TScan Therapeutics (TCRX) 8-K TScan Therapeutics Announces Transition of Chief Financial Officer

Exhibit 99.1

TScan Therapeutics Announces Transition of Chief Financial Officer

WALTHAM, Mass., June 29, 2023 — TScan Therapeutics, Inc. (Nasdaq: TCRX), a clinical-stage biopharmaceutical company focused on the development of T cell receptor (TCR)-engineered T cell therapies (TCR-Ts) for the treatment of patients with cancer, today announced that its Chief Financial Officer, Brian M. Silver, J.D., will be leaving the Company, effective July 21, 2023, to pursue a new opportunity at a leading advisory firm based in New York, where he lives with his family. Brian will continue to be available to provide strategic advice for the Company. The Company has initiated a search for a successor chief financial officer.

“We extend our sincere thanks to Brian for his important contributions since joining the Company and wish him well in his new endeavor,” said Gavin MacBeath, Ph.D., Chief Executive Officer. “Brian’s extensive experience in biotechnology executive leadership roles has been crucial in ensuring the financial strength of the Company and has allowed him to contribute to the advancement of our strategy and clinical programs. We are pleased that Brian will be able to continue his relationship with TScan by providing strategic advice, as his expertise, knowledge, vision, energy, and passion have proven invaluable to our Company.”

“It has been a privilege working initially as a board member and then as an executive with my colleagues at TScan. I am proud to have helped TScan grow from a preclinical platform company to a fully integrated research, development and manufacturing organization working to improve the lives of patients with cancer and autoimmune disease through the development of advanced cell therapies. I look forward to continuing to provide strategic input to TScan in the future,” said Mr. Silver. “With the proceeds of our convertible note with K2, the Amgen research partnership and our follow-on financing, I am confident that TScan has the financial capability to execute on our significant clinical milestones into 2026.”

About TScan Therapeutics, Inc.

TScan is a clinical-stage biopharmaceutical company focused on the development of T cell receptor (TCR)-engineered T cell therapies (TCR-T) for the treatment of patients with cancer. The Company’s lead TCR-T therapy candidates, TSC-100 and TSC-101, are in development for the treatment of patients with hematologic malignancies to eliminate residual disease and prevent relapse after allogeneic hematopoietic cell transplantation. The Company is also developing multiplexed TCR-T therapy candidates for the treatment of various solid tumors. The Company has developed and continues to build its ImmunoBank, the Company’s repository of therapeutic TCRs that recognize diverse targets and are associated with multiple HLA types, to provide customized multiplexed TCR-T therapies for patients with a variety of solid tumors.

Forward-Looking Statements

This release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including, but not limited to, express or implied statements regarding the Company’s plans, progress, and timing relating to the Company’s solid tumor programs and the presentation of data, the Company’s current and future research and development plans or expectations, the structure, timing and success of the Company’s planned preclinical development, submission of INDs, and clinical trials, the potential benefits of any of the

Company’s proprietary platforms, multiplexing, or current or future product candidates in treating patients, and the Company’s goals and strategy. TScan intends such forward-looking statements to be covered by the safe harbor provisions for forward-looking statements contained in Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995. In some cases, you can identify forward-looking statements by terms such as, but not limited to, “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “anticipate,” “project,” “target,” “design,” “estimate,” “predict,” “potential,” “plan,” “on track,” or similar expressions or the negative of those terms. Such forward-looking statements are based upon current expectations that involve risks, changes in circumstances, assumptions, and uncertainties. The express or implied forward-looking statements included in this release are only predictions and are subject to a number of risks, uncertainties and assumptions, including, without limitation: the beneficial characteristics, safety, efficacy, therapeutic effects and potential advantages of TScan’s TCR-T therapy candidates; TScan’s expectations regarding its preclinical studies being predictive of clinical trial results; the timing of the initiation, progress and expected results of TScan’s preclinical studies, clinical trials and its research and development programs; TScan’s plans relating to developing and commercializing its TCR-T therapy candidates, if approved, including sales strategy; estimates of the size of the addressable market for TScan’s TCR-T therapy candidates; TScan’s manufacturing capabilities and the scalable nature of its manufacturing process; TScan’s estimates regarding expenses, future milestone payments and revenue, capital requirements and needs for additional financing; TScan’s expectations regarding competition; TScan’s anticipated growth strategies; TScan’s ability to attract or retain key personnel; TScan’s ability to establish and maintain development partnerships and collaborations; TScan’s expectations regarding federal, state and foreign regulatory requirements; TScan’s ability to obtain and maintain intellectual property protection for its proprietary platform technology and our product candidates; the sufficiency of TScan’s existing capital resources to fund its future operating expenses and capital expenditure requirements; and the effect of the COVID-19 pandemic, including mitigation efforts and political, economic, legal and social effects, on any of the foregoing or other aspects of TScan’s business or operations; and other factors that are described in the “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” sections of TScan’s most recent Annual Report on Form 10-K and any other filings that TScan has made or may make with the SEC in the future. Any forward-looking statements contained in this release represent TScan’s views only as of the date hereof and should not be relied upon as representing its views as of any subsequent date. Except as required by law, TScan explicitly disclaims any obligation to update any forward-looking statements.

Contacts

Heather Savelle

TScan Therapeutics, Inc.

VP, Investor Relations

857-399-9840

hsavelle@tscan.com

Joyce Allaire

LifeSci Advisors, LLC

Managing Director

617-435-6602

jallaire@lifesciadvisors.com