. Many of these laws contain ambiguities as to what is required to comply with the laws. For example, federal government price reporting laws, which require us to calculate and report complex pricing metrics in an accurate and timely manner to government programs. In addition, as discussed below, a similar federal requirement under the Physician Payments Sunshine Act, requires certain manufacturers to track and report to the federal government certain payments provided to physicians, certain other licensed health care practitioners and teaching hospitals made in the previous calendar year, as well as certain ownership and investment interests held by physicians (defined to include doctors, dentists, optometrists, podiatrists, and chiropractors) and their immediate family members. These laws may affect our sales, marketing, and other promotional activities by imposing administrative and compliance burdens on us. In addition, given the lack of clarity with respect to these laws and their implementation, our reporting actions could be subject to the penalty provisions of the pertinent state and federal authorities. Further, we may be subject to data privacy and security regulation by both the federal government and the states in which we conduct our business. HIPAA, as amended by the Health Information Technology for Economic and Clinical Health Act, or HITECH, and their respective implementing regulations, including the Final Omnibus Rule published on January 25, 2013, imposes specified requirements relating to the privacy, security, and transmission of individually identifiable health information on certain types of individuals and organizations. HITECH also created new tiers of civil monetary penalties, amended HIPAA to make civil and criminal penalties directly applicable to business associates, and gave state attorneys general new authority to file civil actions for damages or injunctions in federal courts to enforce the federal HIPAA laws and seek attorneys’ fees and costs associated with pursuing federal civil actions. In addition, there may be other federal, state and non-U.S. laws which govern the privacy and security of health and other personal information in certain circumstances, many of which differ from each other and from HIPAA in significant ways and may not have the same effect, thus complicating compliance efforts. The failure to comply with regulatory requirements subjects us to possible legal or regulatory action. Depending on the circumstances, failure to meet applicable regulatory requirements can result in significant criminal, civil and/or administrative penalties, damages, fines, disgorgement, exclusion from participation in federal healthcare programs, such as Medicare and Medicaid, injunctions, recall or seizure of products, total or partial suspension of production, denial or withdrawal of product approvals, refusal to allow us to enter into supply contracts, including government contracts, contractual damages, reputational harm, administrative burdens, diminished 46 Table of Contents profits and future earnings, and the curtailment or restructuring of our operations, any of which could adversely affect our ability to operate our business and our results of operations. We plan to develop a comprehensive compliance program that establishes internal controls to facilitate adherence to the law and program requirements to which we will or may become subject because we intend to commercialize products that could be reimbursed under a federal healthcare program and other governmental healthcare programs. Changes in law or the interpretation of existing law could impact our business in the future by requiring, for example: (i) changes to our manufacturing arrangements; (ii) additions or modifications to product labeling; (iii) the recall or discontinuation of our products; or (iv) additional record-keeping requirements. If any such changes were to be imposed, they could adversely affect the operation of our business. Healthcare Legislative Reform In both the U.S. and certain foreign jurisdictions, there have been a number of legislative and regulatory changes to the health care system that could impact our ability to sell our products profitably. In particular, in 2010, the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010, or collectively, the ACA, was enacted, which, among other things, subjected biologic products to potential competition by lower-cost biosimilars; increased the minimum Medicaid rebates owed by most manufacturers under the Medicaid Drug Rebate Program; extended the Medicaid Drug Rebate program to utilization of prescriptions of individuals enrolled in Medicaid managed care organizations; subjected manufacturers to new annual fees and taxes for certain branded prescription drugs; created a new Medicare Part D coverage gap discount program, in which manufacturers must agree to offer 70% point-of-sale discounts off negotiated prices of applicable brand drugs to eligible beneficiaries during their coverage gap period, as a condition for the manufacturer’s outpatient drugs to be covered under Medicare Part D; and provided incentives to programs that increase the federal government’s comparative effectiveness research. Other legislative changes have been proposed and adopted since the ACA was enacted. • The Budget Control Act of 2011, which, among other things, created measures for spending reductions by Congress. This includes aggregate reductions of Medicare payments to providers of 2% per fiscal year. Subsequent legislation extended the 2% reduction which remains in effect through 2031. Due to the Statutory Pay-As-You-Go Act of 2010, estimated budget deficit increases resulting from the American Rescue Plan Act of 2021, and subsequent legislation, Medicare payments to providers will be further reduced starting in 2025 absent further legislation. • The American Taxpayer Relief Act of 2012, among other things, reduced Medicare payments to several