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Item 1. Business

2026-03-12 compared with 2025-03-28 · 236 added, 151 removed, 669 unchanged (37% of the section changed)

We are an oncology therapeutics company applying advanced technologies to established tumor biology that are intended to efficiently deliver improved cancer treatments.

We are a clinical-stage oncology therapeutics company applying advanced technologies to established tumor biology that are intended to efficiently deliver improved cancer treatments.

We have deep experience in chemistry, formulation, and drug delivery, as well as research, clinical, and commercial pharmaceutical development, resulting in successfully taking product candidates from the clinic to approval, launch, and commercialization.

We recently entered into an intellectual property license agreement (the “WuXi License Agreement”) with WuXi Biologics (Shanghai FX) Co., Ltd.

In December 2024, we entered into an intellectual property license agreement (the “WuXi License Agreement”) with WuXi Biologics (Shanghai FX) Co., Ltd.

(“WuXi Biologics”) for the development and global commercialization of a portfolio of three next generation antibody drug conjugates (“ADCs”) targeting clinically validated, broadly overexpressed tumor antigens in high potential cancer indications with significant unmet need.

These ADCs are constructed utilizing an advanced linker-payload platform called CPT113 that has been shown to provide increased stability in blood circulation and deliver targeted release of a Topoisomerase I (“TOPO1”) inhibitor payload into cancer cells.

These in-licensed assets originated through the collaborative efforts of WuXi Biologics, a leading global contract research, development and manufacturing organization (“CRDMO”), and Hangzhou DAC Biotechnology (“Hangzhou DAC”), a global leader in ADC innovation, where Hangzhou DAC’s CPT113 linker-payload has been conjugated to novel antibodies developed by WuXi Biologics against three tumor targets:

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The antibody targeting SEZ6 is a biparatopic SEZ6 (“biSEZ6”) antibody targeting two different epitopes on SEZ6.

We believe the resulting ADCs will be able to target cancers expressing these respective tumor markers precisely and deliver the potent, cytotoxic TOPO1 inhibitor at the site of cancer.

We believe the resulting ADCs will be able to target cancers expressing these respective tumor markers precisely and deliver the potent, cytotoxic TOP1 inhibitor at the site of cancer.

Each of these ADCs have demonstrated tumor cell binding, tumor cell line cytotoxicity, and in vivo antitumor activity in preclinical models of cancer.

We refer to these in-licensed ADC assets as the "ADC Therapies" herein.

We anticipate submitting three investigational new drug (“IND”) applications with the U.S.

Food and Drug Administration (“FDA”) in the coming 12 to 24 months, starting with HWK-007 for the treatment of solid tumors, including non-small cell lung cancer (“NSCLC”) and ovarian cancer, in the second half of 2025;

HWK-016 for the treatment of cancers of female origin by the end of 2025;

and HWK-206 for the treatment of cancers of neuroendocrine origin in mid-2026.

We submitted investigational new drug (“IND”) applications with the U.S.

Food and Drug Administration (“FDA”) for HWK-007 for the treatment of solid tumors, including non-small cell lung cancer (“NSCLC”) and ovarian cancer, and HWK-016 for the treatment of ovarian and endrometrial cancers, in the fourth quarter of 2025;

and we anticipate submitting an IND for HWK-206 for the treatment of small cell lung cancer ("SCLC") and neuroendocrine tumors (“NETs”) in mid-2026.

The FDA has cleared the IND applications for HWK-007 and HWK-016 and the Phase 1 trials for each asset are now actively recruiting.

We expect data readouts in the first half of 2027 from each trial.

With these three assets, we have the ability to pursue multiple cancer indications with high potential in large addressable patient populations, including and beyond those indications currently expected to be targeted in the upcoming Phase 1 trials.

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We exclusively licensed FYARRO, previously called ABI-009, nab-sirolimus, from Abraxis BioScience, LLC, a wholly owned subsidiary of Celgene Corporation, which is a wholly owned subsidiary of Bristol-Myers Squibb Company (“BMS”) and we refer to the development, production and commercial sale of FYARRO herein as the “FYARRO Business”.

On February 22, 2022, we launched FYARRO in the United States for treatment of advanced malignant PEComa and recognized net product sales of $26.0 million and $24.4 million for the years ended December 31, 2024 and 2023, respectively.

On February 22, 2022, we

launched FYARRO in the United States for treatment of advanced malignant PEComa and recognized net product sales of $7.1 million and $26.0 million for the years ended December 31, 2025 and 2024, respectively.

On December 19, 2024, we entered into a Stock Purchase Agreement (the “Divestiture Agreement”) with KAKEN INVESTMENTS INC., a Delaware corporation (“KAKEN”), KAKEN PHARMACEUTICAL CO., LTD (“Guarantor”), and Aadi Subsidiary, Inc., a Delaware corporation and our former wholly owned subsidiary and the operating company for the FYARRO Business (“Aadi Subsidiary”).

Under the Divestiture Agreement, KAKEN acquired 100% of the outstanding shares of capital stock of Aadi Subsidiary from us at the closing of the transaction for a cash payment of $102.4 million

(following applicable purchase price adjustments under the Divestiture Agreement) (the "FYARRO Divestiture").

Under the Divestiture Agreement, KAKEN acquired 100% of the outstanding shares of capital stock of Aadi Subsidiary from us at the closing of the transaction for a cash payment of $102.4 million (following applicable purchase price adjustments under the Divestiture Agreement) (the "FYARRO Divestiture").

The divestiture transaction closed on March 25, 2025 and, as a result, we no longer operate the FYARRO Business.

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The principal components of our strategy include:

• We leverage “next wave” ADC architecture.

Recently, next wave ADCs have been associated with double-digit improvement in objective response rates (“ORR”) over first generation ADCs against the same target across a variety of solid tumors, including ovarian, breast cancer, and lung cancers.

Next wave ADC architectures are typified by improved linker-antibody stability, optimized pharmacokinetics and improved inhibitor payloads, such as using TOPO1 inhibitor in lieu of monomethyl auristatin E (“MMAE”).

• We leverage an optimized, next-generation ADC architecture.

Recently, next-generation ADCs have been associated with double-digit improvement in objective response rates (“ORR”) over first generation ADCs against the same target across a variety of solid tumors, including ovarian, breast cancer, and lung cancers.

These next-generation ADC architectures are typified by improved linker-antibody stability, optimized pharmacokinetics and improved inhibitor payloads, such as using a TOP1 inhibitor in lieu of monomethyl auristatin E (“MMAE”).

Our ADC Therapies are designed to leverage an optimized, next-generation ADC architecture engineered for selective tumor delivery, modality-leading stability and optimized TOP1 inhibition for maximal tumor killing while minimizing potential toxicity.

• We preferentially pursue clinically validated targets and identify opportunities for differentiation.

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• We innovate antibody design to improve ADC performance .

We strive to develop ADCs that couple next wave ADC architecture with cutting-edge antibody strategies to further improve antibody performance, including, but not limited to, high affinity, biparatopic, Fc modifications that increase ADC potency or safety.

We strive to develop ADCs that couple next-generation ADC architecture with cutting-edge antibody strategies to further improve antibody performance, including, but not limited to, high affinity, biparatopic, Fc modifications that increase ADC potency or safety.

• We focus our development strategies to demonstrate differentiation of our assets compared to first generation ADCs to maximize our asset’s competitive profile.

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We plan to utilize an outsourced model for research, development and manufacturing operations.

Initially, we intend to continue to benefit from the continuity of partnership with WuXi Biologics and Hangzhou DAC for near-term IND-enabling studies and ADC manufacturing.

Initially, we intend to continue to benefit from the continuity of partnership with WuXi Biologics and Hangzhou DAC for ADC manufacturing.

We will expand our CRDMO network as appropriate as our portfolio advances further in clinical trials.

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The three tumor targets we selected – PTK7, MUC16 and SEZ6 – are each validated by a first-generation ADC that demonstrated promising efficacy in key indications, but were discontinued, largely due to safety and limited therapeutic index.

