Marker announces complete response in lymphoma patient treated with MT-601

Marker Therapeutics announces the preliminary results of the first participant treated with MT-601, its multi-tumor associated antigen-specific T cell product targeting 6 TAAs, in the Phase 1 multicenter APOLLO clinical trial. The APOLLO trial is investigating the safety and efficacy of MT-601 for the treatment of patients with lymphoma who have either failed or are ineligible to receive anti-CD19 CAR T cell therapy. This first APOLLO study participant had diffuse large B cell lymphoma and was enrolled into the Phase 1 dose escalation stage of the trial after failing 4 prior lines of therapy, including anti-CD19 CAR T cell therapy. After relapse following anti-CD19 CAR T cell therapy, the participant was treated with 2 doses of MT-601 at the 200 million cell dose level without prior lymphodepletion. MT-601 treatment was well tolerated with no reports of higher than Grade 1 treatment-related adverse events. The tolerability at this initial dose level is consistent with the favorable clinical safety profile and tolerability previously reported for other multiTAA-specific T cell products. Eight weeks after the 2nd infusion of MT-601, the participant demonstrated complete metabolic response based on PET-CT scans. Marker previously reported non-clinical proof-of-concept data that showed that MT-601 has the potential to eliminate lymphoma cells that are resistant to anti-CD19 CAR T cells, highlighting the therapeutic potential of MT-601 in vitro.