providers and increased the statute of limitations period for the government to recover overpayments to providers from three to five years. • On April 13, 2017, CMS published a final rule that gives states greater flexibility in setting benchmarks for insurers in the individual and small group marketplaces, which may have the effect of relaxing the essential health benefits required under the ACA for plans sold through such marketplaces. • On May 30, 2018, the Right to Try Act, was signed into law. The law, among other things, provides a federal framework for certain patients to access certain investigational new drug products that have completed a Phase 1 clinical trial and that are undergoing investigation for FDA approval. Under certain circumstances, eligible patients can seek treatment without enrolling in clinical trials and without obtaining FDA permission under the FDA expanded access program. There is no obligation for a pharmaceutical manufacturer to make its drug products available to eligible patients as a result of the Right to Try Act. • On May 23, 2019, CMS published a final rule to allow Medicare Advantage Plans the option of using step therapy for Part B drugs beginning January 1, 2020. There has been increasing legislative and enforcement interest in the U.S. with respect to specialty drug pricing practices. Specifically, there have been several recent U.S. Congressional inquiries and proposed federal and state legislation designed to, among other things, bring more transparency to drug pricing, reduce the cost of prescription drugs under Medicare, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for drugs. On the federal level, President Biden has issued multiple executive orders that have sought to reduce prescription drug costs. In February 2023, HHS also issued a proposal in response to an October 2022 executive order from President Biden that includes a proposed prescription drug pricing model that will test whether targeted Medicare payment adjustments will sufficiently incentivize manufacturers to complete confirmatory trials for drugs approved through the FDA’s accelerated approval pathway. Although a number of these and other proposed measures may require authorization through additional legislation to become effective, and the Biden administration 47 Table of Contents may reverse or otherwise change these measures, both the Biden administration and Congress have indicated that they will continue to seek new legislative measures to control drug costs. The Inflation Reduction Act of 2022 (IRA) includes several provisions that may impact our business to varying degrees, including provisions that reduce the out-of-pocket spending cap for Medicare Part D beneficiaries from $7,050 to $2,000 starting in 2025, thereby effectively eliminating the coverage gap; impose new manufacturer financial liability on certain drugs under Medicare Part D, allow the U.S. government to negotiate Medicare Part B and Part D price caps for certain high-cost drugs and biologics without generic or biosimilar competition; require companies to pay rebates to Medicare for certain drug prices that increase faster than inflation; and delay until January 1, 2032 the implementation of the HHS rebate rule that would have limited the fees that pharmacy benefit managers can charge. Further, under the IRA, orphan drugs are exempted from the Medicare drug price negotiation program, but only if they have one orphan designation and for which the only approved indication is for that disease or condition. If a product receives multiple orphan designations or has multiple approved indications, it may not qualify for the orphan drug exemption. The implementation of the IRA is currently subject to ongoing litigation challenging the constitutionality of the IRA’s Medicare drug price negotiation program. The outcome of these challenges on the IRA, and the effects of the IRA on our business and the healthcare industry in general are not yet known. At the state level, legislatures have increasingly passed legislation and implemented regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing. We expect that the healthcare reform measures that have been adopted and may be adopted in the future, may result in more rigorous coverage criteria and in additional downward pressure on the price that we receive for any approved product and could seriously harm our future revenues. Any reduction in reimbursement from Medicare or other government programs may result in a similar reduction in payments from private third-party payors. There have been, and likely will continue to be, legislative and regulatory proposals at the foreign, federal, and state levels directed at broadening the availability of healthcare and containing or lowering the cost of healthcare. The implementation of cost containment measures or other healthcare reforms may prevent us from being able to generate revenue, attain profitability, or commercialize our products. Such reforms could have an adverse effect on anticipated revenue from product candidates that we may successfully develop and for which we may obtain regulatory approval and may affect our overall financial condition and ability to develop product candidates. European Union Drug Review and Approval Clinical Trial Approval In the EU, an applicant for authorization of a clinical trial must obtain prior approval from the national competent authority of the EU Member States in which the clinical trial is to be conducted. Furthermore, the applicant may only start a clinical trial at a specific study site after the relevant independent ethics committee has issued a favorable opinion. In April 2014, the EU adopted the Clinical Trials Regulation (EU) No 536/2014, which replaced the Clinical Trials Directive 2001/20/EC on January 31, 2022. It overhauls the system of approvals for clinical trials in the EU. Specifically, the new legislation, which is directly applicable in all EU Member States (meaning