Importantly, we prioritized the ability to be in the clinic quickly, and we expect to file INDs in the next 12 to 24 months, starting with our PTK7-directed asset in the second half of 2025, followed closely by the MUC16-directed asset by the end of 2025, and the SEZ6-directed asset in mid-2026.

• HWK-007 presents a differentiated opportunity to be among the first next wave ADCs in clinical development for high PTK7 expressing cancers, including NSCLC, ovarian cancer, and several other major indications.

• HWK-016 is potentially the first ADC that targets membrane-bound portion of MUC16, a glycoprotein often overexpressed in cancers of female origin, such as ovarian cancer, endometrial cancer, cervical cancer, or breast cancer.

Importantly, we prioritized the ability to be in the clinic quickly, filing INDs for HWK-007, our PTK7-directed asset, and HWK-016, our MUC16-directed asset, in the fourth quarter of 2025 and we anticipate filing an IND for HWK-206, our SEZ6-directed asset, in mid-2026.

The FDA has cleared the IND applications for HWK-007 and HWK-016 and the Phase 1 trials for each asset are now actively recruiting.

We expect data readouts in the first half of 2027 from each trial.

• HWK-007 presents a differentiated opportunity as one of the first next-generation ADCs in clinical development for high PTK7 expressing cancers, including NSCLC, ovarian cancer, and several other major indications.

• HWK-016 is potentially the first ADC that targets membrane-bound portion of MUC16, a glycoprotein "super expressed" in gynecological cancers, including ovarian cancer, endometrial cancer and cervical cancer.

• HWK-206 is designed to bind to two epitopes on SEZ6, which is often overexpressed in cancers of neuroendocrine origin.

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We believe that improving ADC architecture can increase treatment efficacy in solid tumors.

Each of the ADC Therapies utilizes the advanced CPT113 linker-payload technology from Hangzhou DAC, which consists of a highly stable yet cleavable linker that delivers a TOPO1 inhibitor payload, and high affinity antibodies designed using the industry-leading antibody capability of Wuxi Biologics.

Each of the ADC Therapies utilizes the advanced CPT113 linker-payload technology from Hangzhou DAC, which consists of a highly stable yet cleavable linker that delivers a TOP1 inhibitor payload, and high affinity antibodies designed using the industry-leading antibody capability of Wuxi Biologics.

The portfolio leverages an advanced ADC platform technology and are engineered for minimal off-target toxicity, greater stability and higher therapeutic index.

We believe these assets can potentially overcome the limitations that hindered the first generation ADC therapies against these targets to deliver improved results for patients.

We believe these assets can potentially overcome the limitations that hindered the first generation ADC therapies, and show superior performance to other next generation ADCs in development, to deliver improved results for patients.

Under the WuXi License Agreement, we have worldwide development and commercialization rights to all of our product candidates.

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This targeted approach can limit off-target toxicities of chemotherapy and/or allow for greatly improved potency against cancer.

With these improvements in cancer outcomes, the ADC market with an estimated $11 billion in sales at the end of 2023 is expected to grow to over $50 billion by 2030.

With these improvements in cancer outcomes, the ADC market with an estimated nearly $11 billion in sales at the end of 2024 is expected to grow to over $23 billion by 2030, with some estimates as high as $50 billion.

As of the end of 2025, 15 ADCs have been approved by the FDA (mostly first generation;

two have been withdrawn) against multiple cancers, including blood, breast, and lung cancers.

two have been withdrawn) against multiple cancers, including blood, breast, gynecological and lung cancers.

Despite the benefit seen with first generation ADCs, there continues to be significant need for improved ADCs with safer payloads, improved stability and optimized pharmacokinetics.

For example, first generation ADCs often use tubulin inhibitor-based payloads, such as MMAE-based payloads, that have been associated with a class effect of dose-limiting toxicities, like peripheral neuropathy, ocular toxicities and neutropenia.

Next wave ADCs

Recent advances in ADCs have included replacing the tubulin inhibitor-based payloads with Topoisomerase I (“TOPO1”) inhibitor payloads to reduce toxicity, improving linker stability to reduce circulating free payload, and increasing and optimizing the drug-to-antibody ratio (“DAR”) to improve pharmacokinetics and antitumor activity.

In a number of ADC programs, next generation ADCs were shown to have improved ORR by 20-40% over their first-generation precursors.

For example, the ORR for ABBV-011, a calicheamicin-based ADC with a DAR of 2 and a non-cleavable linker, in small cell lung cancer (“SCLC”) was 19%, while the ORR for ABBV-706, a next wave ADC with a TOPO1 inhibitor payload and a DAR of 6, was 61%, representing a 42% higher response rate compared to ABBV-011.

Next-generation ADCs

Recent advances in ADCs have included replacing the tubulin inhibitor-based payloads with Topoisomerase I (“TOP1”) inhibitor payloads to reduce toxicity, improving linker stability to reduce circulating free payload, and increasing and

optimizing the drug-to-antibody ratio (“DAR”) to improve pharmacokinetics and antitumor activity.

In a number of ADC programs, next generation ADCs were shown to have improved ORR by approximately 15-45% over their first-generation precursors.

For example, the ORR for ABBV-011, a calicheamicin-based ADC with a DAR of 2 and a non-cleavable linker, in small cell lung cancer (“SCLC”) was 19%, while the ORR for ABBV-706, a next-generation ADC with a TOP1 inhibitor payload and a DAR of 6, was 56%, representing a 37% higher response rate compared to ABBV-011.

1 Overall response rate in indicated Phase I patients;

exception, Elahere phase III data in ovarian cancer

FRa, Folate receptor alpha;

DM4, Ravtansine (tubulin inhibitor);

TOPO1, Topoisomerase I inhibitor;

MMAE, Monomethyl Auristatin E (tubulin inhibitor) OvCa, Ovarian Cancer;

TNBC, Triple negative breast cancer;

SCLC, Small cell lung cancer;

NSCLC, non-small cell lung cancer;

HER2+ BC, Human Epidermal Growth Factor Receptor 2 positive breast cancer.

Published data;

Whitehawk analysis.

Regarding a target in our portfolio, PTK7, the graphs below demonstrate the placement of phase 1 cofetuzumab pelidotin (“Cofe-P”) data – an established PTK7 benchmark – in the context of currently approved or late-stage ADC benchmarks for efficacy in ovarian and lung cancers.

Our product candidate, HWK-007, is a PTK7 switch to an advanced platform, and therefore extrapolating from the prior examples above, we believe there could be meaningful efficacy gains in objective response rate over Cofe-P.

Elahere and Rina-S.

Trodelvy and Datroway.

Maitland et al.

Clin Cancer Research, 2021:

Elahere USPI and Lee, E.K.

Annals of Oncology, Volume 35, S550;

Paz-Ares L, Goto Y, Lim WDT, et al.

Journal of Clinical Oncology.

2024;42(24):2860-2872.;

Myung-Ju Ahn et al.

JCO 43, 260-272(2025).

DOI:10.1200/JCO-24-01544.

ORR, objective response rate;

Cofe-P, Cofetuzumab pelidotin.

Our Approach:

CPT113-based ADC platform

Each of the ADC Therapies utilizes Hangzhou DAC’s CPT113 platform, which consists of a highly stable yet cleavable linker with proprietary carbon-bridge technology that delivers a TOPO1 inhibitor payload.

We believe that the CPT113 platform’s linker stability and payload has the potential to be highly competitive among the next generation ADC platforms.

Hangzhou DAC selectively designed and synthesized an advanced linker and payload design that supports stability, limits free payload release and improves the pharmacokinetic characteristics for the associated ADCs.

Separately from the ADC Therapies we are licensing, Hangzhou DAC has two internally developed programs utilizing the same platform, DXC006 and DXC1002, that are currently in dose-escalating Phase 1 clinical trials in China.

A critical feature of the CPT113 platform is its stability.

First generation ADCs were challenged by high free payload release in circulation.

Many approved and marketed ADCs have 1 to 20 percent free payload released into the circulation, which limits their therapeutic windows because the high amounts of free payload can generate off-target side effects.

Next generation ADC platforms in development generally seek to lower the amounts of free payload released into circulation.

Based on reported pharmacokinetic results across different ADC programs, as shown in the figure below, the CPT113 platform is likely on par with or better than these latest platforms, demonstrating its highly competitive stability.

