Evaluating Orca-T versus Tac/MTX to prevent GVHD after alloHSCT
Meyer E, Salhotra A, Gandhi A, et al. Orca-T Versus Allogeneic Hematopoietic Stem Cell Transplantation (PRECISION-T): A Multicenter, Randomized Phase 3 Trial. Blood. 2025; (doi: 10.1182/blood.2025031313).
Phase III study results support Orca-T immunotherapy as a novel intervention and less toxic alternative to traditional tacrolimus and methotrexate (Tac/MTX) for GVHD prophylaxis following allogeneic hematopoietic stem cell transplantation. Evidence from the PRECISION-T trial demonstrates reduced toxicity and lower rates of adverse events are feasible with Orca-T, which uses purified donor Treg cells to prevent GVHD with substantially less immunosuppression. The research included 187 patients with acute leukemias or myelodysplastic syndrome, randomly assigned to conventional allograft with tacrolimus and methotrexate (Tac/MTX) or to Orca-T with tacrolimus. Outcomes favored Orca-T over Tac/MTX, including survival free from moderate-to-severe chronic GVHD of 78% at 1 year versus 38.4% with Tac/MTX. Orca-T also correlated to better overall survival, at 93.9% vs. 83.1%; lower incidence of moderate-to-severe cGVHD, at 12.6% vs. 44.0%; better GVHD and relapse-free survival, at 63.1% vs. 30.9%; lower non-relapse mortality, at 3.4% vs. 13.2%; and fewer serious infections.