that no national implementing legislation in each EU Member State is required), aims at simplifying and streamlining the approval of clinical trials in the EU. For instance, the Clinical Trials Regulation provides for a streamlined application procedure via a single-entry point (instead of submitting applications separately to each national competent authority and ethics committee in the Member States in which the trial will be conducted) and strictly defined deadlines for the assessment of clinical trial applications. The Clinical Trials Regulation also makes it more efficient for EU Member States to evaluate and authorize applications together, via the Clinical Trials Information System. The transitory provisions of the Clinical Trials Regulation provide that, by January 31, 2025, all ongoing clinical trials must have transitioned to the Clinical Trials Regulation. Marketing Authorization In the EU, medicinal products can only be commercialized after obtaining a marketing authorization. There are two types of marketing authorizations: (1) the centralized authorization, which is issued by the European Commission through the centralized procedure based on the opinion of the Committee for Medicinal Products for Human Use, or CHMP, a body of the EMA, and which is valid throughout the entire territory of the European Economic Area, or EEA (comprising the EU Member States plus Norway, Iceland and Liechtenstein); and (2) national marketing authorizations, which are issued by the competent authorities of the Member States of the EU and only authorize marketing in that Member State’s national territory and not the EEA as a whole. 48 Table of Contents The centralized procedure is mandatory for certain types of products, such as biotechnology medicinal products, orphan medicinal products, advanced therapy medicinal products (i.e., gene-therapy, somatic cell-therapy, and tissue-engineered medicines) and medicinal products containing a new active substance indicated for the treatment of HIV/AIDS, cancer, neurodegenerative disorders, diabetes, autoimmune disorders and other immune dysfunctions and viral diseases. The centralized procedure is optional for products containing a new active substance not yet authorized in the EU, or for products that constitute a significant therapeutic, scientific, or technical innovation or which are in the interest of public health in the EU. The EMA is responsible for the scientific evaluation of marketing authorization applications in the centralized procedure. The maximum timeframe for the evaluation of a marketing authorization application by the EMA is 210 days from receipt of a valid application, excluding clock stops when additional information or written or oral explanation is to be provided by the applicant in response to questions of the CHMP. Clock stops may extend the timeframe of evaluation of an application considerably beyond 210 days. Where the CHMP gives a positive opinion, the EMA provides the opinion together with supporting documentation to the European Commission, who makes the final decision to grant a marketing authorization, which is issued within 67 days of receipt of the EMA’s recommendation. Accelerated assessment may be granted by the CHMP in exceptional cases, when a medicinal product is of major interest from the point of view of public health and, in particular, from the viewpoint of therapeutic innovation. If the CHMP accepts such a request, the timeframe of 210 days for assessment will be reduced to 150 days (excluding clock stops), but it is possible that the CHMP may revert to the standard time limit for the centralized procedure if it determines that the application is no longer appropriate to conduct an accelerated assessment. National marketing authorizations are for products not falling within the mandatory scope of the centralized procedure. Where a product has already been authorized for marketing in a Member State of the EU, this marketing authorization can be recognized in another Member State through the mutual recognition procedure. If the product has not received a national marketing authorization in any Member State at the time of application, it can be approved simultaneously in various Member States through the decentralized procedure. Under the decentralized procedure an identical dossier is submitted to the competent authorities of each of the Member States in which an authorization is sought, one of which is selected by the applicant as the Reference Member State, or RMS. If the RMS proposes to authorize the product, and the other Member States do not raise objections, the product is granted a national marketing authorization in all the Member States where the authorization was sought. Under the above-described procedures, before granting the marketing authorization, the EMA or the competent authorities of the Member States of the EU make an assessment of the risk-benefit balance of the product on the basis of scientific criteria concerning its quality, safety, and efficacy. Now that the UK (which comprises Great Britain and Northern Ireland) has left the EU, Great Britain is no longer covered by centralized marketing authorizations (under the Northern Ireland Protocol, centralized marketing authorizations currently continue to be recognized in Northern Ireland). On January 1, 2024, a new international recognition framework was put in place by the Medicines and Healthcare products Regulatory Agency, or MHRA, the UK medicines regulator, under which the MHRA may have regard to decisions on the approval of marketing authorizations made by the EMA and certain other regulators when considering an application for a Great Britain marketing authorization. Regulatory exclusivity In the EU, innovative products authorized for marketing (i.e., reference products) may qualify for eight years of data exclusivity and an additional two years of market exclusivity upon marketing authorization. The data exclusivity period prevents