Separately from the ADC Therapies we are licensing, Hangzhou DAC has two internally developed programs utilizing the same platform and directed to different targets, DXC006 and DXC1002, that are currently in dose-escalating Phase 1 clinical trials in China.

Based on highest species reported in publications on file;

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Calculated based on molar concentration of free payload and ADC in representative pharmacokinetic studies.

The payload component of CPT113 is a proprietary TOPO1 inhibitor based on a modified form of exatecan.

Exatecan is a semisynthetic, water-soluble derivative of camptothecin, a naturally occurring plant alkaloid that is known for its TOPO1 inhibition and antitumor activity.

TOPO1 are necessary for normal and tumor cell growth, as they are involved in DNA supercoiling and repackaging of DNA during cell division.

Inhibition of TOPO1 prevents DNA from rejoining, thereby causing DNA breaks and leading to cell death.

The payload component of CPT113 is a proprietary TOP1 inhibitor based on a modified form of exatecan.

Exatecan is a semisynthetic, water-soluble derivative of camptothecin, a naturally occurring plant alkaloid that is known for its TOP1 inhibition and antitumor activity.

TOP1 are necessary for normal and tumor cell growth, as they are involved in DNA supercoiling and repackaging of DNA during cell division.

Inhibition of TOP1 prevents DNA from rejoining, thereby causing DNA breaks and leading to cell death.

Although exatecan has shown some antitumor activity, it has been associated with acute toxicity when delivered freely in the circulation, however, has been found to be highly effective as an ADC payload due to its ability to improve the overall efficacy and toxicity of the ADC.

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Trastuzumab deruxtecan (“T-DXd”), an ADC consisting of a humanized mAb trastuzumab (Herceptin) covalently linked to DXd, is approved for treatment of breast cancer, gastric cancer and gastroesophageal adenocarcinoma and sold by Daiichi Sankyo.

Our payload has similar structure, cytotoxicity and preclinical safety profile to DXd.

Based on preclinical models of exatecan, our modified version retains potency and with our proprietary bioconjugation has minimal toxicity in regards to impact on the bone marrow.

This heme-sparing profile helps address challenges like severe neutropenia that has emerged with exatecan-based and other TOP1 ADCs.

One advantage of the CPT113 platform is its relatively high stability.

Many first generation ADCs were challenged by high free payload release in circulation.

Next generation ADC platforms in development generally seek to lower the amounts of free payload released into circulation.

An important component to this stability is bioconjugation, or how the linker-payload is attached to the antibody.

We estimate that more than 95% of new TOP1 ADCs in clinical development today still use an older bioconjugation process defined by single-chain, partial site-specific bioconjugation.

The single chain bioconjugation process breaks the disulfide bonds that normally hold antibody heavy and light chains together – there are four paired bonds of eight cysteines that are broken.

Many ADC developers add their single chain linker payloads onto those cysteines to form a typical DAR8 TOP1 ADC.

chain bioconjugation is relatively simple, but inherently unstable.

First, the removal of the normal disulfide bridges between antibody chains can make the whole antibody component of the ADC less stable.

Second, once the ADC is exposed to conditions in the circulation, each single chain linker-payload conjugation may besubject to attack and cleavage due to conditions in the blood releasing free payload into circulation – payload that is no longer targeted to the tumor and can circulate to damage normal tissue.

In essence, standard single chain conjugation is relatively fragile and may be prone to free payload release that could lead to high rates of class payload toxicities.

Conversely, CPT113 adds linker-payloads on to the mAb as carbon-bonded pairs – that is two linker-payloads that are covalently bound together are added to the exact location where the disulfides on monoclonals have previously been broken.

This strategy effectively re-bridges the native paired cysteines, replacing the disulfide bond with a new carbon bond in the linker.

This “carbon bridge cysteine re-pairing” method restores the antibody’s more natural state, which we have demonstrated preclinically to enhance overall ADC stability beyond what is traditionally achieved by single chain bioconjugation.

We also employ an additional bioconjugation step - linker hydrolysis - to lock the carbon bridge structure of the ADC, further improving stability, reducing free payload release and limiting potential payload toxicity.

In addition to the exatecan-based TOP1 design, we have further optimized our linker-payload.

We utilize PEG-based masking to optimize hydrophobicity of our linker, supporting longer ADC half-life in circulation and optimal ADC dosing.

We layer on to that a novel, triple-peptide, intracellular cleavage site that ensures a controlled release profile of cytotoxic payload only once the ADC is inside the tumor cell.

Taken together, we believe these elements represent an elegant and cohesive engineering solution designed to deliver best-in-class stability, safety and tumor potency.

We believe that TOP1-based platforms are not all created equal.

Based on key preclinical measures of tumor potency, stability and safety, the ADC Therapies demonstrated quantifiable advantages compared with the average TOP1-based ADCs.

Regarding tumor potency, across xenograft models our ADC Therapies achieve tumor reduction at doses roughly 3 to 10 times lower than conventional TOP1-based ADCs.

This increased potency can translate lower minimally effective dose needed to achieve tumor regression in humans.

In addition, we consistently see 5 to 25 times lower levels of free payload in plasma in our ADC Therapies in nonclinical models compared to other TOP1-based ADCs.

This advantage in stability is a function of our “carbon bridge cysteine re-pairing” and other aspects of our novel chemistry which sequesters the payload in place until it reaches the tumor cell.

Finally, due to improved targeting, stability and novel payload, we observe a 2 to 3 times higher safety margin in nonclinical models of our ADC Therapies than the typical TOP1-based ADCs.

Taken together, we believe we have a differentiated next-generation platform with the potential for powerful tumor killing and lower side effects.

Our Product Candidates

Our lead product candidate HWK-007 is a next wave ADC with a DAR of 6 targeting PTK7 that we plan to develop for the treatment of non-small cell lung cancer (“NSCLC”) and platinum resistant ovarian cancer (“PROC”), with potential to expand into other indications.

We believe HWK-007 has the potential to be among the first in next wave ADCs with a TOPO1 inhibitor payload to enter the clinic.

With its optimized linker and TOPO1 inhibitor payload, we hope to improve upon the initial ORRs seen with cofetuzumab pelidotin (“Cofe-P”), a first generation MMAE-based ADC with a DAR 4 targeting PTK7.

HWK-007 is a differentiated next-generation ADC with a DAR of 6 targeting Protein Tyrosine Kinase 7 (PTK7).

There are no approved PTK7-directed ADCs.

Following the submission of an IND in the fourth quarter of 2025 and the FDA's subsequent clearance of the IND, HWK-007 is now being explored in a Phase 1 trial that will initially evaluate activity in lung and ovarian cancers, two

PTK7-expressing tumor types with established precedent data, as well as endometrial cancer, one of the highest PTK7-expressing tumor types.

We expect data readout in the first half of 2027 from the Phase 1 trial.

HWK-007 has shown superior cytotoxic activity compared to a first generation MMAE-based PTK7 ADC in both in vitro and in vivo preclinical models.

We are currently completing IND-enabling studies and expect to submit an IND for the use of HWK-007 in treating solid tumors, including NSCLC and PROC, in the second half of 2025.

With its optimized linker and TOP1 inhibitor payload, we hope to improve upon the initial ORRs seen with Cofe-P, a first-generation MMAE-based ADC with a DAR 4 targeting PTK7.

Target Overview:

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PTK7 is subsequently down-regulated in adult tissues and is known as a catalytically inactive receptor tyrosine kinase (RTK).

PTK7 is commonly upregulated across a broad spectrum of cancers, being found in tumors associated with endometrial, prostate, cervical, head and neck, breast, colorectal, esophageal, lung, ovarian and gastric intestinal cancers, as shown in the figure below.

In fact, PTK7 is almost exclusively re-expressed in primary and metastatic tumor cells and cancer associated fibroblasts (“CAFs”) in the tumor microenvironment.

A large-scale RNA analysis of >157,000 tumor samples, nearly half from metastatic lesions, found PTK7 to be the third most highly expressed tumor marker among clinically validated and emerging ADC targets, present in approximately 70% of tumors.

