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Item 9A. Controls and Procedures

2026-03-04 compared with 2025-03-05 · 100 added, 753 removed, 744 unchanged (53% of the section changed)

1 unchanged sentence

Evaluation of Disclosure Controls and Procedures

Our management, under the supervision and with the participation of our Principal Executive Officer (our Chief Executive Officer) and Principal Financial and Accounting Officer (our Chief Financial Officer), has evaluated the effectiveness of our disclosure controls and procedures as of period end.

Our management, under the supervision and with the participation of our Principal Executive Officer (our Chief Executive Officer) and Principal Financial Officer (our Chief Financial Officer), has evaluated the effectiveness of our disclosure controls and procedures as of period end.

The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended, or the Exchange Act, means controls and other procedures of a company that are designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported, within the time periods specified in the SEC’s rules and forms.

31 unchanged sentences

Directors, Executive Officers and Corporate Governance.

Information About Our Directors

The following table identifies our current directors and sets forth certain information regarding the members of our board of directors, including their ages as of February 28, 2025, and years of tenure on our board of directors.

Positions and Offices Held with TScan

Director Since

Stephen Biggar, M.D., Ph.D.

Gavin MacBeath, Ph.D.

Director, Chief Executive Officer

Katina Dorton, J.D., M.B.A.

Gabriela Gruia, M.D.

Barbara Klencke, M.D.

Garry Nicholson

The names and certain biographical information about our current directors, including each director’s business experience, director position held, information regarding involvement in certain legal or administrative proceeding, if applicable, and the director’s experiences, qualifications, attributes, or skills are set forth below.

Stephen Biggar, M.D., Ph.D.

has served as a member of our board of directors since March 2021.

Biggar is a partner at Baker Bros.

Advisors LP (“Baker Bros.”), a biotechnology-focused investment advisor.

Biggar joined Baker Bros.

in April 2000.

Biggar serves on the boards of Kiniksa Pharmaceuticals International, plc., Acadia Pharmaceuticals Inc., and Notch Therapeutics, Inc.

Biggar received an M.D.

in Immunology from Stanford University and received a B.S.

in Genetics from the University of Rochester.

We believe that Dr.

Biggar is qualified to serve as a member of our board of directors due to his extensive experience in the life sciences industry.

Gavin MacBeath, Ph.D.

has served as our Chief Executive Officer and as a member of our board of directors since May 2023.

He was previously our acting Chief Executive Officer from March 2023 to May 2023, and our Chief Scientific and Operating Officer from December 2018 to May 2023.

He has over two decades of experience in academia and industry, founding companies and driving research from early-stage discovery through drug approval.

Prior to joining TScan, Dr.

MacBeath served as the Chief Scientific Officer at Abpro Corporation from March 2017 to July 2018, where he advanced T cell-engaging bispecific antibodies through pre-clinical development.

Previously, Dr.

MacBeath served as Co-founder and SVP of Discovery at Merrimack Pharmaceuticals, Inc.

from February 2014 to October 2016.

MacBeath began his career in academia, where he served as the first fellow at Harvard’s Bauer Center for Genomics Research, as an Assistant Professor and later Associate Professor in the Department of Chemistry & Chemical Biology at Harvard University, and as Lecturer and Principal Investigator at Harvard Medical School.

MacBeath received his undergraduate degree from the University of Manitoba, his Ph.D.

from The Scripps Research Institute, and postdoctoral training with Dr.

Stuart Schreiber at Harvard University.

We believe that Dr.

MacBeath is qualified to serve on our board of directors because of the perspective and experience he provides as our Chief Executive Officer as well as his broad experience within the life sciences industry.

Katina Dorton, J.D., M.B.A.

has served as a member of our board of directors since March 2021.

Dorton also serves as a member of the board of directors, as chair of the audit committee, and as a member of the compensation and human capital management committee of Fulcrum Therapeutics, Inc., since January 2020, as a member of the board of directors, as chair of the audit committee, and as a member of the human resources and compensation committee of Mallinckrodt plc since February 2024.

In addition, Ms.

Dorton was a member of the board of directors of US Ecology, Inc., from 2014 to 2022 until its acquisition by Republic Services, Inc.

Dorton also served as a member of the board of directors and chair of the audit committee of Pandion Therapeutics, Inc., a biopharmaceutical company, from 2020 until its acquisition by Merck & Co., Inc., in 2021.

Previously, Ms.

Dorton held CFO positions at several biotechnology companies, including Nodthera Inc., a company developing medicines to inhibit the NLRP3 inflammasome from 2020 to 2022, Repare Therapeutics Inc., a synthetic lethality and DNA repair-focused oncology company from 2019 to 2020, AVROBIO, Inc., a lentiviral gene therapy company from 2017 through 2018, and Immatics GmbH, a biotechnology company from 2015 through 2017.

Earlier in her career, Ms.

Dorton served as a Managing Director in investment banking for Morgan Stanley and Needham & Company and as an attorney at Sullivan & Cromwell.

Dorton received her J.D.

from the University of Virginia School of Law, her M.B.A.

from George Washington University and her B.A.

from Duke University.

We believe that Ms.

Dorton is qualified to serve on our board of directors due to her extensive leadership experience in multiple publicly-traded and privately-held pharmaceutical and biotechnology companies, and expertise in developing, financing and providing executive leadership in numerous biopharmaceutical companies.

Keith Woods has served as a member of our board of directors since December 2023.

Woods has over three decades of experience in the biopharmaceutical sector, having served most recently as Chief Operating Officer of argenx U.S.

Inc., from April 2018 to June 2023, where he led the company through its transition from an R&D organization to a global commercial organization.

During this time, he oversaw key teams in preparation for argenx’s first product launch, including sales, marketing, market access and reimbursement, business operations, patient services and medical affairs.

Woods transitioned from this role to serve as a strategic commercial advisor to the board of directors of argenx.

Prior to argenx, Keith served as senior vice president of North American operations for Alexion Pharmaceuticals, Inc., where he managed a team of several hundred people in the U.S.

and Canada and was responsible for more than $1 billion in annual sales.

Prior to joining Alexion, Mr.

Woods held various positions of increasing responsibility within Roche, Amgen, and Eisai Co., Ltd., over a span of 20 years.

Keith currently serves on the board of directors of X4 Pharmaceuticals, Inc., Neurogene Inc., and Rocket Pharmaceuticals, Inc.

He holds a Bachelor of Science in marketing from Florida State University.

We believe that Mr.

Woods is qualified to serve on our board of directors because of his significant experience in commercialization, sales, global operations, supply chain, and business strategy in the life sciences industry.

Gabriela Gruia, M.D.

has served as a member of our board of directors since May 2021.

Gruia founded Gabriela Gruia Consulting, LLC in January 2021.

Prior to that, Dr.

Gruia served as the Chief Development Officer at Ichnos Sciences Inc.

from February 2020 to January 2021, where she oversaw several key functions including Regulatory Sciences, Clinical Operations, Clinical Pharmacology, Biostatistics and Drug Safety.

Prior to her time at Ichnos Sciences Inc., Dr.

Gruia served as Senior Vice President and Head of Regulatory Affairs for Novartis Oncology from February 2008 through February 2020, where she was responsible for leading the oncology regulatory affairs organization.

Gruia has served on the boards of directors for Aprea Therapeutics, Inc.

since 2023, Netris Pharma since 2023, and Molecular Templates, Inc.

from March 2022 until its dissolution in December 2024.

Gruia received her doctorate in medicine from Bucharest Medical School in Romania and has a Masters in Breast Pathology and Mammography from Rene Huguenin/Curie Institute Cancer Center in Paris, France.

She received her training in oncology and hematology from Rene Descartes University in Paris, France.

We believe that Dr.

Gruia is qualified to serve as a member of our board of directors due to her extensive leadership experience in the life sciences industry.

Barbara Klencke, M.D.

has served as a member of our board of directors since April 2023.

She also currently serves as an independent board member of Xencor since September 2023, ALX Oncology since January 2025, and Immune-Onc Therapeutics, Inc.

She has previously served as an independent board member of eFFECTOR Therapeutics, Inc.

from 2021 until 2024 and Lexent Bio from 2017 until that company’s acquisition by Foundation Medicine in 2020.

Klencke previously served as the Chief Medical and Chief Development Officer of Sierra Oncology Inc., a publicly traded clinical-stage biopharmaceutical company from 2015 until 2023 following its acquisition by GlaxoSmithKline plc in 2022.

From 2011 to 2015, Dr.

Klencke served as SVP, Global Development, at Onyx Pharmaceuticals, which was acquired by Amgen Inc., in 2013.

She also led a variety of both early- and late-stage oncology programs while at Genentech, Inc.

from 2003 to 2011.

She completed Internal Medicine and Hematology/Oncology training at the University of California, San Francisco and remained there as an Assistant Professor of Medicine in Oncology focusing on clinical research from 1995 to 2002.

Klencke holds a B.S.

from Indiana University and an M.D.

from the University of California, Davis.

We believe that Dr.

Klencke is qualified to serve as a member of our board of directors due to her significant scientific expertise in biotechnology.

Garry Nicholson has served as a member of our board of directors since June 2024.

Nicholson has more than 35 years of pharmaceutical and biotech oncology experience.

From August 2015 to November 2016, he served as President and Chief Executive Officer of XTuit Pharmaceuticals, where he also was a member of the board of directors.

Beginning in May 2008, he led the global oncology franchise at Pfizer until his departure in May 2015 as President, Pfizer Oncology.

His responsibilities included global commercialization and sales, clinical development and regulatory strategy, and business development.

Under his leadership, the company developed and launched Ibrance® (palbociclib), the first cyclin-dependent kinase (“CDK”) 4/6 inhibitor approved in the U.S.

During his tenure at Pfizer, Mr.

Nicholson served on the board of directors of the Pfizer Foundation and was a member of the company’s Portfolio, Strategy and Investment Committee, which set corporate research and development priorities and investment strategy.

Earlier in his career, Mr.

Nicholson held various leadership positions in the oncology division of Eli Lilly and Company.

In addition, he has served as an advisor to AMPATH, a consortium of North American universities and health centers, Moi University, Moi Teaching and Referral Hospital, and the Government of Kenya, which helps build sustainable healthcare systems in developing nations.

Nicholson began his career in healthcare as a pharmacy intern at Emory University.

He currently serves as chair of the board of directors at Abdera Therapeutics Inc., a privately held biopharmaceutical company and serves as chair of the board of directors of Day One Biopharmaceuticals, Inc., a publicly traded clinical and commercial stage biopharmaceutical company.

He also currently serves as a member of the board of directors at Avenzo Therapeutics, a privately held clinical stage company.

Nicholson previously served as a member of the board of directors of G1 Therapeutics, a commercial stage company, and of NextCure, Inc., a publicly traded clinical stage biopharmaceutical company, Turning Point Therapeutics, Inc., a publicly traded clinical stage precision oncology company, Five Prime Therapeutics, Inc., a publicly traded clinical stage pharmaceutical company, TESARO, Inc., a publicly traded oncology-focused biopharmaceutical company, Tmunity Therapeutics Inc., a privately held biotechnology company, SQZ Biotechnologies, Inc., a privately held biotechnology company and Personal Genome Diagnostics Inc., a privately held cancer genomics company.

Nicholson holds an M.B.A.

from the University of South Carolina and earned his B.S.

in Pharmacy at the University of

North Carolina at Chapel Hill.

We believe Mr.

Nicholson is qualified to serve as a member of our Board of Directors based on his significant experience in the life sciences, biotechnology and pharmaceutical industries and his knowledge of strategic and operational leadership priorities and corporate development matters.