generic or biosimilar applicants from relying on the preclinical and clinical trial data contained in the dossier of the reference product when applying for a generic or biosimilar marketing authorization in the EU during a period of eight years from the date on which the reference product was first authorized in the EU. The market exclusivity period prevents a successful generic or biosimilar applicant from commercializing its product in the EU until ten years have elapsed from the initial authorization of the reference product. The ten-year market exclusivity period can be extended to a maximum of 11 years if, during the first eight years of those ten years, the marketing authorization holder obtains an authorization for one or more new therapeutic indications which, during the scientific evaluation prior to their authorization, are held to bring a significant clinical benefit in comparison with existing therapies. Even if an innovative medicinal product gains the prescribed period of data exclusivity, however, another company may market another version of the product if such company obtained marketing authorization based on a marketing authorization application with a complete and independent data package of pharmaceutical tests, preclinical tests, and clinical trials. Orphan designation and exclusivity The criteria for designating an orphan medicinal product in the EU are similar in principle to those in the U.S. Under Regulation (EC) 141/2000, a medicinal product may be designated as an orphan product if the following criteria are fulfilled: (i) it is intended for the diagnosis, prevention or treatment of a life-threatening or chronically debilitating condition; (ii) either (a) such condition affects no 49 Table of Contents more than five in 10,000 persons in the EU when the application is made, or (b) the product, without the benefits derived from orphan status, would not generate sufficient return in the EU to justify the necessary investment in its development; and (iii) there exists no satisfactory method of diagnosis, prevention or treatment of such condition authorized for marketing in the EU, or if such a method exists, the product will be of significant benefit to those affected by the condition, as defined in Regulation (EC) 847/2000. Orphan medicinal products are eligible for financial incentives such as reduction of fees or fee waivers and are, upon grant of a marketing authorization, entitled to ten years of market exclusivity for the approved therapeutic indication. The application for orphan designation must be submitted before the application for marketing authorization. The applicant will receive a fee reduction for the marketing authorization application if the orphan designation has been granted, but not if the designation is still pending at the time the marketing authorization is submitted. Orphan designation does not convey any advantage in, or shorten the duration of, the regulatory review and approval process. The ten-year market exclusivity period may be reduced to six years if, at the end of the fifth year, it is established that the product no longer meets the criteria for orphan designation, for example, if the product is sufficiently profitable not to justify maintenance of market exclusivity. Otherwise, during the period of market exclusivity, a marketing authorization may only be granted in the EU to a “similar medicinal product” to the authorized orphan product for the same therapeutic indication if: • a second applicant can establish that its product, although similar to the authorized orphan product, is safer, more effective, or otherwise clinically superior; • the marketing authorization holder for the authorized orphan product consents to a second orphan medicinal product application; or • the marketing authorization holder for the authorized orphan product cannot supply enough orphan medicinal product. A “similar medicinal product” is defined as a medicinal product containing a similar active substance or substances as contained in an authorized orphan medicinal product, and which is intended for the same therapeutic indication. PRIME designation In March 2016, the EMA launched an initiative to facilitate development of product candidates in indications, often rare, for which few or no therapies currently exist. The PRIority MEdicines, or PRIME, scheme is intended to encourage product development in areas of unmet medical need and provides accelerated assessment of products representing substantial innovation, where the marketing authorization application will be made through the centralized procedure. Eligible products must target conditions for which there is an unmet medical need (i.e., there is no satisfactory method of diagnosis, prevention or treatment in the EU or, if there is, the new medicine will bring a major therapeutic advantage) and they must show potential to benefit patients with unmet medical needs based on early clinical data. Products from small- and medium-sized enterprises may qualify for earlier entry into the PRIME scheme than larger companies. Many benefits accrue to sponsors of product candidates with PRIME designation, including but not limited to, early and proactive regulatory dialogue with the EMA, frequent discussions on clinical trial designs and other development program elements, and accelerated marketing authorization application assessment once a dossier has been submitted. Importantly, a dedicated contact and rapporteur from the EMA’s CHMP or Committee for Advanced Therapies are appointed early in PRIME scheme facilitating increased understanding of the product at the EMA’s committee level. A kick-off meeting initiates these relationships and includes a team of multidisciplinary experts at the EMA to provide guidance on the overall development and regulatory strategies. Where, during the course of development, a medicine no longer meets the eligibility criteria, support under the PRIME scheme may be withdrawn. The