Highest median PTK7 mRNA expression was observed in endometrial (7.4), ovarian (7.2), head and neck (7.1), non-small cell lung cancer (NSCLC) (6.9) and breast (6.7) tumors.

The analysis found stable expression across disease stages and metastatic status, underscoring relevance in both early- and late-stage disease.

It also found expression levels comparable to or exceeding clinically validated and emerging ADC targets:

• Lung cancer:

Comparable to HER2, HER3, Trop-2 and cMET.

• Ovarian cancer:

Comparable to HER2 and FRα;

markedly higher than CDH6, B7-H4 and CLDN6.

• Endometrial cancer:

Comparable to Trop-2;

markedly higher than FRα, B7-H4 and HER2.

We estimate that nearly 750,000 patients have PTK7-positive cancers in the United States alone, underscoring its potential as a tumor marker.

PTK7 is almost exclusively re-expressed in primary and metastatic tumor cells and cancer associated fibroblasts (“CAFs”) in the tumor microenvironment.

PTK7 is known to promote cancer growth and invasion.

Overexpression of PTK7 is associated with poor prognosis, tumor metastasis, and reduced overall survival.

Whitehawk analysis based on Human Protein Atlas, Gepia, and literature review.

Matulonis, et al., Real-World Characterization of PTK7, an Oncofetal Pseudokinase Expressed in Multiple Solid Tumors [Poster], presented at ENA 2025.

Gene expression data were derived from a whole-transcriptome RNA-sequencing panel (Tempus’ xR) capturing 20,000 genes.

Among clinically validated and emerging ADC targets.

Across 17 indications (pan-cancer, N=122,228), weighted by SEER incidence.

TPM, transcripts per million

PTK7 is a clinically validated tumor target.

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Although there are currently no approved ADCs targeting PTK7, there are multiple PTK7 programs currently in, or about to begin, clinical development, some of which are described here:

• PRO1107, being developed by Genmab following its acquisition of ProfoundBio, is currently in Phase 1/2 with the first patient dosed in February 2024.

PRO1107 uses an MMAE payload, which is a tubulin inhibitor similar to the payload in Cofe-P, connected through a protease-cleavable hydrophilic linker system called LD343, and has a DAR of 8.

• DAY301 (MTX-13), being developed by Day One Biopharmaceuticals after acquiring development and commercialization rights outside of the Greater China area from MabCare Therapeutics, recently initiated a Phase 1 trial.

Unlike Cofe-P and PRO1107, DAY301 has a pure exatecan payload which may be associated with myelosuppression.

LY4175408, being developed by Eli Lilly, also has a pure exatecan payload.

We expect Eli Lilly will submit its IND in 2025.

• LY4175408, being developed by Eli Lilly, also has a pure exatecan payload and is being explored in a Phase 1 trial.

• SKB518, being developed by Kelun Biotech, is currently in Phase 1 in China.

We expect multiple external PTK7 ADC programs are projected to present clinical data in 2025 to 2027, which will further validate our target and TOPO1 inhibitor payload approach.

Additionally, there are multiple preclinical PTK7 bispecific ADCs in development, including the PTK7 x B7-H3 ADC recently acquired by IDEAYA Biosciences.

• KIVU-107, being developed by Kivu Bioscience, uses a pure exatecan payload and is being explored in a Phase 1 trial.

• IDE034, being developed by Ideaya Biosciences, an investigational PTK7/B7H3 bispecific TOP1 ADC being explored in a Phase 1 trial.

We expect multiple external PTK7 ADC programs are projected to present clinical data in 2026 to 2027, which will further validate our target and TOP1 inhibitor payload approach.

Additionally, there are multiple preclinical PTK7 bispecific ADCs in development.

There are a number of other ADC programs in development for NSCLC targeting other tumor-associated antigens.

Our Product Candidate:

HWK-007, as a differentiated next wave PTK7-directed ADC, is poised to be among the first in next wave ADCs with an alternate TOPO1 inhibitor payload to enter the clinic.

With its optimized linker and TOPO1 inhibitor payload switch, we are targeting to build on the initial ORRs seen with Cofe-P and potentially deliver superior outcomes for patients.

HWK-007, as a differentiated next-generation PTK7-directed ADC, is poised among the first in next-generation ADCs with an alternate TOP1 inhibitor payload to enter the clinic.

With its optimized linker and TOP1 inhibitor payload switch, we are targeting to build on the initial ORRs seen with Cofe-P and potentially deliver superior outcomes for patients.

HWK-007 has already demonstrated superior tumor reduction compared to Cofe-P in both in vitro and in vivo preclinical models.

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Clinical Development Plan

We plan to complete IND-enabling studies, linker-payload process development, and CMC and submit an IND for the treatment of solid tumors, including NSCLC and PROC, in the second half of 2025.

Subject to FDA acceptance, we plan to initiate a Phase 1 trial by the end of 2025.

Our product candidate HWK-016 is a next wave ADC targeting the membrane-bound portion of MUC16, a glycoprotein often overexpressed in cancers of female origin, such as ovarian cancer, endometrial cancer, cervical cancer, or breast cancer.

MUC16 has been previously a challenging target because a large part of its extracellular portion is often cleaved and released or “shed” into the bloodstream, often called cancer antigen 125 (“CA125”).

In the fourth quarter of 2025, we completed IND-enabling studies and linker-payload process development, submitted an IND for the treatment of solid tumors, including NSCLC, PROC and endometrial, and initiated a Phase 1 trial for HWK-007.

The Phase 1 clinical trial, HWK-007-101, is a Phase 1, multicenter, open-label study in adult participants that will employ a sequential dose-escalation and expansion design to evaluate the safety, pharmacokinetics and preliminary antitumor activity of HWK-007 in participants with advanced or metastatic solid tumors that are refractory to standard therapies.

We expect data readout in the first half of 2027 from HWK-007-101.

Our product candidate HWK-016 is a next-generation ADC targeting the membrane-bound portion of MUC16, a glycoprotein "super expressed" in gynecological cancers, such as ovarian, endometrial and cervical cancers.

been previously a challenging target because a large part of its extracellular portion is often cleaved and released or “shed” into the bloodstream, often called cancer antigen 125 (“CA125”).

HWK-016 is specifically designed to bind to the membrane-bound portion, which we believe can enable greater therapeutic effect at lower doses.

We plan to develop HWK-016 initially for the treatment of PROC, with potential expansion to other ovarian cancers, endometrial cancer, and/or cervical cancer, aiming to deliver a potential best-in-class treatment for these large patient populations.

We plan to develop HWK-016 initially for the treatment of ovarian and endometrial cancers, aiming to deliver a potential best-in-class treatment for these large patient populations.

Our in vitro and in vivo studies show consistent cytotoxic activity by HWK-016, including in the presence of CA125, suggesting that our product candidate does bind to the right epitope.

Our product candidate also has an optimized linker and improved TOPO1 inhibitor payload, which we expect can improve response rate and reduce toxicity.

We plan to complete IND-enabling studies and submit an IND for the treatment of ovarian cancer by the end of 2025.

Our product candidate also has an optimized linker and improved TOP1 inhibitor payload, which we expect can improve response rate and reduce toxicity.

We submitted an IND for the treatment of ovarian cancer in the fourth quarter of 2025, which was subsequently cleared by the FDA, and initiated a Phase 1 clinical trial of HWK-016 in participants with advanced or metastatic solid tumors that are refractory to standard therapies in the first quarter of 2026 .

We expect data readout in the first half of 2027 from the Phase 1 trial.

Target Overview:

Mucin 16 (MUC16)

Mucin 16 (MUC16) is a heavily glycosylated type 1 transmembrane protein with a low level of expression in normal bronchial, endometrial, ovarian and corneal epithelial cells.

MUC16 is upregulated in a number of cancers, including ovarian cancer, endometrial cancer, cervical cancer, or breast cancer, as well as NSCLC, pancreatic and gastric cancers.

MUC16 is upregulated in a number of cancers, with broad overexpression - or "super expression" - in gynecological tumors including ovarian, cervical and endometrial.

In ovarian cancer, for example, MUC16 is present at rates up to 3-10 times higher than clinically validated and emerging ADC targets.