There are no family relationships between or among any of our directors or executive officers.

The principal occupation and employment during the past five years of each of our directors was carried on, in each case except as specifically identified in this Annual Report on Form 10-K with a corporation or organization that is not a parent, subsidiary or other affiliate of us.

Except as described in “Item 10.

Directors, Executive Officers and Corporate Governance – Identifying and Evaluating Director Nominees,” there is no arrangement or understanding between any of our directors and any other person or persons pursuant to which he or she is to be selected as a director.

Executive Officers Who Are Not Directors

The following table identifies our executive officers, other than as otherwise noted above, and sets forth their current positions and years of tenure at TScan, their ages as of February 28, 2025, and certain other demographic information.

Positions and Offices Held with TScan

Officer Since

Chief Financial Officer and Treasurer

Zoran Zdraveski, J.D., Ph.D.

Chief Legal and Strategy Officer and Secretary

Chrystal Louis, M.D., M.P.H.

Chief Medical Officer

Amello has served as our Chief Financial Officer and Treasurer since January 2024.

Prior to joining TScan, from September 2022 to January 2024, Mr.

Amello was the Chief Financial Officer, Treasurer and Secretary at Candel Therapeutics, Inc.

Prior to Candel, Mr.

Amello served as Chief Financial Officer and Treasurer of Saniona AB from September 2020 to April 2022, and Senior Vice President, Chief Financial Officer and Treasurer of Akebia Therapeutics, Inc.

from September 2013 to August 2020.

Amello was also Executive Vice President, Chief Financial Officer and Treasurer of Alaunos Therapeutics, Inc.

(formerly known as ZIOPHARM Oncology, Inc.) from May 2012 to May 2013.

From April 2000 until June 2011, Mr.

Amello served in various positions of increasing responsibility at Genzyme Corporation (acquired by Sanofi), including Senior Vice President, Chief Accounting Officer and Corporate Controller, and also led the Strategic Financial Services group through which he served as a key advisor on all of Genzyme’s mergers and acquisitions and other strategic transactions, including the sale of the company to Sanofi.

Earlier in his career, Mr.

Amello spent ten years in the business advisory and assurance practice of Deloitte, serving in various roles of increasing responsibility through Senior Manager.

Since October 2017, Mr.

Amello served as a member of the Board of Directors of Acer Therapeutics, Inc.

until its acquisition by Zevra Therapeutics in November 2023 and was chairman of its audit committee.

Amello also served on the Board of Directors of New England Baptist Hospital from 2015 to 2023 and was chairman of the Quality of Care Committee and a member of the Finance and Investment Committee.

Amello received his B.S.

in accounting from Boston College and is a Certified Public Accountant in the Commonwealth of Massachusetts.

Zoran Zdraveski, J.D., Ph.D.

, has served as our Chief Legal and Strategy Officer and Secretary since September 2021.

He has more than 20 years of legal, IP and business operations experience in the biopharmaceutical industry.

Prior to joining TScan, from April 2017 to April 2021, Dr.

Zdraveski served as the Chief Legal and Technology Operations Officer at Magenta Therapeutics Inc., where he established the legal team and managed all aspects of legal, intellectual property and compliance both before and after Magenta’s 2018 initial public offering.

Prior to Magenta, he was the Vice President and Associate General Counsel at Epizyme Inc.

from July 2012 to April 2017.

Prior to joining Epizyme, he held patent counsel positions at Ironwood and Genzyme Therapeutics.

Zdraveski holds an M.S.

in Chemistry and a B.F.A.

in Art and Chemistry from Southern Methodist University, a J.D.

from Suffolk University Law School, and a Ph.D.

in Biochemistry from the Massachusetts Institute of Technology.

Chrystal Louis, M.D., M.P.H.

, has served as our Chief Medical Officer since April 2024.

Prior to joining TScan, from November 2022 to March 2024, Dr.

Louis was the SVP of hematology clinical development at Zentalis Pharmaceuticals, Inc.

Prior to Zentalis, Dr.

Louis served as VP, Head of Medical Affairs at CRISPR Therapeutics, Inc.

from July 2020 to November 2022.

From October 2016 to July 2020, Dr.

Louis served in various positions of increasing responsibility at Celgene Corporation (acquired by Bristol Myers Squibb Company), including Executive Director, Myeloid Diseases, U.S.

Medical Affairs, Executive Director, Oncology, U.S.

Medical Affairs and Executive Director, Pancreatic/GI Disease Lead, U.S.

Medical Affairs.

From September 2014 to October 2016, Dr Louis also served in the role of clinical development and project leadership strategy at Merrimack Pharmaceuticals, Inc.

Prior to joining industry, Dr.

Louis was an Assistant Professor at Texas Children’s Cancer Center and Hematology Service, Baylor College of Medicine, where she worked on the early development of CAR-T cell therapy products for solid tumor malignancies.

Louis received her M.D.

from Tulane University School of Medicine, her Masters Degree in Public Health from Tulane University School of Public Health and Tropical Medicine, and her B.A.

in Political Science and B.S.

in Chemistry from Southwestern University at Georgetown, TX.

The principal occupation and employment during the past five years of each of our executive officers was carried on, in each case except as specifically identified above, with a corporation or organization that is not a parent, subsidiary or other affiliate of us.

There is no arrangement or understanding between any of our executive officers and any other person or persons pursuant to which he was or is to be selected as an executive officer.

Board Committees

Our board of directors has established an audit committee, a compensation committee, a nominating and corporate governance committee, and a research and clinical development committee.

Each of the audit committee, compensation committee and nominating and corporate governance committee operates under a charter that satisfies the applicable standards of the SEC and Nasdaq.

Each such committee reviews its respective charter at least annually.

A current copy of the charter for each of the audit committee, compensation committee, nominating and corporate governance committee, and research and clinical development committee is posted on the corporate governance section of our website www.tscan.com .

Audit Committee

Katina Dorton, Gabriela Gruia, Barbara Klencke and R.

Keith Woods serve on the audit committee, which is chaired by Ms.

Our board of directors has determined that each member of the audit committee is “independent” for audit committee purposes as that term is defined by the rules of the SEC and Nasdaq, and that each has sufficient knowledge in financial and auditing matters to serve on the audit committee.

Our board of directors has designated Ms.

Dorton as an “audit committee financial expert,” as defined under the applicable rules of the SEC.

During the fiscal year ended December 31, 2024, the audit committee met five times.

The audit committee assists our board of directors with its oversight of the integrity of our financial statements;

our compliance with legal and regulatory requirements;

the qualifications, independence and performance of the independent registered public accounting firm;

the design and implementation of our risk assessment and risk management.

Among other things, our audit committee is responsible for reviewing and discussing with our management the adequacy and effectiveness of our disclosure controls and procedures.

The audit committee also discusses with our management and independent registered public accounting firm the annual audit plan and scope of audit activities, scope and timing of the annual audit of our financial statements, and the results of the audit, quarterly reviews of our financial statements and, as appropriate, initiates inquiries into certain aspects of our financial affairs.

Our audit committee is responsible for establishing and overseeing procedures for the receipt, retention and treatment of any complaints regarding accounting, internal accounting controls or auditing matters, as well as for the confidential and anonymous submissions by our employees of concerns regarding questionable accounting or auditing matters.

In addition, our audit committee has direct responsibility for the appointment, compensation, retention and oversight of the work of our independent registered public accounting firm.

Our audit committee has sole authority to approve the hiring and discharging of our independent registered public accounting firm, all audit engagement terms and fees and all permissible non-audit engagements with the independent auditor.

Our audit committee reviews and oversees all related person transactions in accordance with our policies and procedures.

All audit and non-audit services, other than de minimis non-audit services, to be provided to us by our independent registered public accounting firm must be approved in advance by our audit committee.

Compensation Committee

Stephen Biggar, Katina Dorton, Barbara Klencke and R.

Keith Woods serve on the compensation committee, which is chaired by Dr.

Our board of directors has determined that each member of the compensation committee is “independent” as defined in the applicable Nasdaq rules.

During the fiscal year ended December 31, 2024, the compensation committee met four times.

Our compensation committee assists our board of directors with its oversight of the forms and amount of compensation for our executive officers (including officers reporting under Section 16 of the Exchange Act), the administration of our compensation and equity and non-equity incentive plans for employees and other service providers and certain other matters related to our compensation programs.

The compensation committee, among other responsibilities, evaluates the performance of our chief executive officer and, in consultation with him, evaluates the performance of our other executive officers (including officers reporting under Section 16 of the Exchange Act).

Nominating and Corporate Governance Committee

Stephen Biggar, Katina Dorton and Gabriela Gruia serve on the nominating and corporate governance committee, which is chaired by Mr.

Our board of directors has determined that each member of the nominating and corporate governance committee is “independent” as defined in the applicable Nasdaq rules.

During the fiscal year ended December 31, 2024, the nominating and corporate governance committee held two meetings.

The nominating and corporate governance committee assists our board of directors with its oversight of and identification of individuals qualified to become members of our board of directors, consistent with criteria approved by our board of directors, and selects, or recommends that our board of directors selects, director nominees;

develops and recommends to our board of directors a set of corporate governance guidelines;

leads the annual performance review of the board of directors, its committees and management;

and oversees any related matters required by federal securities laws.

The nominating and corporate governance committee considers candidates for board membership suggested by its members and the chief executive officer.

Additionally, in selecting nominees for directors, the nominating and corporate governance committee will review candidates recommended by stockholders in the same manner and using the same general criteria as candidates recruited by the committee and/or recommended by our board of directors.

The nominating and corporate governance committee will also consider whether to nominate any person proposed by a stockholder in accordance with the provisions of our bylaws relating to stockholder nominations.

Research and Clinical Development Committee

Stephen Biggar, Gabriela Gruia, Barbara Klencke, Gavin MacBeath, and Garry Nicholson serve on the research and clinical development committee, which is chaired by Dr.

During the fiscal year ended December 31, 2024, the research and clinical development committee met five times.

Our research and clinical development committee assists our board of directors with its oversight of our research and clinical development activities and assists us in evaluating science and technology issues.

Identifying and Evaluating Director Nominees

Our board of directors is responsible for filling vacancies on our board of directors and for nominating candidates for election by our stockholders each year in the class of directors whose term expires at the relevant annual meeting.

The board of directors delegates the selection and nomination process to the nominating and corporate governance committee, with the expectation that other members of the board of directors, and of management, will be requested to take part in the process as appropriate.

Generally, the nominating and corporate governance committee identifies candidates for director nominees in consultation with management, through the use of search firms or other advisors, through the recommendations submitted by stockholders or through such other methods as the nominating and corporate governance committee deems to be helpful to identify candidates.

However, we do not have a formal policy concerning the diversity of the board of directors.

Once candidates have been identified, the nominating and corporate governance committee confirms that the candidates meet all of the minimum qualifications for director nominees established by the nominating and corporate governance committee.

The nominating and corporate governance committee may gather information about the candidates through interviews, detailed questionnaires, comprehensive background checks or any other means that the nominating and corporate governance committee deems to be appropriate in the evaluation process.

The nominating and corporate governance committee then meets as a group to discuss and evaluate the qualities and skills of each candidate, both on an individual basis and taking into account the overall composition and needs of our board of directors.

Based on the results of the evaluation process, the nominating and corporate governance committee recommends candidates for the board of directors’ approval to fill a vacancy or as director nominees for election to the board of directors by our stockholders each year in the class of directors whose term expires at the relevant annual meeting.

