TScan Therapeutics Announces 2023 Clinical Plans and Highlights Recent Progress

Phase 1 umbrella trial of TSC-100 and TSC-101 active in five sites; on track to enroll first two cohorts in 1H 2023 with interim data by end of 2023

Advancing solid tumor program with development of several TCRs for multiple HLAs across multiple targets; INDs filed for two MAGE-A1 TCRs (TSC-204-A0201 and TSC-204-C0702) as well as IND for multiplexing TCRs

Cash runway funds operations into 2Q 2024

WALTHAM, Mass., Jan. 05, 2023 (GLOBE NEWSWIRE) — TScan Therapeutics, Inc. (Nasdaq: TCRX), 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, today announced its 2023 clinical pipeline plans and highlighted recent corporate achievements.

“We made significant progress and growth in 2022, positioning both our solid tumor and hematologic malignancies programs for important data readouts in 2023,” said David P. Southwell, President and Chief Executive Officer. “Our solid cash runway funds us well into 2024, seeing us through to multiple value-generating milestones. We believe that 2023 will be a pivotal year for TScan as we continue to advance our industry-leading clinical stage portfolio of TCR-T therapy candidates in both our solid tumor and hematologic malignancies programs.”

Debora Barton, M.D., Chief Medical Officer added, “We look forward to multiple clinical milestones next year. Specifically, we expect an interim data read out from our Phase 1 umbrella trial in prevention of relapse post-transplant for hematological malignancies as well as preliminary data for our most advanced solid tumor TCRs by the end of 2023.”

2022 Key Achievements and Recent Company Highlights

Hematologic Malignancies Program:

• FDA clearance of IND applications for TSC-100 and TSC-101 for the prevention of relapse following hematopoietic cell transplant (HCT) in acute myeloid leukemia (AML), myelodysplastic syndromes (MDS), and acute lymphocytic leukemia (ALL)
• Initiated multi-arm clinical trial with five clinical sites activated, with additional sites to be added in 2023
• Presented Phase 1 umbrella trial in progress poster on HA-1 (TSC-100) and HA-2 (TSC-101) at the 64^th American Society of Hematology (ASH) annual meeting 2022
  • Phase 1 trial design and translational assays designed to show early evidence of biological activity in residual leukemia after HCT
• Developed translational research program for early evaluation of efficacy
  • Novel high-sensitivity next-generation sequencing assays to measure minimal residual disease and donor chimerism

Solid Tumor Programs

• FDA support for multiplexing clinical development plan through “T-plex” IND allowing simultaneous administration of multiple TCRs following singleplex dose escalation
• Filed initial three INDs for solid tumor program (T-plex, TSC-204-A0201, TSC-204-C0702) with four additional IND filings expected in 2023
• Built in-house in vivo pharmacology and in vitro toxicology capabilities to support rapid filing of additional TCR INDs to further expand the ImmunoBank
• Developed clinical trial assays to enable prospective patient selection through analysis of target and HLA status of tumor samples
• Presented preclinical data for solid tumor program at the 37^th Society for Immunotherapy of Cancer (SITC) annual meeting 2022:
  • TCR for an HLA-A*02:01 epitope of PRAME
  • Multiplexing TCRs for MAGE-A1 and PRAME demonstrated synergistic cytotoxicity in vitro and in mouse xenograft models
• Presented preclinical data at the American Society of Gene and Cell Therapy (ASGCT) 25^th annual meeting 2022
  • Identified lead TCR-T cell therapy candidate, TCR-200-A0201, for the treatment of HPV-positive solid tumors
• Publication in Cell highlights the discovery of novel tumor antigens and high affinity TCRs for the treatment of solid tumors using TScan’s foundational screening technology
  • TScan screening technology identified targets of expanded T cell clones in the tumors of patients with head and neck cancer responding to neoadjuvant immunotherapy, an indication for which the Company is developing potential new therapies
• Hosted virtual KOL events on solid tumor program and highlights from ASGCT and SITC annual meetings

Corporate

• Appointed Debora Barton, M.D. as Chief Medical Officer and Leiden Dworak, CPA, MBA, as Vice President, Finance
• Named highest-placed midsize biotechonology company in Top Places to Work for 2022 by The Boston Globe

Clinical Plans and Expected Milestones

• In the hematologic malignancies program, the Company expects to enroll the first two cohorts in the Phase 1 umbrella trial (NCT05473910) for TSC-100 and TSC-101 in the first half of 2023 and to report top-line data by the end of 2023. Additionally, the Company expects to share prevention of relapse data in 2024
• In the solid tumor program, the Company plans to file INDs for HPV (TSC-200-A0201) and PRAME (TSC-203-A0201) in the first half of 2023 with two additional INDs to be filed by the end of 2023; expects preliminary clinical data for the most advanced TCRs by the end of 2023. The Company expects to report initial multiplex therapy data for this program in 2024

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, in order 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 Phase 1 umbrella trial for TSC-100 and TSC-101, including enrollment, and the presentation of data, the Company’s plans, progress, and timing relating to the submission of INDs for the Company’s solid tumor programs and T-Plex and the presentation of data, the Company’s ability to fund its operating expenses and capital expenditure requirements with its existing cash and cash equivalents, 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 or current or future product candidates in treating patients, and the Company’s goals, strategy, and financial performance. 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