Overexpression of MUC16 promotes cancer cell proliferation and chemoresistance, while also inhibiting anti-cancer immune responses.

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MUC16 interacts with various signaling pathways and proteins, such as the JAK2/STAT3/GR axis, PI3k, EGFR and Src family kinases.

Whitehawk analysis based on Human Protein Atlas, Gepia, and literature review.

Pan-cancer, N=4030.

TPM, transcripts per million.

Data on file.

RNA sequencing data (Tempus AI, Inc.) were used to examine MUC16 expression across ovarian cancer histologic subtypes.

Median mRNA expression was quantified as log2(transcripts per million [TPM]+1 and differences were evaluated using the Kruskal-Wallis test.

MUC16 consists of an O-glycosylated N-terminal domain, a tandem repeat domain, approximately 56 SEA (sperm protein, enterokinase and agrin) domains, a transmembrane domain and a cytoplasmic tail.

MUC16 is unique in its large number of SEA domains, as other mucins such as MUC1, MUC12, MUC13, and MUC17 only possess a single SEA module.

SEA domains and their functions are not fully understood but MUC16 is speculated to have two proteolytic sites in the SEA domains, at the 55 th and 56 th SEA domains.

domains and their functions are not fully understood but MUC16 is speculated to have two proteolytic sites in the SEA domains, at the 55 th and 56 th SEA domains.

It is believed that MUC16 cleavage occurs at these sites, whereby CA125 is released or “shed” into the bloodstream.

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Common adverse events included fatigue, nausea, abdominal pain, constipation, blurred vision, diarrhea, anemia and peripheral neuropathy.

Additionally, lower doses did not produce

objective responses, likely due to a portion of the ADC binding to circulating CA125.

Additionally, lower doses did not produce objective responses, likely due to a portion of the ADC binding to circulating CA125.

Consequently, higher doses were necessary to first saturate most of the circulating CA125 before achieving therapeutic efficacy and tumor cell killing.

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Emerging Therapies and their Limitations

Currently, there are no approved or actively developing ADCs targeting MUC16.

Currently, there are no approved ADCs targeting MUC16.

Regeneron is developing two MUC16 bispecific T cell-engaging antibodies;

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Our product candidate is designed to bind to a different region than the targets of prior MUC16 therapies in development.

HWK-016 targets membrane-bound MUC16 (mMUC16) below the site of cleavage, so that even if MUC16 is cleaved and release of CA125 occurs, the ADC can stay bound to the cell surface permitting internalization of the TOPO1 inhibitor payload.

This allows HWK-016 to bypass the antigen sink of circulating CA125, and directly target the tumor surface.

Preclinical data shows that HWK-016 demonstrates superior tumor growth inhibition in vivo compared to DMUC4064A in a high CA125-shedding model of ovarian cancer.

In vitro and in vivo data suggest that this next wave approach has the potential for improved response rates in ovarian cancer and other gynecological cancers.

For example, our product candidate HWK-016, along with DMUC and mMUC16 antibodies conjugated to DXd and MMAE payloads, were tested in an in vivo OVCAR-3 CDX model.

In vitro and in vivo data suggest that this next-generation approach has the potential for improved response rates in ovarian cancer and other gynecological cancers.

For example, our product candidate

HWK-016, along with DMUC and mMUC16 antibodies conjugated to DXd and MMAE payloads, were tested in an in vivo OVCAR-3 CDX model.

Nude mice bearing the OVCAR-3 tumor xenograft were treated with a single dose of ADC at 1 mg/kg.

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Clinical Development Plan

We plan to complete IND-enabling studies and linker-payload process development in 2025 with IND submission by the end of 2025.

Subject to FDA acceptance, we plan to initiate Phase 1 trial in ovarian cancer in 2026, with the potential to expand into other cancers affecting women, such as endometrial and cervical cancer, where we believe HWK-016 can make a meaningful impact.

We completed IND-enabling studies and linker-payload process development in 2025 and submitted an IND in the fourth quarter of 2025.

In the first quarter of 2026, we initiated HWK-016-101, a Phase 1, multicenter, open-label study in adult participants that will employ a sequential dose-escalation and expansion design to evaluate the safety, tolerability, pharmacokinetics and preliminary antitumor activity of HWK-016 in participants with advanced or metastatic solid tumors that are refractory to standard therapies.

We expect data readout in the first half of 2027 from HWK-016-101 .

Our product candidate HWK-206 is a biparatopic ADC targeting to two epitopes on the SEZ6 protein.

There is limited class competition as ABBV-706 is the only clinical-stage SEZ6 ADC currently in development.

Our product candidate is the only biparatopic ADC in development for SCLC and high-grade neuroendocrine tumors (“NET”) patients, and we believe this approach of binding to two independent sites on the target antigen protein will achieve superior outcomes compared to other SCLC ADCs.

There is limited class competition as we believe ABBV-706 is the only clinical-stage SEZ6 ADC currently in development.

We believe our product candidate is the only biparatopic ADC in development for SCLC and NETs patients and that this approach of binding to two independent sites on the target antigen protein will achieve superior outcomes compared to other SCLC ADCs.

In vitro and in vivo assays demonstrate increased binding and internalization compared to the monotopic ABBV-706.

We plan to complete IND-enabling studies and linker-payload process development in 2025 and first half of 2026, with an IND submission planned in mid-2026.

We plan to complete IND-enabling studies and linker-payload process development in the first half of 2026, with an IND submission planned in mid-2026.

Target Overview:

Seizure-related homolog protein 6 (SEZ6)

Seizure-related homolog protein 6 (SEZ6) is a transmembrane protein commonly expressed on neurons, particularly neuronal dendrites, but minimally expressed in normal tissues outside the central nervous system (“CNS”).

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Emerging Therapies and their Limitations

Currently, ABBV-706 (developed by AbbVie) is the only clinical stage SEZ6 ADC in development.

ABBV-706 is a TOPO1 inhibitor-based ADC (DAR 6) with a cleavable linker.

In a Phase 1 trial in patients with SCLC and neuroendocrine neoplasms (“NEN”), ABBV-706 demonstrated an overall ORR of 44% (21/48, excludes n=5 with glioblastoma multiforme (“GBM”)), with 60.9% ORR in SCLC and 28% ORR in NENs.

Currently, we believe ABBV-706 (developed by AbbVie) is the only clinical stage SEZ6 ADC in development.

ABBV-706 is a TOP1 inhibitor-based ADC (DAR 6) with a cleavable linker.

In a Phase 1 trial in patients with SCLC and neuroendocrine neoplasms (“NEN”), ABBV-706 demonstrated 56% ORR in SCLC at the RP2D of 1.8mg/kg and 37% ORR in NENs.

ABBV-706 demonstrated a manageable safety profile with no on-target neurotoxicity.

The promising results with ABBV-706 validated SEZ6 as a target and demonstrated clinical improvement by switching to a cleavable TOPO1 inhibitor linker-payload.

Of note, 77% (41/53) of patients experienced Grade 3 or higher treatment-emergent adverse events (“TEAEs”) with cytopenias being the most frequent.

32% of patients experienced severe adverse events (“SAEs”), with pneumonia being the most common.

Anemia (60%) and fatigue (66%) were the most common any-grade hematologic and non-hematologic TEAEs, respectively.

The maximum tolerable dose (“MTD”) was 3.0 mg/kg, with hematological dose limiting toxicities (“DLTs”) occurring in 2 patients:

one Grade 4 leukopenia and neutropenia lasting >7 days and one Grade 4 thrombocytopenia.

All gastrointestinal toxicities were Grade 1 or 2 and no neurotoxicity or GBM was observed suggesting that there is no intracranial penetration.

While ABBV-706 represents important progress for SCLC, we believe there are opportunities to apply novel ADC engineering to provide a path to even greater gains.

The promising results with ABBV-706 validated SEZ6 as a target and demonstrated clinical improvement by switching to a cleavable TOP1 inhibitor linker-payload.

Of note, the most common grade ≥3 treatment-emergent adverse events (“TEAEs”) in the 1.8 mg/kg and 2.5 mg/kg cohorts were hematological and dose-dependent.