Although the nominating and corporate governance committee does not have a formal diversity policy and does not follow any ratio or formula with respect to diversity in order to determine the appropriate composition of the board of directors, the nominating and corporate governance committee and the full board of directors are committed to creating a board of directors with diversity, including diversity of expertise, experience, background, race and gender, and are committed to identifying, recruiting and advancing candidates offering such diversity in future searches.

Board and Committee Meeting Attendance

The full board of directors met four times during 2024.

During 2024, each member of the board of directors attended in person or participated in 75% or more of the aggregate of (i) the total number of meetings of the board of directors (held during the period for which such person has been a director), and (ii) the total number of meetings held by all committees of the board of directors on which such person served (during the periods that such person served), other than Timothy Barberich who did not attend any meetings of the board of directors during 2024 prior to his departure from the board of directors in June 2024.

Directors are responsible for attending the annual meeting of shareholders to the extent practicable.

Code of Business Conduct and Ethics

We have adopted a written code of conduct that applies to our directors, officers and employees, including our principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions.

A current copy of the code is posted on the corporate governance section of our website, which is located at https://ir.tscan.com/corporate-governance/governance-overview .

If we make any substantive amendments to, or grant any waivers from, the code of business conduct and ethics for any officer or director, we will disclose the nature of such amendment or waiver on our website or in a current report on Form 8-K.

Delinquent Section 16(a) Reports

Section 16(a) of the Exchange Act requires our directors and executive officers, and persons who beneficially own more than 10% of a registered class of our equity securities, to file with the SEC initial reports of ownership and reports of changes in ownership of our common stock and other equity securities.

Officers, directors and greater than 10% beneficial owners are required by SEC regulations to furnish us with copies of all Section 16(a) forms they file.

To our knowledge, based solely on our review of Forms 3, 4 and 5, and any amendments thereto, filed by such reporting persons and/or written representations that no Form 5 was required, we believe that during the fiscal year ended December 31, 2024, all filing requirements applicable to our executive officers, directors and persons who beneficially own more than 10% percent of a registered class of our equity securities under the Exchange Act were met in a timely manner except for one late Form 4 filing by each of Gavin MacBeath, Zoran Zdraveski and Leiden Dworak, in each case with respect to an award of stock options.

Compensation Recovery Policy

In accordance with the requirements of the SEC and Nasdaq listing rules, our board of directors adopted a compensation recovery policy on September 21, 2023, effective as of October 2, 2023.

The compensation recovery policy provides that in the event we are required to prepare a restatement of financial statements due to material noncompliance with any financial reporting requirement under securities laws, we will seek to recover any incentive-based compensation that was based upon the attainment of a financial reporting measure and that was received by any current or former executive officer during the three-year period preceding the date that the restatement was required if such compensation exceeds the amount that the executive officers would have received based on the restated financial statements.

We have filed this policy as an Exhibit to this Annual Report on Form 10-K.

Insider Trading Policy

We have adopted an insider trading policy that governs the purchase, sale, and/or other transactions of our securities by our directors, officers and employees that is reasonably designed to promote compliance with insider trading laws, rules and regulations, and any listing standards” that apply to us.

A copy of our insider trading policy is filed as Exhibit 19.1 to this Annual Report on Form 10-K.

In addition, with regard to our trading in our own securities, it is the our policy to comply with the applicable insider trading laws, rules and regulations, and any exchange listing standards when engaging in transactions in our securities.

Executive Compensation.

The information required by this Item 10 will be included in our definitive proxy statement to be filed with the Securities and Exchange Commission, or SEC, with respect to our 2026 Annual Meeting of Stockholders and is incorporated by reference.

We have adopted a Code of Business Conduct and Ethics for all of our directors, officers and employees as required by Nasdaq governance rules and as defined by applicable SEC rules.

Stockholders may locate a copy of our Code of Business Conduct and Ethics on our website at www.tscan.com.

Executive Compensation.

Our named executive officers for the fiscal year ended December 31, 2024, are:

• Gavin MacBeath, Ph.D., Chief Executive Officer and Director

Amello, Chief Financial Officer and Treasurer

• Chrystal Louis, M.D., M.P.H., Chief Medical Officer

Summary Compensation Table

The following table presents the compensation awarded to, earned by or paid to each of our named executive officers for the years indicated.

Name and Principal Position

Bonus ($) (5)

Option Awards ($) (1)

Non-Equity Incentive Plan Compensation ($) (2)

All Other Compensation ($) (3)

Gavin MacBeath, Ph.D.

Chief Executive Officer and Director

Chief Financial Officer and Treasurer

Chrystal Louis, M.D., M.P.H.

Chief Medical Officer

(1) The amounts reported represent the aggregate grant date fair value of the stock options awarded to the named executive officers during fiscal year 2024, calculated in accordance with ASC Topic 718.

Such grant date fair value does not take into account any estimated forfeitures.

The assumptions used in calculating the grant date fair value of the awards reported in this column are set forth in Note 6 to our financial statements for the year ended December 31, 2024, which are included in our Form 10-K filed with the SEC on March 5, 2025.

The amounts reported in this column reflect the accounting cost for the stock options and does not correspond to the actual economic value that may be received upon exercise of the stock option or any sale of any of the underlying shares of common stock.

(2) Represents performance-based cash bonuses awarded to our named executive officers.

See “Narrative Disclosures to the Summary Compensation Table -Non-Equity Incentive Plan Compensation” below for a description of this compensation.

(3) Amounts for 2024 represent matching 401(k) plan contributions.

Amello was appointed our Chief Financial Officer and Treasurer on January 29, 2024, and accordingly his 2024 base salary represents the amount paid from the commencement of his employment through December 31, 2024.

(5) Represents one-time signing bonuses paid to Mr.

Amello and Dr.

Louis in connection with the commencement of their employment.

Louis was appointed our Chief Medical Officer on April 8, 2024, and accordingly her 2024 base salary represents the amount paid from the commencement of her employment through December 31, 2024.

Narrative to Summary Compensation Table

Base salaries and annual incentive opportunities

The base salaries of all of our named executive officers are reviewed from time to time and adjusted when our board of directors or its compensation committee determines an adjustment is appropriate.

For our 2024 fiscal year, the base salary for Dr.

MacBeath, Mr.

Amello, and Dr.

Louis were $620,000, $500,000 and $495,000, respectively.

Each of our named executive officers is eligible to earn an incentive bonus each fiscal year, with such bonus awarded based on individual performance goals, as well as achievement of corporate goals related to our product development and advancement of pre-clinical studies established by our chief executive officer and approved by our board of directors.

During our fiscal year ended December 31, 2024, our named executive officers were eligible to earn cash incentive bonuses based on a combination of corporate and individual goals.

We require that participants continue to be employed through the payment date to receive a bonus.

For our 2024 fiscal year, Dr.

MacBeath, Mr.

Amello, and Dr.

Louis target annual bonuses as a percentage of base salary were 55%, 40% and 40%, respectively.

Pursuant to agreements with us, each of Dr.

MacBeath, Mr.

Amello, and Dr.

Louis are, eligible to receive certain acceleration benefits in the event of our change in control, as described in the footnotes to the “Outstanding equity awards at the year ended December 31, 2024” table and under the “Agreements with Our Named Executive Officers and Potential Payments upon Termination or Change of Control” section below.

Equity compensation

We offer stock options to our employees, including our named executive officers, as the long-term incentive component of our compensation program.

Our stock options allow our employees to purchase shares of our common stock at a price equal to the fair market value of our common stock on the date of grant.

Generally, our stock options granted to new hires have vested as to 25% of the total number of option shares on the first anniversary of the award and in equal monthly installments over the following 36 months.

Policy on the Timing of Awards of Options and Other Option-Like Instruments

We generally grant annual equity awards, including stock option grants to our named executive officers, in the first quarter of each fiscal year.

In addition, new hires receive equity grants at the time of their hiring.

During 2024, the compensation committee did not take into account any material nonpublic information when determining the timing and terms of equity incentive awards, and we did not time the disclosure of material nonpublic information for the purpose of affecting the value of executive compensation.

During 2024, we did not grant stock options to our named executive officers during any period beginning four business days before and ending one business day after the filing or furnishing of a Form 10-Q, 10-K or 8-K that discloses material nonpublic information.

Employee benefits and perquisites

Our named executive officers are eligible to participate in our health and welfare plans to the same extent as are full-time employees generally.

We generally do not provide our named executive officers with perquisites or other personal benefits.

Retirement benefits

We have established a 401(k) tax-deferred savings plan, which permits participants, including our named executive officers, to make contributions by salary deduction pursuant to Section 401(k) of the Internal Revenue Code.

We are responsible for administrative costs of the 401(k) plan.

We match 100% of every dollar contributed up to four percent of salary, subject to certain limitations under the Internal Revenue Code.

Outstanding equity awards at the year ended December 31, 2024

The following table sets forth information regarding each unexercised option and all unvested stock held by each of our named executive officers as of December 31, 2024.

Option Awards

Vesting Commencement Date

Number of securities underlying unexercised options exercisable (#) (1)

Number of securities underlying unexercised options unexercisable (#)

Option exercise price ($)

Option expiration date

Gavin MacBeath, Ph.D.

Chrystal Louis, M.D., M.P.H.

(1) Each of the option awards vest as follows:

25% of the shares vest on the first anniversary of the vesting commencement date, and 1/48th of the shares vest upon the completion of each month of continuous service thereafter.

Each executive is eligible to receive acceleration in the case of certain involuntary terminations that occur in connection with a change in control, as described under the “Agreements with Our Named Executive Officers and Potential Payments upon Termination or Change of Control” section below.

Employment agreements

Agreements with Our Named Executive Officers and Potential Payments upon Termination or Change of Control

We entered into employment agreements with each of our named executive officers, as summarized below.

The employment agreements provide for at-will employment and, other than in the context of a termination without cause or a resignation for good reason (as such terms are defined in the employment agreements), may be terminated at any time.

The severance and acceleration benefits that our named executive officers are entitled to are summarized below.

Agreements with Gavin MacBeath, Ph.D.

We entered into an employment agreement, effective as of April 23, 2021, with Dr.

MacBeath (the “2021 MacBeath Agreement”).

Pursuant to the terms of the employment agreement, Dr.

MacBeath received an annual base salary and is eligible to receive an incentive performance bonus of a specified percentage of his annual base salary, which bonus amount is determined by our board of directors and dependent on the achievement of specific company, team and individual performance objectives.

In addition, Dr.

MacBeath previously entered into our standard proprietary information and inventions agreement, which contains one-year post-termination non-solicitation and non-competition provisions, provided that such one-year period will automatically be extended for an additional year following the separation date if Dr.

MacBeath breaches a fiduciary duty to the Company or unlawfully takes, physically or electronically, any property belonging to the Company.

In the event of Dr.

MacBeath’s termination without cause or resignation for good reason in the three months prior to or 12 months following a change in control, then the restrictive covenants are no longer enforceable.

MacBeath was appointed as our acting Chief Executive Officer, effective as of March 28, 2023 and was later appointed as Chief Executive Officer, effective May 24, 2023.

In connection with such appointment, we entered into a new employment agreement (the “2023 MacBeath Agreement”), superseding the 2021 MacBeath Agreement.

The 2023 MacBeath Agreement provides Dr.

MacBeath with severance benefits if the Company terminates his employment without cause or resigns for good reason (as each such term is defined in the 2023 MacBeath Agreement), equal to (i) salary continuation at his base salary for eighteen months following the separation and (ii) payment of the employer share of COBRA premiums for up to eighteen months, subject to Dr.

