TSC-101 is an HA-2-specific TCR-T therapy candidate directed at eliminating white blood cells, including residual cancer cells, in HLA-A*02:01-positive patients undergoing standard-of-care HCT. HA-2 is a minor histocompatibility antigen that is present on all blood cells, malignant or benign. We believe that healthy donor T cells engineered to express an HA-2-specific TCR will generate an anti-cancer effect in patients, leading to a reduction in relapse rates post-HCT and an increase in long-term survival.

We are currently conducting a Phase 1 clinical study of TSC-101 in patients with AML, ALL or MDS undergoing a standard-of-care HCT. Eligible patients require transplant donors who do not have the HLA-A*02:01 allele. For more detailed information about our ongoing clinical study please visit: NCT05473910.

We designed our heme program around the clinical observation that patients who naturally develop T cells against HA-2 have lower relapse rates. We are focusing on patients that are HLA-A*02:01-positive (and therefore HA-2-positive) who have donors that are HLA-A*02-negative. While the patient is undergoing HCT, the donor’s T cells are engineered with a TCR that recognizes HA-2. Following the transplant, we infuse the patient with the engineered donor-derived T cells, at which point those T cells will target any residual cancer cells because they are patient-derived and therefore HA-2-positive, but won’t touch any of the new blood cells because they are derived from the donor and are therefore HA-2-negative.

Expansion Opportunities

We plan to further expand this program with the addition of TCRs targeting additional HLA types. CD45 is a protein exclusively expressed on hematopoietic cells. Like TSC-101, TSC-102-A0301 is an allogeneic, donor derived TCR-T therapy product candidate targeting CD45 and has been designed to eliminate residual cancer cells in patients who are HLA-A*03:01-positive undergoing HCT using a donor who is HLA-A*03:01-negative.