Adjudicated interstitial lung disease (ILD) of any grade was observed in 7 patients (9%) overall (1.8 mg/kg, n=4;

2.5 mg/kg, n=3), with Grade ≥3 ILD events reported in 4 patients (1.8 mg/kg, n=2;

2.5 mg/kg, =2).

While ABBV‑706 may represent an important advance in the treatment of small cell lung cancer, these findings highlight opportunities for continued innovation in antibody–drug conjugate engineering to further improve safety and tolerability.

Our Product Candidate:

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Zanidatamab demonstrated approximately 20% increase in ORR compared to monoparatopic trastuzumab while maintaining a tolerable safety profile.

Our biparatopic SEZ6 ADC, HWK-206, is the only biparatopic ADC in development for small cell lung cancer, and shows potential to outperform the available treatment approaches and the single epitope-binding ADCs in development.

We believe our biparatopic SEZ6 ADC, HWK-206, is the only biparatopic ADC in development for SCLC and NETs, and shows potential to outperform the available treatment approaches and the single epitope-binding ADCs in development.

Preclinical models suggest the biSEZ6 antibody shows superior binding and internalization compared to single epitope SEZ6 antibody counterparts, including the antibody used in ABBV-706, with increased mean fluorescence intensity (MFI).

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As a result, we cannot guarantee that the ADC Therapies will be protected or remain protectable by enforceable patents.

Moreover, any patents that we hold may be challenged, circumvented, or invalidated by third parties.

Moreover, any patents that

we hold may be challenged, circumvented, or invalidated by third parties.

For more information regarding the risks related to our intellectual property please see “Risk Factors—Risks Related to Our Intellectual Property”.

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Only one patent among those eligible for an extension and only those claims covering the approved drug, a method for using it, or a method for manufacturing it may be extended.

Similar provisions are available in Europe and in certain other jurisdictions to extend the term of a patent that covers an approved dr ug.

We also intend t o seek patent term extensions in any jurisdictions where they are available, however, there is no guarantee that the applicable authorities, including the FDA, will agree with our assessment of whether such extensions should be granted, and even if granted, the length of such extensions.

In addition to patent protection, we also rely on trade secret protection for our proprietary information that is not amenable to, or that we do not consider appropriate for, patent protection, including, for example, certain aspects of our manufacturing processes for the nanoparticle compositions.

Similar provisions are available in Europe and in certain other jurisdictions to extend the term of a patent that covers an approved drug.

We also intend to seek patent term extensions in any jurisdictions where they are available, however, there is no guarantee that the applicable authorities, including the FDA, will agree with our assessment of whether such extensions should be granted, and even if granted, the length of such extensions.

In addition to patent protection, we also rely on trade secret protection for our proprietary information that is not amenable to, or that we do not consider appropriate for, patent protection.

However, trade secrets can be difficult to protect.

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As of March 9, 2026, patent rights held by us relating to our ADC drug candidates include the following:

• With respect to the PTK7 targeting drug candidate, our material patents consist of one People’s Republic of China (PRC) patent application exclusively licensed from WuXi Biologics and directed to the PTK7 ADC drug candidate, which we intend to pursue patent protection for in key jurisdictions.

This application, if issued, is expected to expire in at least 2046, without taking into account any possible patent term adjustments or extensions and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees.

• With respect to the SEZ6 targeting drug candidate, our material patents consist of one PRC patent application exclusively licensed from WuXi Biologics and directed to the SEZ6 ADC drug candidate, which we intend to pursue patent protection for in key jurisdictions.

• With respect to the MUC16 targeting drug candidate, our material patents consist of one PRC patent application exclusively licensed from WuXi Biologics and directed to the MUC16 ADC drug candidate, which we intend to pursue patent protection for in key jurisdictions.

• With respect to the PTK7 targeting drug candidate, our material patents consist of one U.S patent application and related patent applications in Asia and South America exclusively licensed from WuXi Biologics and directed to the PTK7 ADC drug candidate, and two provisional applications which we intend to pursue patent protection for in key jurisdictions.

These applications, if issued, are expected to expire in at least 2046, without taking into account any possible patent term adjustments or extensions and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees.

• With respect to the SEZ6 targeting drug candidate, our material patents consist of patent applications in Asia and South America exclusively licensed from WuXi Biologics and directed to the SEZ6 ADC drug candidate, which we intend to pursue patent protection for in key jurisdictions.

These applications, if issued, is expected to expire in at least 2046, without taking into account any possible patent term adjustments or extensions and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees.

• With respect to the MUC16 targeting drug candidate, our material patents consist of one U.S patent application and related patent applications in Asia and South America exclusively licensed from WuXi Biologics and directed to the MUC16 ADC drug candidate and one U.S.

provisional application, which we intend to pursue patent protection for in key jurisdictions.

Many companies are active in the oncology market and are developing or marketing products for the specific therapeutic markets that we target, including both antibody- and non-antibody-based therapies.

Similarly, we also face competition from other companies and institutions that continue to invest in innovation in the ADC field, including new payload classes, new conjugation approaches and new targeting moieties.

Specifically, we are aware of multiple companies with ADC technologies that may be competitive with our products and product candidates, including, but not limited to, AbbVie, Daiichi Sankyo, Day One Biopharmaceuticals, Eli Lilly, Genmab, GlaxoSmithKline, Gilead, Kelun, Mersana, Sanofi, Roche, Pfizer, and Zymeworks.

Zymeworks, Ideaya and Biocytogen.

There are hundreds of ADCs in development, the vast majority of which are being developed for the treatment of cancer.

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Although there are currently no approved ADCs targeting PTK7, there are multiple PTK7 programs currently in, or about to begin, clinical development, including

• PRO1107, being developed by Genmab following its acquisition of ProfoundBio, is currently in Phase 1/2 with the first patient dosed in February 2024.

PRO1107 uses an MMAE payload, which is a tubulin inhibitor similar to the payload in Cofe-P, connected through a protease-cleavable hydrophilic linker system called LD343, and has a DAR of 8.

Unlike Cofe-P and PRO1107, DAY301 has a pure exatecan payload which may be associated with myelosuppression.

LY4175408, being developed by Eli Lilly, also has a pure exatecan payload.

We expect Eli Lilly will submit its IND in 2025.

• LY4175408, being developed by Eli Lilly, also has a pure exatecan payload and is being explored in a Phase 1 trial.

• SKB518, being developed by Kelun Biotech, is currently in Phase 1 in China.

• Additionally, there are multiple preclinical PTK7 bispecific ADCs in development, including the PTK7 x B7-H3 ADC recently acquired by IDEAYA Biosciences.

In addition, there are multiple PTK7 ADC programs that are projected to present clinical data in 2025 to 2027, which we believe will further validate our target and TOPO1 inhibitor payload approach.

Currently, there are no approved or actively developing ADCs targeting MUC16.

• KIVU-107, being developed by Kivu Bioscience, uses a pure exatecan payload and is being explored in a Phase 1 trial.

• IDE034, being developed by Ideaya Biosciences, an investigational PTK7/B7H3 bispecific TOP1 ADC being explored in a Phase 1 trial.

• Additionally, there are multiple preclinical PTK7 bispecific ADCs in development.

In addition, there are multiple PTK7 ADC programs that are projected to present clinical data in 2026 and 2027, which we believe will further validate our target and TOP1 inhibitor payload approach.

Currently, there are no approved ADCs targeting MUC16.

Regeneron is developing two MUC16 bispecific T cell-engaging antibodies;

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While several ADCs targeting other antigens in PROC are under development, none offer the combined advantages of high target expression in both depth and frequency, along with the potential for a matched blood-based biomarker like CA125.

Currently, ABBV-706 (developed by AbbVie) is the only clinical stage SEZ6 ADC in development.

ABBV-706 is a TOPO1 inhibitor-based ADC (DAR 6) with a cleavable linker.

In addition, there are several early-stage clinical trials evaluating CART cell therapies targeting MUC16.

Currently, we believe ABBV-706 (developed by AbbVie) is the only clinical stage SEZ6 ADC in development.

ABBV-706 is a TOP1 inhibitor-based ADC (DAR 6) with a cleavable linker.