MacBeath executing a general release of claims against the Company.

If such separation without cause or for good reason occurs within the three months prior or 12 months following a change of control, then Dr.

MacBeath will be entitled to a lump sum payment equal to (i) one-and-one-half (1.5) times his (x) base salary plus (y) annual target bonus, plus (ii) pro-rata target bonus and (iii) payment COBRA premiums for up to 18 months.

If the Company is subject to a change of control and in the three months prior or twelve months following Dr.

MacBeath is terminated without cause or resigns for good reason, then 100% of any unvested shares or equity awards shall immediately vest and be non-forfeitable.

The Company’s obligation to make severance payments during the applicable severance period will cease immediately upon Dr.

MacBeath’s material breach of his restrictive covenants as set forth in the Company’s standard proprietary information and inventions agreement.

Agreements with Jason A.

We entered into an employment agreement, effective as of January 29, 2024 with Mr.

Amello (the “Amello Employment Agreement”).

Pursuant to the terms of the Amello Employment Agreement, Mr.

Amello joined us as our Chief Financial Officer on January 29, 2024.

Amello is eligible to receive an annual base salary and is also eligible to receive an annual performance bonus of a specified percentage of his annual base salary, subject to his achievement of certain performance metrics to be approved and updated by our board of directors on an annual basis.

Amello also received a one-time signing bonus of $60,000.

In the event Mr.

Amello leaves within 12 months of receiving such bonus (other than due to a termination without cause or a resignation for good reason (as each such term is defined in the Amello Employment Agreement)), Mr.

Amello will be required to repay such signing bonus.

The employment agreement also provides Mr.

Amello with severance benefits if the Company terminates his employment without cause or if Mr.

Amello resigns for good reason equal to (i) salary continuation at his base salary for 12 months following the separation and (ii) COBRA premiums coverage for up to 12 months.

If such separation without cause or for good reason occurs in the three months prior to a change of control or within 12 months at or following a change of control, then Mr.

Amello will be entitled to (i) a lump sum cash payment equal to one times (x) his base salary plus (y) his annual target bonus, (ii) his pro rata target bonus for the number of days worked in the fiscal year of such separation, (iii) COBRA premiums coverage for up to 12 months and (iv) accelerated vesting of all unvested stock option and equity awards.

Such severance payments and benefits are conditioned upon Mr.

Amello executing a general release of all claims that he may have against the Company.

The Company’s obligation to make severance payments during the applicable severance period will cease immediately upon Mr.

Amello’s material breach of the proprietary information and inventions agreement between him and the Company.

Amello also entered into our standard proprietary information and inventions agreement, which contains one-year post-termination non-solicitation and non-competition provisions, provided that such one-year period will automatically be extended for an additional one year if Mr.

Amello engages in any activity in violation of such provisions.

Agreements with Chrystal Louis, M.D., M.P.H.

We entered into an employment agreement, effective as of April 4, 2024 with Dr.

Louis (the “Louis Employment Agreement”).

Pursuant to the terms of the Louis Employment Agreement, Dr.

Louis joined us as our Chief Medical Officer on April 4, 2024.

Louis is eligible to receive an annual base salary and is also eligible to receive an annual performance bonus of a specified percentage of her annual base salary, subject to her achievement of certain performance metrics to be approved and updated by our board of directors on an annual basis.

Louis also received a one-time signing bonus of $45,000.

In the event Dr.

Louis leaves within 12 months of receiving such bonus, Dr.

Louis will be required to repay such signing bonus.

The employment agreement also provides Dr.

Louis with severance benefits if the Company terminates her employment without cause or if Dr.

Louis resigns for good reason (as each such term is defined in the Louis Employment Agreement) equal to (i) salary continuation at her base salary for 12 months following the separation (plus her full target bonus for the prior fiscal year, to the extent not yet paid) and (ii) COBRA premiums coverage for up to 12 months.

If such separation without cause or for good reason occurs in the three months prior to a change of control or within 12 months at or following a change of control, then Dr.

Louis will be entitled to (i) a lump sum cash payment equal to one times (x) her base salary plus (y) her annual target bonus, (ii) her pro rata target bonus for the number of days worked in the fiscal year of such separation, and (iii) accelerated vesting of all unvested stock option and equity awards.

Such severance payments and benefits are conditioned upon Dr.

Louis executing a general release of all claims that she may have against the Company.

The Company’s obligation to make severance payments during the applicable severance period will cease immediately upon Dr.

Louis’s material breach of the proprietary information and inventions agreement between her and the Company.

Equity Plan Compensation Information

The following table provides information as of December 31, 2024 with respect to the shares of our common stock that may be issued under our existing equity compensation plans.

Equity Compensation Plan Information

Plan Category

Number of securities to be issued upon exercise of outstanding options, warrants and rights

Weighted average exercise price of outstanding options, warrants and rights

Number of securities remaining available for future issuance under equity compensation plan (excluding securities in first column

Equity compensation plan approved by security holders (1)(2)

Equity compensation plan not approved by security holders

(1) Includes the following plans:

our 2018 Equity Incentive Plan (the “2018 Plan”), our 2021 Equity Incentive Plan (as amended, the “2021 Plan”) and our 2021 Employee Stock Purchase Plan (the “2021 ESPP”).

(2) As of December 31, 2024, a total of 5,781,492 shares of our common stock have been reserved for issuance pursuant to the 2021 Plan which number excludes the 5,187,142 shares that were added to the plan as a result of the automatic annual increase on January 1, 2025.

The 2021 Plan provides that the number of shares reserved and available for issuance under the plan will automatically increase each January 1, beginning on January 1, 2022, by four percent of the total outstanding common shares on the immediately preceding December 31 or such number of shares as determined by our board of directors.

This number will be subject to adjustment in the event of a stock split, stock dividend or other change in our capitalization.

The shares of common stock underlying any awards that are forfeited, cancelled, held back upon exercise or settlement of an award to satisfy the exercise price or tax withholding, reacquired by us prior to vesting, satisfied without the issuance of stock, expire or are otherwise terminated, other than by exercise, under the 2021 Plan and the 2018 Plan will be added back to the shares of common stock available for issuance under the 2021 Plan.

The Company no longer makes grants under the 2018 Plan.

As of December 31, 2024, a total of 985,486 shares of our common stock have been reserved for issuance pursuant to the 2021 ESPP, which number excludes the 565,906 shares that were added to the plan as a result of the automatic annual increase on January 1, 2025.

The 2021 ESPP provides that the number of shares reserved and available for issuance under the plan will automatically increase each January 1, beginning on January 1, 2022, by the lesser of one percent of the outstanding number of shares of our common stock on the immediately preceding December 31 or such number of shares as determined by our board of directors.

This number will be subject to adjustment in the event of a stock split, stock dividend or other change in our capitalization.

Non-Employee Director Compensation

Our board of directors adopted and maintains a non-employee director compensation policy, which is designed to enable us to attract and retain, on a long-term basis, highly qualified non-employee directors.

Under the policy, each director who is not an employee is paid cash and equity compensation.

The fees paid to non-employee directors for service on the board of directors and for service on each committee of the board of directors on which the director is a member are as follows:

Member Annual Fee ($)

Chairperson Additional Annual Fee ($)

Board of Directors

Audit Committee

Compensation Committee

Research and Clinical Development Committee

Nominating and Corporate Governance Committee

We also reimburse our non-employee directors for reasonable travel and out-of-pocket expenses incurred in connection with attending our board of director and committee meetings.

In addition, each new non-employee director elected to our board of directors will be granted an option to purchase up to 47,500 shares of our common stock on the date of such director’s election or appointment to the board of directors, which will vest in the following manner, subject to the director’s continued service on our board of directors through such vesting date:

in full upon the earlier to occur of the first anniversary of the date of grant or the date of the next annual meeting.

On the date of each annual meeting of stockholders of our company, each non-employee director will be granted an additional option to purchase 47,500 shares of our common stock, which will vest in the following manner, subject to the director’s continued service on our board of directors through such vesting date:

in full upon the earlier to occur of the first anniversary of the date of grant or the date of the next annual meeting.

Director Compensation Table

The table below shows all compensation earned by or paid to our non-employee directors during 2024.

Fees earned or paid in cash ($)

Option awards ($) (1)(2)

All other compensation ($)

Stephen Biggar, M.D., Ph.D.

Katina Dorton, J.D., M.B.A.

Gabriela Gruia, M.D.

Barbara Klencke, M.D.

Garry Nicholson

Timothy Barberich (3)

(1) The amounts in this column represent the aggregate grant date fair value of option awards granted to the non-employee director in the applicable fiscal year computed in accordance with FASB ASC Topic 718.

See Note 6 to our financial statements for the year ended December 31, 2024, which are included in this Form 10-K.

See Note 6 of the notes to our consolidated financial statements appearing in this Form 10-K for a discussion of our assumptions made in determining the grant date fair value of our equity awards.

(2) As of December 31, 2024, our non-employee directors held outstanding stock options as follows:

Biggar (options to purchase 91,646 shares), Ms.

Dorton (options to purchase 140,426 shares), Dr.

Gruia (options to purchase 109,938 shares), Dr.

Klencke (options to purchase 93,170 shares), Mr.

Woods (options to purchase 65,000 shares) and Mr.

Nicholson (options to purchase 71,250 shares).

Barberich did not hold any outstanding options or unvested shares.

Barberich resigned from the board of directors effective June 12, 2024.

The information required by this Item 11 will be included in our definitive proxy statement to be filed with the SEC, with respect to our 2026 Annual Meeting of Stockholders and is incorporated by reference.

Sec urity Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters.

The following table sets forth information, to the extent known by us or ascertainable from public filings, with respect to the beneficial ownership of our common stock as of February 28, 2025, by:

• each of our directors;

• each of our named executive officers;

• all of our directors and executive officers as a group;

• each person, or group of affiliated persons, who is known by us to beneficially own more than five percent of our voting common stock.

The column entitled “Percentage of Shares Beneficially Owned” is based on a total of 52,314,039 shares of our voting common stock outstanding as of February 28, 2025.

Beneficial ownership is determined in accordance with the rules and regulations of the SEC and includes voting or investment power with respect to our voting common stock.

Shares of our voting common stock subject to options that are currently exercisable or exercisable within 60 days of February 28, 2025 are considered outstanding and beneficially owned by the person holding the options for the purpose of calculating the percentage ownership of that person but not for the purpose of calculating the percentage ownership of any other person.

Except as otherwise noted, the persons and entities in this table have sole voting and investing power with respect to all of the shares of our common stock beneficially owned by them, subject to community property laws, where applicable.

Except as otherwise indicated in the table below, addresses of named beneficial owners are in care of TScan Therapeutics, Inc., 830 Winter Street, Waltham, MA 02451.

Name of Beneficial Owner

Shares Beneficially Owned

Percentage of Shares Beneficially Owned

Greater-than-five Percent Stockholders:

Entities affiliated with Lynx1 Capital Management, L.P.

Entities affiliated with EcoR1 Capital, LLC (2)

Entities affiliated with BlackRock, Inc.

Entities affiliated with Biotechnology Value Fund, L.P.

Entities affiliated with K2 HealthVentures Equity Trust LLC (5)

Entities affiliated with Adage Capital Partners, L.P.

Entities affiliated with Baker Bros.

Advisors, L.P.

