TScan’s TCR-Ts Get RMAT Designation for Hematologic Malignancies
Eight patients receiving either TSC-100 or TSC-101 have been disease-free for a median of 10 months of follow-up.
The FDA has granted Regenerative Medicine Advanced Therapeutics designation to 2 of TScan Therapeutics’ T-cell receptor T-cell (TCR-T) therapies, TSC-100 and TSC-101, for the potential treatment of patients with acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), and myelodysplastic syndrome (MDS) undergoing allogeneic hematopoietic stem cell transplant (HCT) with reduced intensity conditioning.1
“We are delighted to receive FDA RMAT designation for both candidates in our heme program designed to treat patients with AML, ALL, and MDS undergoing allogeneic HCT with reduced intensity conditioning, based on encouraging initial data from the ALLOHA trial,” Chrystal U. Louis, MD, Chief Medical Officer, TScan, said in a statement.1
TSC-100 and TSC-101 target minor histocompatibility antigens HA-1 and HA-2, respectively, and are being evaluated in a phase 1/2 trial (NCT05473910) in patients who are HLA A*02:01-positive and either HA-1- or HA-2-positive, with donors who are negative for these antigens as part of TScan’s phase 1 hematological malignancies program.TSC-100 and TSC-101 are designed to eliminate all recipient hematopoietic cells persisting after transplant and ignore donor-derived cells, with the goal of increasing the cure rate of patients receiving HCT. Currently, around 40% of patients with AML, ALL, and MDS who undergo allogeneic haploidentical HCT with reduced intensity conditioning have a disease relapse within 2 years of transplant, and then face limited treatment options and poor prognosis.
“This is an important milestone that recognizes the transformative potential of our engineered TCR-T therapy candidates, TSC-100 and TSC-101, in multiple difficult-to-treat cancers. We look forward to working closely with the FDA in our ongoing commitment to deliver life-changing therapies to patients,” Louis added.1
As of May 13, 2024, TScan shared that, in the phase 1 trial, all 8 patients treated with TSC-100 or TSC-101 remained relapse-free with no detectable disease at a median of over 10 months of follow-up. In comparison, 2 of 8 patients in the control arm had disease relapse around 6 months post-transplant, with 1 death around 3 months later. A third patientrequired clinical intervention due to concerns of impending relapse, and a fourth died post-transplant.1
In addition to hematologic malignancies, TScan is also pursuing a TCR-T therapy program for solid tumors evaluating multiple TCR-Ts by HLA type and antigen. The company announced that it had treated the first patient with TSC-203-A0201, a PRAME-targeted TCR-T therapy, in a phase 1 trial (NCT05973487) in May. The patient has metastatic melanoma.2
“Dosing the first patient in our solid tumor program is a significant milestone for us, as we are now well underway with both of our core clinical programs,” Gavin MacBeath, PhD, Chief Executive Officer, TScan, said in a statement at that time.2 “There is a lot of enthusiasm for this trial, and we are already manufacturing TCR-T products for three more patients. We have 6 TCR-Ts cleared under existing IND applications for patient dosing in this program, and we plan to file additional IND applications to further expand the ImmunoBank across diverse targets and HLA types to broaden the reach of multiplex TCR-T therapy for solid tumors.”