In a Phase 1 trial in patients with SCLC and neuroendocrine neoplasms (“NEN”), ABBV-706 demonstrated 56% ORR in SCLC and 37% ORR in NENs.

ABBV-706 demonstrated a manageable safety profile with no on-target neurotoxicity.

The promising results with ABBV-706 validated SEZ6 as a target and demonstrated clinical improvement by switching to a cleavable TOPO1 inhibitor linker-payload.

The promising results with ABBV-706 validated SEZ6 as a target and demonstrated clinical improvement by switching to a cleavable TOP1 inhibitor linker-payload.

Manufacturing

We do not own or operate, and have no plans to establish, any manufacturing facilities.

Initially, we intend to continue to benefit from the continuity of partnership with WuXi Biologics and Hangzhou DAC for near-term IND-enabling studies and ADC manufacturing.

We continue to benefit from the continuity of partnership with WuXi Biologics and its affiliates and Hangzhou DAC for ADC manufacturing for our clinical supply pursuant to a master services agreement and material supply agreement, respectively, and corresponding work orders.

We will expand our CRDMO network as appropriate as our portfolio advances further in clinical trials.

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Multiple Phase 2 clinical trials may be conducted to obtain information prior to beginning larger and more expensive Phase 3 clinical trials.

The product candidate is administered to an expanded patient population to further evaluate dosage, to provide statistically significant evidence of clinical efficacy and to further test for safety, generally at multiple geographically dispersed clinical trial sites.

geographically dispersed clinical trial sites.

These clinical trials are intended to establish the overall risk/benefit ratio of the investigational product and to provide an adequate basis for product approval.

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Generally, pivotal studies are also Phase 3 studies but may be Phase 2 studies if the trial design provides a well-controlled and reliable assessment of clinical benefit, particularly in situations where there is an unmet medical need.

Post-approval trials,

sometimes referred to as Phase 4 clinical trials, may be conducted after initial marketing approval.

Post-approval trials, sometimes referred to as Phase 4 clinical trials, may be conducted after initial marketing approval.

These trials are used to gain additional experience from the treatment of patients in the intended therapeutic indication.

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Data obtained from clinical trials are not always conclusive and the FDA may interpret data differently than we interpret the same data.

Further, FDA’s “real time” release of newly issued Complete Response Letters associated with withdrawn or abandoned applications, if applicable to any of our product candidates, can materially impact our business and competitive advantage.

There is no assurance that the FDA will ultimately approve a drug product for marketing in the United States and we may encounter significant difficulties or costs during the review process.

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FDA Expedited Development and Review Programs

The FDA has various programs, including fast track designation, priority review, accelerated approval, and breakthrough therapy designation, which are intended to expedite or simplify the process for the development and FDA review of drugs that are intended for the treatment of serious or life-threatening diseases or conditions and demonstrate the potential to

address unmet medical needs.

The purpose of these programs is to provide important new drugs to patients earlier than under standard FDA review procedures.

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The FDA and other regulatory agencies have also required that companies enter into consent decrees or permanent injunctions under which specified promotional conduct is changed or curtailed.

However, companies may share truthful and not misleading information that is otherwise consistent with a product’s FDA-approved labelling.

However, companies may share truthful and not misleading information that is otherwise consistent with a

product’s FDA-approved labelling.

Modifications or enhancements to the drug or its labeling or changes of the site or process of manufacture are often subject to the approval of the FDA and other regulators, which may or may not be received or may result in a lengthy review process.

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Prescription Drug Marketing Act (“PDMA”), a part of the FDCA.

The Drug Supply Chain Security Act (“DSCSA”), enacted in 2013, aims to build an electronic system to identify and trace certain prescription drugs distributed in the U.S.

The DSCSA mandates phased-in and resource-intensive obligations for pharmaceutical manufacturers, wholesale distributors, and dispensers over a 10-year period that is expected to culminate in November 2023.

The law’s requirements include the quarantine and prompt investigation of a suspect product to determine if it is illegitimate and notifying trading partners and the FDA of any illegitimate product.

Drug manufacturers and their collaborators are also required to place a unique product identifier on prescription drug packages.

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It is unclear how future litigation, legislation, agency decisions, and administrative actions will impact the scope of the ODE.

The Consolidated Appropriations Act of 2026, signed into law in February 2026, codified this longstanding FDA interpretation of the Orphan Drug Act, allowing the FDA to approve multiple versions of the same orphan drug for different subindications and subpopulations.

In June 2024, in Loper Bright Enterprises v.

Raimondo , the U.S.

Supreme Court overruled the Chevron doctrine, which gives deference to regulatory agencies’ statutory interpretations in litigation against federal government agencies, such as

the FDA, where the law is ambiguous.

This landmark Supreme Court decision may invite various stakeholders to bring lawsuits against the FDA to challenge longstanding decisions and policies, such as market exclusivities, which could lead to uncertainties in the industry.

Further, changes in the leadership of the FDA and other federal agencies under the Trump administration may lead to new policies, changes in the regulations, or disruptions to the operations of federal agencies, any of which may impact our clinical development plans.

Supreme Court overruled the Chevron doctrine, which gave deference to regulatory agencies’ statutory interpretations in litigation against federal government agencies, such as the FDA, where the law is ambiguous.

This landmark Supreme Court decision may invite various stakeholders to bring lawsuits against the FDA to challenge longstanding decisions and policies, which could lead to uncertainties in the industry.

Further, changes in the leadership of the FDA and other federal agencies under the current administration may lead to new policies, changes in the regulations, or disruptions to the operations of federal agencies, any of which may impact our clinical development plans.

In the European Union, the European Commission, after receiving the opinion of the European Medicines Agency’s (“EMA”) Committee for Orphan Medicinal Products (“COMP”), grants orphan drug designation to also promote the development of products.

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Sales of our drugs will depend, in part, on the extent to which our drugs will be covered by third-party payors, such as government health programs, commercial insurers, and managed healthcare organizations, as well as the level of reimbursement such third-party payors provide for our products.

Patients and providers 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 in which our products are used.

Patients and providers 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 in which our products are used.

These third-party payors are increasingly reducing reimbursements for medical drugs and services.

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Private third-party payors tend to follow Medicare coverage and reimbursement limitations to a substantial degree, but also have their own methods and approval process apart from Medicare determinations.

Accordingly, decisions regarding the extent of coverage and amount of reimbursement to be provided for the ADC

Therapies will be made on a payor-by-payor basis.

Accordingly, decisions regarding the extent of coverage and amount of reimbursement to be provided for the ADC Therapies will be made on a payor-by-payor basis.

As a result, the coverage determination process may be a time-consuming and costly process that will require us to provide scientific and clinical support for the use of our products to each payor separately, with no assurance that coverage and adequate reimbursement will be obtained.

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However, any negotiated prices for our drugs covered by a Part D prescription drug plan will likely be lower than the prices we might otherwise obtain.

Moreover, while the MMA applies only to drug benefits for Medicare beneficiaries, private payors often follow Medicare coverage policy and payment limitations in setting their own payment rates.

Moreover, while the MMA applies only to drug benefits for Medicare beneficiaries, private payors often follow Medicare coverage policy and

payment limitations in setting their own payment rates.

Any reduction in payment that results from the MMA may result in a similar reduction in payments from non-governmental payors.

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The plan for the research was published in 2012 by the HHS, 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 are made to Congress.

It is also possible that comparative effectiveness research

demonstrating benefits in a competitor’s drug could adversely affect the sales of our ADC drug candidate.

It is also possible that comparative effectiveness research demonstrating benefits in a competitor’s drug could adversely affect the sales of our ADC drug candidate.

If third-party payors do not consider our drugs to be cost-effective compared to other available therapies, they may not cover our drugs as a benefit under their plans or, if they do, the level of payment may not be sufficient to allow us to sell our drugs on a profitable basis.

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These laws, and future state and federal healthcare reform measures, as discussed further below, may be adopted in the future, any of which may result in additional reductions in Medicare and other healthcare funding and otherwise affect the prices we may obtain for any product candidate for which it may obtain regulatory approval or the frequency with which any such product candidate is prescribed or used.