Named Executive Officers and Directors:

Gavin MacBeath, Ph.D., Chief Executive Officer and Director (8)

Amello, Chief Financial Officer and Treasurer (9)

Chrystal Louis, M.D., M.P.H., Chief Medical Officer (10)

Stephen Biggar, M.D., Ph.D., Director (11)

Katina Dorton, J.D., M.B.A., Director (12)

Gabriela Gruia, M.D., Director (13)

Barbara Klencke, Director (14)

Keith Woods, Director (15)

Garry Nicholson, Director

All current executive officers and directors as a group (10 persons) (16)

* Represents beneficial ownership of less than one percent.

(1) Information herein is based solely on a Schedule 13G/A filed by Lynx1 Capital Management LP (“Lynx1”) and Weston Nichols with the SEC on February 14, 2025.

Consists of 5,357,347 shares of voting common stock held by Lynx1.

Lynx1 is the investment manager to Lynx1 Master Fund LP (“Lynx1 Fund”), with respect to the shares of voting common stock directly held by the Lynx1 Fund.

Weston Nichols is the sole member of Lynx1 Capital Management GP LLC, the general partner of Lynx1, with respect to the shares of voting common stock directly held by Lynx1 Fund.

Nichols shares voting and investment power over the shares held by Lynx1 Fund and as a result may be deemed to have beneficial ownership of such shares.

The address for the foregoing persons is c/o Lynx1, 151 Calle de San Francisco, Suite 200, PMB 1237, San Juan, PR 00901-1607.

(2) Information herein is based solely on a Schedule 13G filed by EcoR1 Capital, LLC (“EcoR1”) and EcoR1 Capital Fund Qualified, L.P.

(“Qualified Fund”) and Oleg Nodelman (collectively, the “EcoR1 Filers”) with the SEC on June 5, 2023.

Consists of 5,000,000 shares of voting common stock.

EcoR1 is the general partner and investment adviser of investment funds, including Qualified Fund.

Nodelman is the control person of EcoR1.

Qualified Fund filed this Schedule 13G on June 5, 2023 jointly with the other Filers, but not as a member of a group and it expressly disclaims membership in a group.

Such filing should not be construed as an admission that it is, and it disclaims that it is, a beneficial owner, as defined in Rule 13d-3 under the Act, of any of the shares of voting common stock covered by this Schedule 13G.

Each Filer also disclaims beneficial ownership of the Stock except to the extent of that person’s pecuniary interest therein.

The address of the EcoR1 Filers is 357 Tehama Street #3, San Francisco, CA 94103.

(3) Information herein is based solely on a Schedule 13G filed by BlackRock, Inc.

(“BlackRock”) with the SEC on November 8, 2024.

Consists of 4,633,276 shares of voting common stock, for which BlackRock has sole voting power and sole dispositive power.

The address of BlackRock is 50 Hudson Yards, New York, NY 10001.

(4) Information herein is based solely on a Schedule 13G filed by Biotechnology Value Fund, L.P.

(“BVF”), Biotechnology Value Trading Fund OS LP (“Trading Fund OS”), BVF I GP LLC (“BVF GP”), BVF GP Holdings LLC (“BVF GPH”), Biotechnology Value Fund II, L.P.

(“BVF2”), BVF Partners L.P.

(“Partners”), BVF II GP LLC (“BVF2 GP”), BVF Inc., BVF Partners OS Ltd (“Partners OS”) and Mark N.

Lampert with the SEC on November 14, 2024.

Consists of (i) 3,681,509 shares of voting common stock held by BVF, including 2,083,529 shares of voting common stock underlying certain pre-funded warrants held by it, (ii) 1,210,605 shares of voting common stock held by BVF2, (iii) 140,576 shares of voting common stock held by Trading Fund OS and (iv) 40,313 shares of voting common stock held by a certain Partners managed account (“Partners Managed Account”).

These amounts exclude (i) 4,289,365 shares of voting common stock issuable upon the exercise of pre-funded warrants held by BVF, (ii) 4,983,846 shares of voting common stock issuable upon the exercise of pre-funded warrants held by BVF2, (iii) 503,238 shares of voting common stock issuable upon the exercise of pre-funded warrants held by Trading Fund OS and (iv) 200,548 shares of voting common stock issuable upon the exercise of pre-funded warrants held by Partners Managed Account, which pre-funded warrants may not be exercised if, upon giving effect to such exercise, would cause the aggregate number of shares of voting common stock beneficially owned by such holder (together with its affiliates and other attribution parties) to exceed 4.99% of the number of shares of voting common stock of the Company that would be outstanding immediately after giving effect to the exercise.

The holders of pre-funded warrants may increase or decrease such beneficial ownership limitation percentage not in excess of 19.99% by providing the Company with at least 61 days’ prior notice of any increase.

BVF GP, as the general partner of BVF, may be deemed to beneficially own the 3,681,509 shares of voting common stock and beneficially owned and 4,289,365 shares of voting common stock issuable upon the exercise of pre-funded warrants held by BVF.

BVF2 GP, as the general partner of BVF2, may be deemed to beneficially own the 1,210,605 shares of voting common stock beneficially owned and 4,983,846 shares of voting common stock issuable upon the exercise of pre-funded warrants held by BVF2.

Partners OS, as the general partner of Trading Fund OS, may be deemed to beneficially own the 140,576 shares of voting common stock beneficially owned and 503,238 shares of voting common stock issuable upon the exercise of pre-funded warrants held by Trading Fund OS.

BVF GPH, as the sole member of each of BVF GP and BVF2 GP, may be deemed to beneficially own the 4,892,114 shares of voting common stock beneficially owned in the aggregate by BVF and BVF2.

Partners, as the investment manager of BVF, BVF2 and Trading Fund OS, and the sole member of Partners OS, may be deemed to beneficially own 5,073,003 shares of voting common stock beneficially owned in the aggregate by BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account, including 40,313 shares of voting common stock in the Partners Managed Account and excluding 200,548 shares of voting common stock issuable upon the exercise of pre-funded warrants held in the Partners Managed Account.

BVF Inc., as the general partner of Partners, may be deemed to beneficially own the 5,073,003 shares of voting common stock beneficially owned by Partners.

Lampert, as a director and officer of BVF Inc., may be deemed to beneficially own the 5,073,003 shares of voting common stock beneficially owned by BVF Inc.

BVF GP, BVF GPH, Partners, BVF Inc.

Lampert share voting and dispositive power over the shares of voting common stock beneficially owned by BVF.

BVF GPH, Partners, BVF Inc.

Lampert share voting and dispositive power over the shares of voting common stock beneficially owned by BVF2.

Partners, BVF Inc.

Lampert share voting and dispositive power over the shares of voting common stock beneficially owned by Trading Fund OS and held in the Partners Managed Account.

BVF GP disclaims beneficial ownership of the shares of voting common stock beneficially owned by BVF.

BVF2 GP disclaims beneficial ownership of the shares of voting common stock beneficially owned by BVF2.

Partners OS disclaims beneficial ownership of the shares of voting common stock beneficially owned by Trading Fund OS.

BVF GPH disclaims beneficial ownership of the shares of voting common stock beneficially owned by BVF and BVF2.

Each of Partners, BVF Inc.

Lampert disclaims beneficial ownership of the shares of voting common stock beneficially owned by BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account.

The business address of BVF, BVF GP, BVF2, BVF2 GP, BVF GPH, Partners, BVF Inc., Mr.

Lampert and Dr.

Hrustanovic is 44 Montgomery St., 40th Floor, San Francisco, California 94104.

The business address of Trading Fund OS and Partners OS is PO Box 309 Ugland House, Grand Cayman, KY1-1104, Cayman Islands.

(5) Information herein is based solely on a Schedule 13G/A filed by K2 HealthVentures Equity Trust LLC (“K2HV”), Parag Shah and Anup Arora with the SEC on February 14, 2025.

Consists of 3,602,700 shares of voting common stock held directly by K2HV.

K2HV is an investment vehicle for holding equity securities and may be deemed to directly beneficially own the shares of voting common stock that it holds directly and has the right to acquire within 60 days upon conversion of the convertible term loans.

Arora serve as the managing members of K2HV and, in such capacities, may be deemed to indirectly beneficially own the shares of voting common stock that K2HV holds directly.

The address for the above referenced entities and individuals is 855 Boylston Street, 10th Floor, Boston, MA 02116.

(6) Information herein is based solely on a Schedule 13G/A filed by Adage Capital Partners, L.P.

(“ACP”), Adage Capital Partners GP, L.L.C.

(“ACPGP”), Adage Capital Management, L.P.

(“ACM”), Robert Atchinson and Phillip Gross with the SEC on February 7, 2024.

Consists of 3,900,000 shares of voting common stock directly owned by ACP.

ACPGP is the general partner of ACP.

ACM is the investment manager of ACP.

Adage Capital Advisors, L.L.C.

(“ACA”) is managing member of ACPGP.

Adage Capital Partners LLC (“ACPLLC”) is general partner of ACM.

Robert Atchinson and Phillip Gross are managing members

of ACA and ACPLLC.

Robert Atchinson and Phillip Gross may be deemed to shared voting and dispositive power over the shares held directly by ACP.

The principal address of each reporting person is 200 Clarendon Street, 52nd Floor, Boston, Massachusetts 02116.

(7) Information herein is based solely on a Schedule 13D/A filed by Baker Bros.

Advisors LP (“BBA”), Baker Bros.

Advisors (GP) LLC (“BBA-GP”), Felix J.

Baker and Julian C.

Baker with the SEC on April 23, 2024.

Consists of (i) 256,209 shares of voting common stock held by 667, L.P.

(“667”) and (ii) 2,528,583 shares of voting common stock held by Baker Brothers Life Sciences, L.P.

(“Baker Life Sciences” and together with 667, the “BBA Funds”).

These amounts exclude (i) 4,018,678 shares of voting common stock issuable upon exercise of pre-funded warrants held by 667 and (ii) 43,158,741 shares of voting common stock issuable upon the exercise of pre-funded warrants held by Baker Life Sciences.

The pre-funded warrants held by the BBA Funds are only exercisable to the extent that after giving effect to such exercise the holders thereof, together with their affiliates and any members of a Section 13(d) group with such holders, would beneficially own, for purposes of Rule 13d-3 under the Securities Exchange Act of 1934, as amended, no more than 4.99% of the outstanding shares of voting common stock of the Company (the “Maximum Percentage”).

By written notice to the Company, the BBA Funds may from time to time increase or decrease the Maximum Percentage applicable to that BBA Fund to any other percentage not in excess of 19.99%.

Any such increase will not be effective until the 61st day after such notice is delivered to the Company.

As a result of this restriction, the number of shares that may be issued upon exercise of the pre-funded warrants by the BBA Funds may change depending upon changes in the number of outstanding shares of voting common stock of the Company.

The pre-funded warrants held by the BBA Funds are not currently exercisable due to the effect of the Maximum Percentage.

The BBA-GP is the sole general partner of the Adviser.

Pursuant to management agreements, as amended, among BBA-GP, Baker Life Sciences, and 667, and their respective general partners, the BBA Funds’ respective general partners relinquished to BBA-GP all discretion and authority with respect to the investment and voting power of the securities held by the BBA Funds, and thus BBA-GP has complete and unlimited discretion and authority with respect to the BBA Funds’ investments and voting power over investments.

BBA-GP, Felix J.

Baker and Julian C.

Baker as management members of the BBA-GP, and the BBA may be deemed to be beneficial owners of the securities of the Company held by the Funds.

The address for the above referenced entities and individuals is 860 Washington Street, 3rd Floor, New York, NY 10014.

(8) Consists of (i) 49,767 shares of voting common stock held by Dr.

MacBeath and (ii) 936,222 shares of voting common stock subject to options held by Dr.

MacBeath that are vested and exercisable within 60 days of February 28, 2025.