aforementioned EU rules are generally applicable in the EEA. Reform of the Regulatory Framework in the European Union The European Commission introduced legislative proposals in April 2023 that, if implemented, will replace the current regulatory framework in the EU for all medicines (including those for rare diseases and for children). The European Commission has provided the legislative proposals to the European Parliament and the European Council for their review and approval. In October 2023, the European Parliament published draft reports proposing amendments to the legislative proposals, which will be debated by the European Parliament. Once the European Commission’s legislative proposals are approved (with or without amendment), they will be adopted into EU law. Brexit and the Regulatory Framework in the United Kingdom The UK formally left the EU on January 31, 2020, and the EU and the UK have concluded a trade and cooperation agreement, or TCA, which was provisionally applicable since January 1, 2021 and has been formally applicable since May 1, 2021. The TCA includes specific provisions concerning pharmaceuticals, which include the mutual recognition of GMP, inspections of manufacturing facilities 50 Table of Contents for medicinal products and GMP documents issued but does not provide for wholesale mutual recognition of UK and EU pharmaceutical regulations. At present, Great Britain has implemented EU legislation on the marketing, promotion and sale of medicinal products through the Human Medicines Regulations 2012 (as amended) (under the Northern Ireland Protocol, the EU regulatory framework currently continues to apply in Northern Ireland). The regulatory regime in Great Britain therefore largely aligns with current EU regulations, however it is possible that these regimes will diverge in the future now that Great Britain’s regulatory system is independent from the EU and the TCA does not provide for mutual recognition of UK and EU pharmaceutical legislation. For example, the EU Clinical Trials Regulation does not apply in the UK and the current UK clinical trials legislation is based on the now repealed Clinical Trials Directive 2001/20/EC. However, the MHRA published details of its legislative proposals designed to improve and strengthen the UK clinical trials legislation on March 21, 2023. The legislative proposals were published in response to a consultation which ran from January 17, 2022 to March 14, 2022. The MHRA will now work with lawyers to draft such new legislation. Notwithstanding that there is no wholesale recognition of EU pharmaceutical legislation under the TCA, under a new framework mentioned above which was put in place by the MHRA on January 1, 2024, the MHRA may take into account decisions on the approval of marketing authorizations from the EMA (and certain other regulators) when considering an application for a Great Britain marketing authorizations. On February 27, 2023, the UK government and the European Commission announced a political agreement in principle to replace the Northern Ireland Protocol with a new set of arrangements, known as the “Windsor Framework”. This new framework fundamentally changes the existing system under the Northern Ireland Protocol, including with respect to the regulation of medicinal products in the UK. In particular, the MHRA will be responsible for approving all medicinal products destined for the UK market (Great Britain and Northern Ireland), and the EMA will no longer have any role in approving medicinal products destined for Northern Ireland. A single UK-wide marketing authorization will be granted by the MHRA for all medicinal products to be sold in the UK, enabling products to be sold in a single pack and under a single authorization throughout the UK. The Windsor Framework was approved by the EU-UK Joint Committee on March 24, 2023, so the UK government and the EU will enact legislative measures to bring it into law. On June 9, 2023, the MHRA announced that the medicines aspects of the Windsor Framework will apply from January 1, 2025. The Foreign Corrupt Practices Act The Foreign Corrupt Practices Act, or the FCPA, prohibits any U.S. individual or business from paying, offering, or authorizing payment or offering of anything of value, directly or indirectly, to any foreign official, political party or candidate for the purpose of influencing any act or decision of the foreign entity in order to assist the individual or business in obtaining or retaining business. The FCPA also obligates companies whose securities are listed in the U.S. to comply with accounting provisions requiring us to maintain books and records that accurately and fairly reflect all transactions of the corporation, including international subsidiaries, and to devise and maintain an adequate system of internal accounting controls for international operations. Additional Regulation In addition to the foregoing, state and federal laws regarding environmental protection and hazardous substances, including the Occupational Safety and Health Act, the Resource Conservancy and Recovery Act and the Toxic Substances Control Act, affect our business. These and other laws govern our use, handling and disposal of various biological, chemical and radioactive substances used in, and wastes generated by, our operations. If our operations result in contamination of the environment or expose individuals to hazardous substances, we could be liable for damages and governmental fines. We believe that we are in material compliance with applicable environmental laws and that continued compliance therewith will not have a material adverse effect on our business. We cannot predict, however, how changes in these laws may affect our future operations. Other Regulations We are also subject to numerous federal, state and local laws relating to such matters as safe working conditions, manufacturing practices, environmental protection, fire hazard control, and disposal of