As noted above, the marketability of any products for wh ich we receive regulatory approval for commercial sale may suffer if the government and other third-party payors fail to provide adequate coverage and reimbursement.

As noted above, the marketability of any products for which we receive regulatory approval for commercial sale may suffer if the government and other third-party payors fail to provide adequate coverage and reimbursement.

We expect that an increasing emphasis on cost containment measures in the U.S.

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In addition, in order to be eligible to have its products paid for with federal funds under the Medicaid programs and purchased by certain federal grantees and agencies, a manufacturer also must participate in the Department of Veterans Affairs Federal Supply Schedule (“FSS”) pricing program, established by Section 603 of the Veterans Health Care Act of 1992.

Health Service, and the Coast Guard—that is at least 24% less than the Non-Federal Average Manufacturing Price for the prior fiscal year.

Under this program, the manufacturer is obligated to make products available for procurement on an FSS contract and charge a price to four federal agencies—the Department of Veterans Affairs, the Department of Defense, the Public Health Service, and the Coast Guard—that is at least 24% less than the Non-Federal Average Manufacturing Price for the prior fiscal year.

Since the enactment of the ACA, there have been judicial and Congressional challenges to certain aspects of the ACA.

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In January 2021, President Biden also issued an executive order to initiate a special enrollment period to allow people to obtain health insurance coverage through the ACA marketplace and instructs certain governmental agencies to review and reconsider their existing policies and rules that limit access to healthcare, among others.

We cannot predict how future litigation, healthcare reform measures of the Trump administration, or what other regulations will ultimately be implemented at the federal or state level, or the effect of any future legislation or regulation may have on our business.

We cannot predict how future litigation, healthcare reform measures of the current administration, or what other regulations will ultimately be implemented at the federal or state level, or the effect of any future legislation or regulation may have on our business.

Moreover, there has been heightened governmental scrutiny over the manner in which manufacturers set prices for their marketed products, which has resulted in several Congressional inquiries and proposed and enacted federal and state legislation designed to, among other things, bring more transparency to product pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for drug products.

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Raimondo , the U.S.

Supreme Court overruled the Chevron doctrine, which gives deference to regulatory agencies’ statutory interpretations in litigation against federal government agencies, such as the FDA, where the law is ambiguous.

There are important exemptions to Maximum Fair Price including medications that are orphan drug designated and approved, for only one rare disease, and drugs with low Medicare spend as defined by CMS.

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Various industry stakeholders have initiated lawsuits against the federal government asserting that the price negotiation provisions of the Inflation Reduction Act are unconstitutional.

Further, the current administration has issued executive orders focused on decreasing prescription drug prices, including directing the Secretary of HHS to establish a mechanism through which American patients can buy drugs directly from manufacturers who sell at a most-favored-nation price and directing the U.S.

Trade Representative and Secretary of Commerce to take action to ensure foreign countries are not engaged in practices that purposefully and unfairly undercut market prices and drive price hikes in the U.S.

In November 2025, CMS announced a voluntary initiative called the GENEROUS Model (GENErating cost Reductions fOr U.S.

Medicaid Model) to introduce the option of most-favored-nation pricing to the Medicaid program, whereby a drug manufacturer may voluntarily offer supplemental rebates to participating state Medicaid programs for a manufacturer’s covered outpatient drugs.

Government agreements with pharmaceutical companies and other measures that use most-favored-nation pricing targets for prescription drugs or that increase generic and biosimilar drug entry sooner than expected can have a material adverse effect on our industry, ability to set adequate pricing for new drugs to recover R&D costs, ability to attract potential investors and potential buyers in the future, or the pricing of our approved product in the U.S.

and in foreign countries.

The impact of these judicial challenges as well as future actions and agency rules implemented by the government on us and the pharmaceutical industry as a whole is unclear.

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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 drug manufacturer to make its drug products available to eligible patients as a result of the Right to Try Act, but the manufacturer must develop an internal policy and respond to patient requests according to that policy.

no obligation for a drug manufacturer to make its drug products available to eligible patients as a result of the Right to Try Act, but the manufacturer must develop an internal policy and respond to patient requests according to that policy.

Other Healthcare Laws

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Bribery Act of 2010, and other local anti-corruption laws that apply to our international activities;

• the federal Physician Payment Sunshine Act (“Open Payments”), and implementing regulations, which require applicable group purchasing organizations and manufacturers of covered drugs, medical devices, biologicals and medical supplies for which payment is available under Medicare, Medicaid, or the Children’s Health Insurance Program to report annually to the CMS information related to certain payments and other transfers of value made to covered recipients, including licensed physicians (defined to include doctors,

dentists, optometrists, podiatrists and chiropractors), certain non-physician healthcare professionals (such as physician assistants and nurse practitioners, among others), and teaching hospitals, and information regarding ownership and investment interests held by physicians and their immediate family members;

practitioners, among others), and teaching hospitals, and information regarding ownership and investment interests held by physicians and their immediate family members;

• analogous state and foreign law equivalents of each of the above federal laws, such as anti-kickback and false claims laws which may apply to items or services reimbursed by any third-party payor, including commercial insurers or patients;

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It was further amended and supplemented by the California Privacy Rights Act, which became effective on January 1, 2023, and imposes additional privacy and security obligations on companies doing business in California.

While there is currently an exception in the CCPA for protected health information that is subject to HIPAA and clinical trial regulations, as currently written, numerous other states have enacted legislation similar to the CCPA, and several states have enacted other privacy and security legislation, such as Washington’s My Health, My Data Act, which includes a private right of action.

The CCPA and such other new and evolving legislation may impact our business activities significantly, and these and other applicable state and foreign

privacy laws, as well as uncertain changes in future regulation and legislation, could impact our business strategies, increase our potential liability, increase our compliance costs, and adversely affect our business.

there is currently an exception in the CCPA for protected health information that is subject to HIPAA and clinical trial regulations, as currently written, numerous other states have enacted legislation similar to the CCPA, and several states have enacted other privacy and security legislation, such as Washington’s My Health, My Data Act, which includes a private right of action.

The CCPA and such other new and evolving legislation may impact our business activities significantly, and these and other applicable state and foreign privacy laws, as well as uncertain changes in future regulation and legislation, could impact our business strategies, increase our potential liability, increase our compliance costs, and adversely affect our business.

The collection and use of personal health data in the European Union are governed by the GDPR and applicable member state legislation.

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In such a case, the clinical trial cannot be conducted in that member state.

The Clinical Trials Regulation also aims to streamline and simplify the rules on safety reporting and introduces enhanced transparency requirements such as mandatory submission of a summary of the clinical trial results to the EU Database.

The Clinical Trials Regulation also aims to streamline and simplify the rules on safety

reporting and introduces enhanced transparency requirements such as mandatory submission of a summary of the clinical trial results to the EU Database.

European Drug Review and Approval

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There are a number of new marketing authorization routes available in the United Kingdom, Great Britain (England, Scotland and Wales) or Northern Ireland, in addition to the national procedure.

As with the EU position, a company can only start to market a medicine in the United Kingdom once it has received a marketing authorization.

As with the EU position, a company can only start to market a medicine in the United Kingdom once it has received a marketing

authorization.

The main legislation that applies to clinical trials in the United Kingdom is the United Kingdom Medicines for Human Use (Clinical Trials) Regulations 2004, which transposes the Clinical Trials Directive into domestic law.

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Employees and Human Capital

We have operated by leveraging skilled experts, consultants, contract research organizations, and contractors to manage our clinical operations, manufacturing, research and development, and other functions under the leadership and direction of our

We will continue to expand our infrastructure to manage our operations, including commercial with additional full-time employees.

As of December 31, 2025, we had 23 full-time or part-time employees.

Of these employees, 23 employees were engaged in research and development activities and 17 employees were engaged in selling, general and administrative activities.

In connection with the FYARRO Divestiture, 16 employees remained with Aadi Subsidiary, Inc., and 6 employees departed the company.

As a result, following the FYARRO Divestiture, we have 18 full-time or part-time employees.

None of our employees are represented by labor unions or covered by collective bargaining agreements.

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Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-K

Item 1. Business