(9) Consists of 234,375 shares of voting common stock subject to options held by Mr.

Amello that are vested and exercisable within 60 days of February 28, 2025.

(10) Consists of 95,000 shares of voting common stock subject to options held by Dr.

Louis that are vested and exercisable within 60 days of February 28, 2025.

(11) Consists of 44,146 shares of voting common stock subject to options held by Dr.

Biggar that are vested and exercisable within 60 days of February 28, 2025.

(12) Consists of 92,926 shares of voting common stock subject to options held by Ms.

Dorton that are vested and exercisable within 60 days of February 28, 2025.

(13) Consists of 62,438 shares of voting common stock subject to options held by Dr.

Gruia that are vested and exercisable within 60 days of February 28, 2025.

(14) Consists of (i) 45,000 shares of voting common stock held by and 42,621 shares of voting common stock subject to options held by Dr.

Klencke that are vested and exercisable within 60 days of February 28, 2025 and (ii) 25,000 shares of voting common stock held by the Klencke Huestis Trust, for which Dr.

Klencke serves as co-trustee along with her spouse.

(15) Consists of 17,500 shares of voting common stock subject to options held by Dr.

Woods that are vested and exercisable within 60 days of February 28, 2025.

(16) Consists of (i) 124,483 shares of voting common stock and (ii) 1,746,634 shares of voting common stock underlying options that are vested and exercisable within 60 days of February 28, 2025.

The information required by this Item 12 will be included in our definitive proxy statement to be filed with the SEC, with respect to our 2026 Annual Meeting of Stockholders and is incorporated by reference.

C ertain Relationships and Related Transactions, and Director Independence.

Other than the compensation agreements and other arrangements described under “Executive compensation” and “Director compensation” in this Form 10-K and the transactions described below, since January 1, 2023, there has not been and there is not currently proposed, any transaction or series of similar transactions to which we were, or will be, a party in which the amount involved exceeded, or will exceed, $120,000 (or, if less, 1% of the average of our total assets amounts at December 31, 2023 and 2024) and in which any director, executive officer, holder of five percent or more of any class of our capital stock or any member of the immediate family of, or entities affiliated with, any of the foregoing persons, had, or will have, a direct or indirect material interest.

Agreements with Our Stockholders

In connection with our preferred stock financings prior to our IPO, we entered into an investors’ rights agreement, voting agreement, right of first refusal agreement and product interest rights agreement, in each case, with the purchasers of our preferred stock and certain holders of our common stock.

All of the material provisions of these agreements terminated immediately prior to the completion of our IPO, other than the provisions relating to registration rights, which continued in effect following the completion of our IPO and entitle the holders of such rights to demand that we file a registration statement, subject to certain limitations, and to request that their shares be covered by a registration statement that we are otherwise filing.

Such provisions relating to registration rights terminated on July 20, 2024.

Nominating Rights and Registration Rights Agreements with the BBA Funds

In connection with our Series C convertible preferred stock financing, we entered into a nominating agreement (the Nominating Agreement) with Baker Brothers Life Sciences, L.P.

and 667, L.P.

(collectively, the “BBA Funds”) which was subsequently amended and restated on April 22, 2021, pursuant to which, among other things, we agreed to support the nomination of, and cause our board of directors (or the nominating committee thereof) to include in the slate of nominees recommended to our stockholders for election as directors at each annual or special meeting of our stockholders at which directors are to be elected, one person designated from time to time by the BBA Funds, subject to the requirements of fiduciary duties under applicable law and the terms and conditions of the Nominating Agreement.

The agreement only applies during the period beginning at the closing of our IPO and for the three years thereafter, as long as (1) the BBA Funds and their affiliates, collectively, beneficially own at least 75% of the Series C convertible preferred stock purchased by the BBA Funds in such Series C convertible preferred stock financing, or such number of shares of our common stock issued upon conversion of such number of shares of Series C convertible preferred stock (in either case, as adjusted for any stock split, stock dividend, combination, or other recapitalization or reclassification or similar transaction), and (2) the BBA Funds and their affiliates, collectively, beneficially own at least two percent of our then outstanding voting common stock.

Our obligations under the Nominating Agreement terminated on July 20, 2024.

Also in connection with our Series C convertible preferred stock financing, we entered into a Registration Rights Agreement with the BBA Funds, pursuant to which, among other things, we agreed to provide the BBA Funds with certain “resale” registration rights and related “piggy-back” rights.

Registration Rights with K2 Health Ventures

On September 9, 2022, we entered into a Loan and Security Agreement (the K2HV Loan Agreement) with K2 Health Ventures LLC (K2HV) pursuant to which K2HV may provide us with convertible term loans in an aggregate principal amount of up to $60.0 million, of which $30.0 million was fully funded at the closing date in September 2022.

On November 20, 2024, K2HV converted $15.0 million of the outstanding principal amount under the loan in exchange for 3,134,796 shares of our voting common stock.

On December 20, 2024, we terminated the K2HV Loan Agreement and repaid all remaining outstanding obligations.

Participation in our 2024 Public Offering

On April 24, 2024, we completed an underwritten public offering resulting in the issuance and sale of (a) 4,958,068 shares of Voting Common Stock, including the partial exercise of the underwriters’ option to purchase 2,485,487 additional shares of Voting Common Stock, at the closing market price on April 16, 2024, of $7.13 per share, and (b) Pre-Funded Warrants to purchase up to 18,577,419 shares of the Voting Common Stock, at a price of $7.1299 per warrant with an exercise price of $0.0001 per share.

We received aggregate net proceeds of approximately $161.4 million after deducting underwriting discounts, commissions and other

estimated offering expenses.

The following table summarizes purchases of the shares of our voting common stock and the pre-funded warrants by our related persons in connection with such underwritten public offering:

Shares of Common Stock

Shares of Common Stock Issuable Upon the Exercise of Pre-Funded Warrants

Total Purchase Price

Adage Capital Partners, L.P.

Baker Brothers Life Sciences, L.P.

Biotechnology Value Fund, L.P.

Biotechnology Value Fund II, L.P.

Biotechnology Value Trading Fund OS LP

MSI BVF SPV, LLC

Lynx1 Master Fund LP

In connection with the public offering, we agreed, among other things, to indemnify the underwriters in connection with the Securities Act of 1933, as amended.

The public offering was made pursuant to the shelf registration statement on Form S-3 (File No.

333-277699) that was filed with the SEC on March 6, 2024, and that was declared effective by the SEC on April 12, 2024, and a related prospectus supplement and its accompany base prospectus, filed with the SEC on April 18, 2024.

Participation in our 2024 Registered Direct Offering

On December 27, 2024, we completed a registered direct offering with an existing investor Lynx1 Master Fund LP (“Lynx1”) and an investment fund advised by Lynx1 resulting to in the sale and issuance of pre-funded warrants to purchase up to 7,500,000 shares of the Company's Voting Common Stock, at a purchase price of $4.00 per warrant with an exercise price of $0.0001 per share, for aggregate gross proceeds of approximately $30.0 million, before deducting offering expenses of $0.2 million.

Of these prefunded warrants, prefunded warrants to purchase up to 150,000 shares of Voting Common Stock for gross proceeds of $600,000 were sold to Lynx1 and prefunded warrants to purchase up to 7,350,000 shares of Voting Common Stock for gross proceeds of $29.4 million were sold to an investment fund advised by Lynx1.

The public offering was made pursuant to the shelf registration statement on Form S-3 (File No.

333-268260) that was filed with the SEC on November 9, 2022, and that was declared effective by the SEC on May 16, 2023, and a related prospectus supplement and its accompany base prospectus filed with the SEC on December 26, 2024.

Related person transaction policy

Our board of directors adopted a written related person transaction policy providing that transactions with our directors, officers and holders of five percent or more of our voting securities and their affiliates, each a related person, must be approved by our audit committee.

This policy became effective on July 15, 2021.

Pursuant to this policy, the audit committee has the primary responsibility for reviewing and approving or disapproving “related person transactions,” which are transactions between us and related persons in which the aggregate amount involved exceeds or may be expected to exceed the lesser of (i) $120,000 and (ii) one percent of the average of the Company’s total assets at year end for the last two completed fiscal years, and in which a related person has or will have a direct or indirect material interest.

For purposes of this policy, a related person is defined as a director, executive officer, nominee for director, or greater than five percent beneficial owner of our common stock, in each case since the beginning of the most recently completed year, and their immediate family members.

As appropriate for the circumstances, the audit committee will review and consider, among other things:

• the related person’s interest in the related person transaction;

• the approximate dollar amount involved in the related person transaction;

• the approximate dollar amount of the related person’s interest in the transaction without regard to the amount of any profit or loss;

• whether the transaction was undertaken in the ordinary course of our business;

• whether the terms of the transaction are no less favorable to us than terms that could have been reached with an unrelated third party;

• the business purpose for entering into a transaction with a related person versus an unrelated third party;

• any other material information regarding the transaction of the related person’s interest in the transaction.

Limitation of Liability and Indemnification of Officers and Directors

Our certificate of incorporation contains provisions that limit the liability of our directors for monetary damages to the fullest extent permitted by Delaware law.

Consequently, our directors will not be personally liable to us or our stockholders for monetary damages for any breach of fiduciary duties as directors, except liability for the following:

• any breach of their duty of loyalty to our company or our stockholders;

• any act or omission not in good faith or that involves intentional misconduct or a knowing violation of law;

• unlawful payments of dividends or unlawful stock repurchases or redemptions as provided in Section 174 of the Delaware General Corporation Law;

• any transaction from which they derived an improper personal benefit.

Any amendment to, or repeal of, these provisions will not eliminate or reduce the effect of these provisions in respect of any act, omission or claim that occurred or arose prior to that amendment or repeal.

If the Delaware General Corporation Law is amended to provide for further limitations on the personal liability of directors of corporations, then the personal liability of our directors will be further limited to the greatest extent permitted by the Delaware General Corporation Law.

In addition, our bylaws provide that we will indemnify, to the fullest extent permitted by law, any person who is or was a party or is threatened to be made a party to any action, suit or proceeding by reason of the fact that he or she is or was one of our directors or officers or is or was serving at our request as a director or officer of another corporation, partnership, joint venture, trust, or other enterprise.

Our bylaws provide that we may indemnify to the fullest extent permitted by law any person who is or was a party or is threatened to be made a party to any action, suit, or proceeding by reason of the fact that he or she is or was one of our employees or agents or is or was serving at our request as an employee or agent of another corporation, partnership, joint venture, trust or other enterprise.

Our bylaws also provide that we must advance expenses incurred by or on behalf of a director or officer in advance of the final disposition of any action or proceeding, subject to very limited exceptions.

We have entered into and in the future plan to enter into agreements to indemnify our directors and executive officers.

These agreements, among other things, require us to indemnify these individuals for certain expenses (including attorneys’ fees), judgments, fines and settlement amounts reasonably incurred by such person in any action or proceeding, including any action by or in our right, on account of any services undertaken by such person on behalf of our company or that person’s status as a member of our board of directors to the maximum extent allowed under Delaware law.

The information required by this Item 13 will be included in our definitive proxy statement to be filed with the SEC, with respect to our 2026 Annual Meeting of Stockholders and is incorporated by reference.

Principal Accountant Fees and Services.

TScan incurred the following fees from Deloitte for the audit of the consolidated financial statements and for other services provided during the years ended December 31, 2024 and 2023.