hazardous or potentially hazardous substances. We may incur significant costs to comply with such laws and regulations now or in the future. Human Capital As of March 1, 2024, we had 154 full-time employees and 0 part-time employees, 39 of whom have Ph.D. or M.D. degrees. Of these full-time employees, 121 employees are engaged in research and development activities and 33 are engaged in finance, business development and other general and administrative functions. None of our employees are represented by labor unions or covered by collective bargaining agreements, and we have not experienced any work stoppages. We consider our relations with our employees to be good. 51 Table of Contents We recognize that attracting, motivating and retaining talent at all levels is vital to our continued success. Our employees are a significant asset, and we aim to create an equitable, inclusive and empowering environment in which our employees can grow and advance their careers, with the overall goal of developing, expanding and retaining our workforce to support our current pipeline and future business goals. By focusing on employee retention and engagement, we also improve our ability to support our clinical trials, our pipeline, our platform technologies, business and operations, and also protect the long-term interests of our securityholders. Our success also depends on our ability to attract, engage and retain a diverse group of employees. Our efforts to recruit and retain a diverse and passionate workforce include providing competitive compensation and benefits packages and ensuring we listen to our employees. We value innovation, passion, data-driven decision making, persistence and honesty, and are building a diverse environment where our employees can thrive and be inspired to make exceptional contributions to bring novel and more effective therapies to cancer patients. Our human capital resources objectives include, as applicable, identifying, recruiting, retaining, motivating and integrating our existing and future employees. The principal purposes of our equity incentive plans are to attract, retain and motivate selected employees, consultants and directors through grants of stock-based compensation awards and payments of cash-based performance bonus awards, in order to increase stockholder value and the success of our company by motivating our employees to perform to the best of their abilities and achieve our objectives. We are committed to providing a competitive and comprehensive benefits package to our employees. Our benefits package provides a balance of protection along with the flexibility to meet the individual health and wellness needs of our employees. We plan to continue to refine our efforts related to optimizing our use of human capital as we grow, including improvements in the way we hire, develop, motivate and retain employees. Facilities Our corporate headquarters is located at 830 Winter Street in Waltham, Massachusetts. The facility at 830 Winter Street is 25,472 square feet of laboratory space, with a lease expiration of October 2029. We also lease a facility at 880 Winter Street which is 113,487 square feet of office and laboratory space with a lease termination date of December 2032. We believe that these facilities are adequate to meet our needs for the immediate future, and that, should it be needed, suitable additional space will be available to accommodate any such expansion of our operations. Legal Proceedings We are not currently a party to any material legal proceedings. From time to time, we may become involved in legal proceedings arising in the ordinary course of our business. Regardless of outcome, litigation can have an adverse impact on us due to defense and settlement costs, diversion of management resources, negative publicity, reputational harm and other factors. Available Information Our website address is https://www.tscan.com/ . The information contained on, or that can be accessed through, our website is not incorporated by reference into this Annual Report on Form 10-K or in any other report or document we have filed or may file with the Securities and Exchange Commission, or SEC, and any reference to our website address is intended to be an inactive textual reference only. We will make available on our website, free of charge, our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and any amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act, as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC. The SEC maintains an Internet site, http://www.sec.gov, containing reports, proxy and information statements, and other information regarding issuers that file electronically with the SEC. In addition, we routinely post on the “Investors and Media” page of our website investor and scientific presentations, SEC filings, press releases, public conference calls and webcasts and other statements about our business and results of operations, some of which may contain information that may be deemed material to investors. Accordingly, investors should monitor these portions of our website, in addition to following our press releases, SEC filings, public conference calls and webcasts, as well as our social media channels (our Twitter and LinkedIn). This list of channels may be updated from time to time on our investor relations website and may include other social media channels than the ones described above. The contents of our website or these channels, or any other website that may be accessed from our website or these channels, shall not be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended. 52 Table of Contents A copy of our Corporate Governance Guidelines, and Code of Conduct are posted on our website, https://www.tscan.com and are available in print to any person who requests copies by contacting us by calling (857) 399-9500 or by writing to TScan Therapeutics, Inc., 830 Winter Street, Waltham, Massachusetts 02451, Attention: Zoran Zdraveski.