FDA Approves Orca-T (Tregzi): A New Era of Precision Cell Therapy in Allogeneic Stem Cell Transplantation

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The FDA has approved Tregzi™ (formerly Orca-T®, Orca Bio), the first precision-engineered regulatory T-cell (Treg)-based allogeneic cell therapy for adults undergoing matched-donor hematopoietic stem cell transplantation (HSCT) for hematologic malignancies. Rather than simply replacing diseased bone marrow, Orca-T is designed to reconstruct the immune system with a carefully selected population of donor hematopoietic stem cells, conventional T cells, and purified regulatory T cells that reduce the risk of chronic graft-versus-host disease (GVHD) while preserving immune reconstitution and graft-versus-leukemia activity. The therapy was approved on June 30, 2026, based on the Phase 3 PRECISION-T trial, in which approximately 78% of treated patients were alive and free of chronic GVHD at one year, compared with 38% receiving conventional transplantation. For Animedix, this approval represents more than another cell therapy milestone—it validates the growing concept that precision medicine can be achieved by engineering the composition of the immune system itself, rather than relying solely on post-transplant immunosuppression. By selectively enriching immune cell subsets before infusion, Orca-T illustrates how cellular engineering can alter biological outcomes through rational control of immune balance. Want to understand how Orca-T works? Before reading further, we encourage you to watch our April 2026 Animedix Mechanism of Action (MOA) video on Orca-T, which explains how regulatory T cells help prevent GVHD while preserving the beneficial anti-leukemia effects of donor immune cells. That foundational overview provides the mechanistic context behind today's landmark FDA approval.