Fiscal Year 2024 ($)

Fiscal Year 2023 ($)

Audit Fees (1)

Audit-Related Fees

All Other Fees (3)

(1) Audit fees consist of fees for the audit of our annual financial statements, the review of our interim financial statements included in our quarterly reports on Form 10-Q and fees related to our follow-on offering, including comfort letters and consents.

(2) Tax fees consist of fees for tax compliance, advice and tax services.

There were no tax fees in fiscal years 2023 and 2024.

(3) All other fees disclosed in this table were related to the fees for access to technical accounting software resource provided by Deloitte.

Audit Committee Pre-Approval Policy and Procedures

Our audit committee has adopted policies and procedures relating to the approval of all audit and non-audit services that are to be performed by our independent registered public accounting firm.

This policy provides that we will not engage our independent registered public accounting firm to render audit or non-audit services unless the service is specifically approved in advance by our audit committee, or the engagement is entered into pursuant to the pre-approval procedure described below.

From time to time, our audit committee may pre-approve specified types of services that are expected to be provided to us by our independent registered public accounting firm during the next 12 months.

Any such pre-approval details the particular service or type of services to be provided and is also generally subject to a maximum dollar amount.

During our 2023 and 2024 fiscal years, no services were provided to us by Deloitte other than in accordance with the pre-approval policies and procedures described above.

The information required by this Item 14 will be included in our definitive proxy statement to be filed with the SEC, with respect to our 2026 Annual Meeting of Stockholders and is incorporated by reference.

Exhibits, Fin ancial Statement Schedules

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(incorporated by reference to Exhibit 3.2 to the Registrant’s Current Report on Form 8-K, filed with the Securities and Exchange Commission on July 20, 2021).

Fourth Amended and Restated Investors’ Rights Agreement, dated January 15, 2021, by and among the Registrant and the other parties thereto (incorporated by reference to Exhibit 4.2 to the Registrant’s Registration Statement on Form S-1 filed with the Securities and Exchange Commission on April 23, 2021).

Registration Rights Agreement made as of January 15, 2021 by and between the Registrant and the other parties thereto (incorporated by reference to Exhibit 4.3 to the Registrant’s Registration Statement on Form S-1 filed with the Securities and Exchange Commission on April 23, 2021).

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First Amendment to Lease by and between PPF OFF 828-830 Winter Street LLC and the Registrant, dated November 8, 2023 (incorporated by reference to Exhibit 10.1 to the Registrant’s Quarterly Report on Form 10-Q, filed with the Securities and Exchange Commission on November 9, 2023).

Second Amendment to Lease by and between PPF OFF 828-830 Winter Street LLC and the Registrant, dated October 28, 2024.

Second Amendment to Lease by and between PPF OFF 828-830 Winter Street LLC and the Registrant, dated October 28, 2024 (incorporated by reference to Exhibit 10.9 to the Registrant's Annual Report on Form 10-K, filed with the Securities and Exchange Commission on March 5, 2025).

Collaboration and License Agreement by and between the Registrant and Novartis Institutes for Biomedical Research, dated as of March 27, 2020 (incorporated by reference to Exhibit 10.8 to the Registrant’s Registration Statement on S-1 filed with the Securities and Exchange Commission on April 23, 2021).

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March 4, 2026

Chief Financial Officer (Principal Financial and Accounting Officer)

Chief Financial Officer (Principal Financial Officer)

Each person whose individual signature appears below hereby authorizes and appoints Gavin MacBeath and Jason A.

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March 4, 2026

(Principal Financial and Accounting Officer)

(Principal Financial Officer)

/s/ Leiden Dworak

Vice President, Finance

March 4, 2026

Leiden Dworak

(Principal Accounting Officer)

/s/ Garry Nicholson

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Stephen Biggar, M.D., Ph.D.

Katina Dorton

/s/ Katina Dorton

March 4, 2026

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Deferred revenue, current portion

Current portion of long-term debt

Total current liabilities

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Comprehensive loss:

Other comprehensive gain:

Unrealized gain on available-for-sale securities

Other comprehensive income (loss):

Unrealized gain (loss) on available-for-sale securities

Comprehensive loss

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Non-voting Common Stock

Comprehensive

Other Comprehensive

Stockholders’

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Exercise of stock options

Issuance of common stock, net of offering costs

Issuance of pre-funded warrants, net of offering costs

Conversion of non-voting common stock to voting common stock

Stock-based compensation expense

Balances at December 31, 2023

Exercise of stock options

Issuance of common stock under employee stock purchase plan

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Balances at December 31, 2024

Issuance of common stock under employee stock purchase plan

Issuance of common stock upon exercise of pre-funded warrants

Stock-based compensation expense

Unrealized loss on available-for-sale securities

Balances at December 31, 2025

The accompanying notes are an integral part of these consolidated financial statements

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Proceeds from maturities of marketable securities

Net cash used in investing activities

Net cash provided by (used in) investing activities

Cash flows from financing activities:

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Proceeds from exercise of stock options

Net cash provided by financing activities

Net increase in cash, cash equivalents and restricted cash

Cash paid for debt issuance costs

Cash paid for financing costs

Net cash provided by (used in) financing activities

Net increase (decrease) in cash, cash equivalents and restricted cash

Cash, cash equivalents, and restricted cash - beginning of year

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The Company expects to continue to generate operating losses in the foreseeable future.

The Company expects that its cash and cash equivalents and marketable securities as of December 31, 2024 will be sufficient to fund the Company’s operations for at least the next twelve months from the date of the issuance of the financial statements.

The Company expects that its cash and cash equivalents as of December 31, 2025 will be sufficient to fund the Company’s operations for at least the next twelve months from the date of the issuance of the financial statements.

The Company will need to obtain substantial additional funding through equity offerings, debt financings, collaborations, strategic alliances and/or licensing arrangements in order to fund its research and development and ongoing operating expenses.

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Recently Adopted Accounting Pronouncements

In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No.

2023-07, “Segment Reporting - Improvements to Reportable Segment Disclosures.” The ASU requires disclosure of incremental segment information on an annual and interim basis and also requires companies with a single reportable segment to provide all disclosures required by this ASU and all existing segment disclosures in Accounting Standard Codification (“ASC”) 280, “Segment Reporting.” The Company adopted this standard for this fiscal year ended December 31, 2024.

The adoption of ASU 2023-07 did not have a material impact on the Company’s consolidated financial statements and related disclosures.

Recently Issued Accounting Pronouncements Not Yet Effective

In December 2023, the FASB issued ASU No.

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This ASU is effective for annual periods beginning after December 15, 2024, and is applicable to the Company’s fiscal year beginning January 1, 2025, with early application permitted.

The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and disclosures.

The Company adopted this standard for the fiscal year ended December 31, 2025.

The adoption of ASU 2023-09 did not have a material impact on the Company's consolidated financial statements and related disclosures.

Recently Issued Accounting Pronouncements Not Yet Effective

In November 2024, the FASB issued Accounting Standards Update (ASU) 2024-04, Debt-Debt with Conversions and Other Options.

ASU 2024-04 is intended to clarify requirements for determining whether certain settlements of convertible debt instruments, including convertible debt instruments with cash conversion features or convertible debt instruments that are not currently convertible, should be accounted for as an induced conversion.

This ASU is effective for all entities for annual reporting periods beginning after

December 15, 2025, and interim reporting periods within those annual reporting periods, with early adoption permitted.

This ASU is effective for all entities for annual reporting periods beginning after December 15, 2025, and interim reporting periods within those annual reporting periods, with early adoption permitted.

The Company is currently evaluating the potential impact of this guidance on its disclosures.

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ASU 2024-03 is intended to improve disclosures about a public business entity’s expense and provide more detailed information to investors about the types of expenses in commonly presented expense captions.

The amendments in this ASU are effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027, with early adoption permitted.

The amendments in this ASU are effective for annual reporting periods beginning after December 15, 2026, and interim

reporting periods beginning after December 15, 2027, with early adoption permitted.

The Company is currently evaluating the potential impact of this guidance on its disclosures.

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Cash equivalents – money market funds

Marketable securities – government securities

Cash equivalents – government securities

Total financial assets

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Cash equivalents – money market funds

Cash equivalents – government securities

Marketable securities – government securities

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Assets and Liabilities Not Carried at Fair Value

The Company's convertible long-term debt was carried at amortized cost.

The fair value of the convertible long-term debt was estimated to be $ 38.4 million at December 31, 2023.

Fair value was determined using a convertible bond model using a binomial lattice approach.

We classified the fair value disclosures for the long-term debt within level 3 of the fair value hierarchy because the fair value is derived using significant unobservable inputs, which include discount rates and volatility.

The Company's convertible long-term debt was extinguished on December 20, 2024.

The carrying value of accounts payable and accrued expenses that are reported on the consolidated balance sheets approximate fair value due to the short-term nature of these liabilities.

Based on the borrowing rates currently available to the Company for bank loans with similar maturities, the fair value of long-term debt is approximately equal to its carrying amount as of December 31, 2024.

Accrued Expenses and Other Current Liabilities

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Equity Offerings

On June 1, 2023, the Company completed an underwritten public offering resulting in the issuance and sale of (a) 23,287,134 shares of Voting Common Stock, at a price of $ 2.00 per share, and (b) pre-funded warrants (Pre-Funded Warrants) to purchase up to 47,010,526 shares of the Voting Common Stock, at a price of $ 1.9999 per warrant with an exercise price of $ 0.0001 per share.

On June 1, 2023, the Company completed an underwritten public offering resulting in the issuance and sale of (a) 23,287,134 shares of Voting Common Stock, at a price of $ 2.00 per share, and (b) pre-funded warrants (Pre-Funded Warrants) to purchase up to 47,010,526 shares of the Voting Common Stock, with a purchase price of $ 1.9999 per warrant and an exercise price of $ 0.0001 per warrant.

The Company received aggregate net proceeds of $ 134.7 million after deducting underwriting discounts, commissions and other offering expenses, with $ 42.4 million allocated to the Voting Common Stock and $ 92.3 million allocated to Pre-Funded Warrants.

On April 24, 2024, the Company completed an underwritten public offering resulting in the issuance and sale of (a) 4,958,068 shares of Voting Common Stock, including the partial exercise of the underwriters’ option to purchase 2,485,487 additional shares of Voting Common Stock, at the closing market price on April 16, 2024, of $ 7.13 per share, and (b) Pre-Funded Warrants to purchase up to 18,577,419 shares of the Voting Common Stock, at a price of $ 7.1299 per warrant with an exercise price of $ 0.0001 per share.

On April 24, 2024, the Company completed an underwritten public offering resulting in the issuance and sale of (a) 4,958,068 shares of Voting Common Stock, including the partial exercise of the underwriters’ option to purchase 2,485,487 additional shares of Voting Common Stock, at the closing market price on April 16, 2024, of $ 7.13 per share, and (b) Pre-Funded Warrants to purchase up to 18,577,419 shares of the Voting Common Stock, with a purchase price of $ 7.1299 per warrant and an exercise price of $ 0.0001 per warrant.

The Company received aggregate net proceeds of approximately $ 161.4 million after deducting underwriting discounts, commissions and other offering expenses, with $ 33.1 million allocated to the Voting Common Stock and $ 128.3 million allocated to Pre-Funded Warrants.

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The Pre-Funded Warrants were determined to be equity classified because they are freestanding financial instruments that are legally detachable and separately exercisable from the equity instruments, are immediately exercisable, do not embody an obligation for the Company to repurchase its shares, permit the holders to receive a fixed number of common shares upon exercise, are indexed to the Company’s common stock and meet the equity classification criteria.

addition, the Pre-Funded Warrants do not provide any guarantee of value or return.

