TScan Therapeutics Gets FDA RMAT Designation for Two Lead TCR-T Therapies for Heme Malignancies

TScan Therapeutics, Inc., a clinical-stage biopharmaceutical company, recently announced that the U.S. Food and Drug Administration (FDA) has granted Regenerative Medicine Advanced Therapy (RMAT) designation to its two leading T cell receptor (TCR)-engineered T cell (TCR-T) therapy candidates: TSC-100 and TSC-101. These candidates are designed for the treatment of patients with acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), and myelodysplastic syndrome (MDS) who are undergoing allogeneic hematopoietic cell transplantation (HCT) with reduced intensity conditioning.

Dr. Chrystal U. Louis, Chief Medical Officer at TScan, expressed enthusiasm about the RMAT designation, citing it as a significant milestone that acknowledges the transformative potential of TSC-100 and TSC-101 in treating challenging cancers. She emphasized the company's commitment to working closely with the FDA to bring life-changing therapies to patients.

The RMAT designation, established under the 21st Century Cures Act, aims to expedite the development and review of promising regenerative medicines, including gene and cell therapies. To qualify for this designation, a therapy must aim to treat, modify, reverse, or cure a serious or life-threatening condition, with preliminary clinical evidence showing its potential to address unmet medical needs. RMAT designation offers benefits such as intensive FDA guidance, early interactions with the FDA on development processes, potential priority review, and opportunities for accelerated approval.

TScan’s TSC-100 and TSC-101 target minor histocompatibility antigens HA-1 and HA-2, respectively. The company is selecting HLA A*02:01-positive transplant patients who are either HA-1 or HA-2 positive, with donors who are negative for these antigens. TSC-100 and TSC-101 are designed to eliminate all recipient hematopoietic cells, including malignant, pre-malignant, or normal cells, that persist post-transplant while leaving donor-derived cells unaffected. This approach aims to reduce the relapse rate in patients undergoing allogeneic HCT with reduced intensity conditioning, as approximately 40% of such patients relapse within two years of transplant, facing limited treatment options and poor prognosis.

On May 13, 2024, TScan provided an update on its Phase 1 heme malignancies program. The update revealed that, with a median follow-up of over 10 months, all eight patients treated with TSC-100 or TSC-101 remained relapse-free with no detectable disease and no dose-limiting toxicities observed. In comparison, two of the eight control-arm patients relapsed approximately six months post-transplant, with one patient dying three months later. Another control-arm patient required clinical intervention due to concerns of impending relapse, and a fourth control-arm patient died post-transplant.

TScan Therapeutics, Inc., is dedicated to developing TCR-T therapies for the treatment of cancer. The company’s lead candidates, TSC-100 and TSC-101, focus on preventing relapse in patients with hematologic malignancies following allogeneic HCT. TScan is also working on TCR-T candidates for various solid tumors and expanding its ImmunoBank, a repository of therapeutic TCRs recognizing diverse targets associated with multiple HLA types. This bank aims to provide customized multiplex therapeutic TCR-Ts for a variety of cancer patients.

The company acknowledges the inherent risks and uncertainties involved in drug development but remains committed to advancing its therapies and achieving its goal of providing effective cancer treatments.