TScan Announces Targets for Two Planned INDs in 2021 to Treat Liquid Tumors

• TScan Advances Lead TCR for HA-1, TSC-100, to IND-enabling Activities
• TScan Names HA-2 as Second Target, Expanding Pool of Addressable Patients

On Track for Solid Tumor Target Nominations in 2021

WALTHAM, Mass.--(BUSINESS WIRE)-- TScan Therapeutics, a biopharmaceutical company focused on the development of T cell receptor (TCR)-engineered T cell therapies in oncology, today announced plans to file two Investigational New Drug (IND) applications in their liquid tumor program in 2021. Their first product, TSC-100, targets HA-1 and is designed to treat patients receiving hematopoietic stem cell transplant therapy with the goal of preventing relapse, a high unmet need in this setting. TScan announced selection of their lead TCR and its advancement to IND-enabling activities. Simultaneously, TScan announced selection of their second target, HA-2, with plans to file a second IND in 2021. These products are the first two TCRs in a multi-TCR program designed to provide treatment options for the majority of patients receiving stem cell therapy.

“We are excited to progress this T cell therapy solution for patients receiving stem cell transplant therapy,” said David Southwell, Chief Executive Officer at TScan. “TScan’s goal in both its liquid and solid tumor programs is to learn from patients who respond well to therapy to treat those who are less fortunate. This represents a significant step in the progression of TScan as a TCR therapy company. Our lead TCR, TSC-100, was discovered internally using our TCR discovery platform, R-Scan, and was significantly derisked using our proprietary genome-wide safety screening platform, T-Scan. By extending our liquid tumor program to also include HA-2, we are one step closer to providing a comprehensive solution for patients receiving stem cell therapy. We also remain on track to nominate solid tumor targets in 2021.”

Leveraging its core TCR discovery platform, R-Scan, TScan identified its lead HA-1 TCR after screening over 100,000,000 T cells from HA-1-negative donors. In preclinical experiments, TSC-100 showed strong activity against HA-1-positive leukemia cells and a clean safety profile, with minimal off-target interactions or alloreactivity. TSC-100 will be used to engineer donor T cells in the context of a stem cell transplant, with the goal of preventing relapse in HA-1-positive patients with AML, MDS, or adult ALL. To expand this program to patients not expressing HA-1, TScan is developing a second TCR specific for HA-2, termed TSC-101.

“Our goal is to provide a therapeutic option for every patient,” said Gavin MacBeath, Chief Scientific Officer. “Our discovery team is already identifying TCRs that will allow our products to address an even broader patient population. Expanding our repository of therapeutic TCRs also enables us to develop multiplexed TCR therapies, which better mimic natural immune responses and provide more robust treatments for heterogeneous cancers like AML, as well as a diverse range of solid tumors. Using our two core platforms, we remain on track to nominate our first solid tumor candidates in early 2021.”

About HA-1

HA-1 is a well-characterized minor histocompatibility antigen that is expressed on all blood cells, including leukemia cells, but is not expressed at appreciable levels in other normal tissues. It is associated with clinical benefit by generating a ‘graft vs. leukemia’ effect in the context of hematopoietic stem cell transplants in which the patient is HA-1-positive and the donor is HA-1-negative. Over half of all patients express the HA-1 target.

About HA-2

Similar to HA-1, HA-2 is a minor histocompatibility antigen expressed specifically on blood cells and is associated with clinical benefit through a ‘graft vs. leukemia’ effect. Addition of TSC-101, an HA-2-specific TCR, will expand the pool of eligible patients for TScan’s liquid tumor program.

About TScan Therapeutics

TScan discovers and develops transformative T cell therapies (TCR-T) to treat liquid cancers, solid tumors, and other serious diseases. Our proprietary, high-throughput platform identifies previously uncharacterized, clinically-derived shared T cell antigens and all off-target TCR interactions, to enable the development of highly efficacious TCR-Ts with minimal off-target effects. Lead program TSC-100 is expected to enter clinical development for liquid cancers in 2021, and the Company is advancing additional TCR-Ts for solid cancers. TScan was co-founded by Chair Christoph Westphal (Partner, Longwood Fund) based on pioneering research from the Elledge Lab at Brigham and Women’s Hospital. The Company has raised over $80 million to date from leading strategic collaborators and investors including Longwood Fund, Novartis Institutes for Biomedical Research, Astellas Venture Management, Novartis Venture Fund, Bessemer Venture Partners, GV, 6 Dimensions Capital, and Pitango Venture Capital.

For more information, please visit www.tscan.com

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