Oncology
T cells are a crucial component of the immune system and play a central role in the body’s defense against infections, cancer, and other diseases.
T cell receptors (TCRs) are located on the surface of T cells and recognize foreign antigens. Cancer-specific TCRs recognize antigens on the surface of cancer cells, but not normal cells, triggering the T cells to become activated and kill the cancer cell while sparing normal cells.
To make a TCR-T product, T cells are genetically engineered to express a TCR that recognizes an antigen on cancer cells. When those TCR-T cells are infused into a patient, they act as a living drug, targeting and eliminating their cancer cells.
Solid Tumors
We are focused on developing in vivo-engineered TCR-T cell therapy product candidates for the treatment of solid tumor indications. We believe our in vivo engineering approach will overcome the key limitations of ex vivo-engineered autologous TCR-T, including the cost and difficulty of patient-specific manufacturing, the delay in getting product to patients, and the need for lymphodepletion. Our plan is to build upon the success and learnings from our ex-vivo-manufactured TCR-T program (the Phase 1 PLEXI-T™ study). We have identified our first two therapeutic candidates, one targeting PRAME and the other targeting MAGE-A4.
TScan’s third generation lentiviral vector enables in vivo generation of TCR-T cells. Our construct consists of two proprietary components: dual targeting antibodies that direct the virus to cytotoxic and helper T-cells and mediate T cell activation, and a non-targeting fusogen that mediates entry exclusively to T-cells.
One of the challenges of treating solid tumors is that they are heterogeneous – not every tumor cell expresses a given target. Our strategy is to advance development of our in vivo-engineered TCR-T therapy candidates initially as singleplexed therapy. Ultimately we hope to address the heterogeneity of solid tumors and plan to develop what we refer to as multiplex TCR-T therapy, in which we treat a patient with more than one TCR-T therapy product candidate at a time.
Hematologic Malignancies
Our hematology program is designed to address patients who
are diagnosed with hematologic malignancies and can benefit from undergoing
allogeneic transplantation. Currently, 4 in every 10 patients that undergo a
transplant with reduced intensity conditioning (RIC) will relapse, at which
point there are limited treatment options and an 80% mortality rate over the
next two years. By treating residual disease with donor-derived TCR-T cells and
preventing relapse after transplant, our goal is to improve survival outcomes
and therefore expand the number of patients that could benefit from this
curative therapy.
Our product candidate, TSC-101, targets HA-2, an antigen
that is present on all blood cells, malignant or benign, in patients with the
HLA type A*02:01. When the patient receives a transplant from an
HLA-A*02-negative donor, their new, healthy donor-derived blood cells do not
present the HA-2 antigen. TSC-101 is administered shortly after the transplant
and targets and eliminates any residual patient-derived blood cells, including
any cancer cells, while sparing the new, healthy donor-derived blood cells.
As of September 2026, this program is on hold due to financing
constraints. Before this pause, we had had enrolled 7 patients on the treatment
arm the Phase 3 trial of TSC-101, the ALLOHA-2™
trial, for patients with acute myeloid leukemia (AML) or
myelodysplastic syndromes (MDS) undergoing allogeneic transplantation. We will
continue to treat and follow all 21 patients dosed with the commercial-ready
manufacturing process to allow the data to mature as we actively seek a
strategic partner that could continue to move the program forward.