As such, proceeds received from the issuance from the Pre-Funded Warrants were recorded as a component of stockholders’ equity within additional paid-in capital.

As of December 31, 2024, no Pre-Funded Warrants have been exercised.

In addition, the Pre-Funded Warrants do not provide any guarantee of value or return.

As such, proceeds received from the issuance of the Pre-Funded Warrants were recorded as a component of stockholders’ equity within additional paid-in capital.

During the year ended December 31, 2025 , the Company issued an aggregate of 76,170 shares of its common stock pursuant to the cashless exercise of 76,178 Pre-Funded Warrants at a weighted average exercise price of $ 0.0001 per share.

The Company did no t issue any common stock pursuant to the exercise of Pre-Funded Warrants during the year ended December 31, 2024.

Common Stock Reserved for Future Issuance

The Company has reserved the following shares of common stock for future issuance:

Stock options outstanding

Pre-Funded Warrants outstanding

Shares available for future grant under 2021 Plan

Shares available for future issuance under 2021 ESPP

Total shares of common stock reserved

Stock-Based Compensation

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The Company lacks sufficient company-specific historical and implied volatility information.

Therefore, it estimates its expected stock volatility based on the historical volatility of a publicly traded set of peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price.

regarding the volatility of its own traded stock price.

For options with service-based vesting conditions, the expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options.

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During the years ended December 31, 2025 and 2024, the Company did not record an income tax provision due to the losses incurred and a full valuation allowance provided on the net deferred tax assets.

A reconciliation of the federal statutory income tax rate to the effective tax rate is as follows :

Year Ended December 31,

In December 2023, the FASB issued ASU 2023-09, "Income Taxes (Topic 740):

Improvements to Income Tax Disclosures,” effective for annual periods beginning after December 15, 2024.

ASU 2023-09 requires companies to present a detailed reconciliation of the statutory and effective income tax rates, including specified categories such as state and local taxes, foreign taxes, tax credits, and changes in valuation allowances, to provide greater transparency into the factors affecting the effective tax rate.

The standard also mandates disclosure of income taxes paid, disaggregated by federal, state, and foreign jurisdictions, enabling users to better understand the company’s cash tax payments across different tax authorities.

Furthermore, companies must describe significant tax positions and valuation allowances, including the nature and amounts of such positions, and the judgments or assumptions underlying their recognition or measurement.

ASU 2023-09 permits companies to apply these enhanced disclosure requirements either retrospectively to all periods presented or prospectively to periods beginning after the adoption date;

the Company has elected to adopt the standard prospectively.

The adoption of ASU 2023-09 had no impact to the Company’s consolidated balance sheets, consolidated statements of comprehensive (loss) income, or consolidated statements of cash flows, as ASU 2023-09 affects disclosures only.

On July 4, 2025, the One Big Beautiful Bill Act (the "OBBBA") was enacted, providing taxpayers the option to fully deduct or continue capitalizing and amortizing domestic R&D expenditures under new Code Section 174A, effective for tax years beginning after December 31, 2024.

The OBBBA also provides certain eligible taxpayers with the option to accelerate and deduct the remaining unamortized domestic R&D costs incurred during taxable years ending after December 31, 2021 and before January 1, 2025.

The Company intends to continue amortizing domestic R&D costs incurred during taxable years ending after December 31, 2021 and before

January 1, 2025.

As of December 31, 2025, $ 129.3 million remains unamortized related to domestic R&D costs.

Final elections will be made with the 2025 tax return filing.

A reconciliation of the federal statutory income tax rate to the effective rate for the year ended December 31, 2024 is as follows:

Taxes at U.S.

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Effective income tax rate

A reconciliation of the federal statutory income tax rate to the effective rate for the year ended December 31, 2025 is as follows (in thousands, except percentages):

Federal Statutory Income Tax (Benefit) at 21 %

Domestic Federal

Non Taxable or Non Deductible

Excess Officer Compensation

Stock Compensation

Change in valuation allowance

Deferred tax assets and liabilities reflect the net tax effects of net operating loss carryovers and temporary differences between the carrying amount of assets and liabilities for financial reporting and the amounts used for income tax purposes.

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The Company is subject to taxation for federal and Massachusetts purposes.

As of December 31, 2024 , the Company is subject to examination by these taxing authorities for all years since inception.

As of December 31, 2025 , the Company is subject to examination by these taxing authorities for all years since inception in 2018.

Collaboration and License Agreements

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The Company will recognize the revenue associated with the performance obligation using an input method.

The method of measuring progress towards delivery of the services incorporates actual internal and external costs incurred, relative to total internal and external costs expected to be incurred to satisfy the performance obligation.

The method of measuring progress towards delivery of

the services incorporates actual internal and external costs incurred, relative to total internal and external costs expected to be incurred to satisfy the performance obligation.

Changes in estimates of total internal and external costs expected to be incurred are recognized in the period of change as a cumulative catch-up adjustment.

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The Company will continue to assess the probability of the option to add additional targets and the probability of milestone achievement throughout the research term and will adjust the consideration in the contract accordingly.

For the year ended December 31, 2024 and 2023 the Company recognized $ 2.8 million and $ 14.2 million, respectively, of revenue associated with the Amgen Agreement.

As of December 31, 2024, the Company recorded $ 12.9 million of deferred revenue, of which $ 1.2 million is classified as long-term.

In March 2020 , the Company entered into a Collaboration and License Agreement (the Novartis Agreement) with Novartis Institutes For BioMedical Research, Inc.

(Novartis) to collaborate on their research efforts to discover and develop novel TCR-T therapies.

At the inception date of the Novartis Agreement, Novartis or its affiliates held an ownership interest of more than 10 % in the Company, and at December 31, 2024 and 2023, Novartis held less than 10 % of the common shares outstanding.

Under the Novartis Agreement, the Company was to identify and characterize TCRs in accordance with a research plan, and transfer data arising from the research plan.

The Novartis Agreement provided for payments of an upfront fee of $ 20.0 million, research funding totaling $ 10.0 million, and potential milestone payments contingent on clinical, regulatory and sales success.

The Company concluded that the performance of the research services was the predominant performance obligation and was recognizing the revenue associated with the performance obligation using the input method, according to the actual costs incurred as a percentage of total expected costs to complete the research services.

The Company determined that the $ 20.0 million upfront payment, together with the $ 10.0 million of estimated research costs to be reimbursed by Novartis to be the entirety of the consideration to be included in the transaction price as of the outset of the arrangement.

The potential milestone payments that the Company is eligible to receive were excluded from the transaction price, as all milestone amounts were fully constrained based on the assessed probability of achievement.

During the year ended December 31, 202 3 the Company recognized $ 5.8 million of revenue associated with the Novartis Agreement, of which $ 1.9 million r elated to cost reimbursements under the Novartis Agreement that offset costs incurred within research and development expenses in the statements of operations.

The research term ended in March 2023.

For the years ended December 31, 2025 and 2024, the Company recognized $ 10.3 million and $ 2.8 million, respectively, of revenue associated with the Amgen Agreement.

As of December 31, 2025, the Company recorded $ 2.6 million of deferred revenue which is classified as short-term.

Commitments and Contingencies

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Given uncertainty as to the Company's intentions with respect to these leases, the renewal options were not deemed reasonably certain.

On November 8, 2023, the Company entered into a lease amendment extending the expiration date of the 830 Winter Street Lease from September 30, 2024 to October 31, 2029 and provides for one option to renew the 830 Winter Street Lease for a five-year period commencing on November 1, 2029 , resulting in an increase in the lease liability of $ 6.2 million.

On October 28, 2024, the Company entered into a second lease amendment expanding the rentable space of 830 Winter Street.

The amendment provides for an additional 25,628 square feet of space with a commencement date of December 1, 2024 and an expiration date of October 31, 2029 with one option to review for a five-year period.

The amendment provides for an additional 25,628 square feet of space with a commencement date of December 1, 2024 and an expiration date of October 31, 2029 with one option to renew for a five-year period.

This amendment resulted in an increase in the lease liability of $ 6.1 million.

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Operating lease costs

Short-term lease costs

Variable lease costs

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The Company recognized a loss from extinguishment of $ 1.1 million.

The Company recorded $ 3.6 million and $ 3.8 million in interest expense for the years ended December 31, 2024 and 2023 , respectively.

The Company recorded $ 3.6 million in interest expense for the year ended December 31, 2024 .

The effective interest rate on the Loan Agreement, including the amortization of the debt discount and issuance costs, and accretion of the Exit Fee, was 12.61 % upon extinguishment.

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The SVB Loan Agreement contains customary representations and warranties, events of default and affirmative and negative covenants, including covenants that limit or restrict the Company’s and its subsidiaries’ ability to, among other things, dispose of assets, make changes to its business, management, ownership or business locations, merge or consolidate, incur additional indebtedness, grant liens on its assets, pay dividends or other distributions, repurchase equity, make investments, and enter into certain transactions with affiliates, in each case subject to certain thresholds and exceptions.

The New Loan Agreement does not require the Company to comply with a financial maintenance covenant.

As collateral for its obligations under the New Loan Agreement, the Company granted the Lender a first-priority security interest on substantially all of the Company’s assets (other than intellectual property), subject to certain exceptions.

The SVB Loan Agreement does not require the Company to comply with a financial maintenance covenant.

As collateral for its obligations under the SVB Loan Agreement, the Company granted the Lender a first-priority security interest on substantially all of the Company’s assets (other than intellectual property), subject to certain exceptions.

The Company’s obligations under the SVB Loan Agreement will be guaranteed by each of the Company’s future direct or indirect subsidiaries, subject to certain exceptions.

The Company recorded $ 0.1 million in interest expense for the year ended December 31, 2024.

The Company recorded $ 2.8 million and $ 0.1 million in interest expense for the years ended December 31, 2025 and 2024 , respectively.

The effective interest rate on the SVB Loan Agreement, including the amortization of the debt discount and issuance costs, and accretion of the Exit Fee, was 8.46 % at December 31, 2025.

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The Company made contributions to the Plan of $ 1.3 million and $ 1.0 million for the years ended December 31, 2025 and 2024 , respectively.

Restructuring

On November 3, 2025, following the Company's alignment with the U.S.

Food and Drug Administration (FDA) on the registrational path forward for the TSC-101 program, the Company made the strategic decision to prioritize clinical development of its heme program and pause further enrollment in its solid tumor Phase 1 trial, while focusing its preclinical efforts on in vivo engineering for solid tumors and target discovery in autoimmunity.

Pursuant to this strategy, the Company also implemented a workforce reduction of approximately 30 %, or 66 roles.

As part of this strategic restructuring, the Company incurred expenses of approximately $ 2.0 million for severance-related benefits and other costs, of which $ 1.6 million is included in research and development expenses and $ 0.4 million is included in general and administrative expenses in the accompanying consolidated statements of operations.

Approximately $ 1.0 million of accrued severance-related benefits and other costs are included in accrued expenses on the consolidated balance sheet as of December 31, 2025.

These payments are expected to be completed in the fourth quarter of 2026.

The following table summarizes the Company's liability recognized in connection with the restructuring (in thousands):

Balance as of January 1, 2025

Severance-related benefits and other costs

Cash payments

Balance as of December 31, 2025

Segment Reporting

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Research and development:

Personnel expenses

Laboratory supplies, research materials and studies

Clinical studies

Personnel expenses

Facility-related and other

Clinical studies

Stock-based compensation

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Depreciation expense

Loss from operations

Other (expense) income:

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Potential shares issuable under the ESPP

Common stock issuable upon conversion of Loan Agreement

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 9A. Controls and Procedures