On June 30th, 2026, the FDA approved Orca‑T as the first FDA-approved precision-engineered regulatory T-cell therapy for ablative matched donor stem cell transplant in adults with hem malignancies. Now, this is a significant advancement in transplant medicine and introduces a novel approach to reducing chronic graft-versus-host disease or GVHD, while preserving the benefits of allogeneic transplantation.

So what is Orca‑T? Well, Orca‑T is a donor-derived precision-engineered cellular graft composed of three components. First, you have your regulatory T-cells or Tregs, and these are specialized immune cells that help suppress excessive immune responses, and play a central role in preventing GVHD. Then you have your conventional T-cells or your Tcons, and these include CD4 positive and CD8-positive T-cells. Now, these cells support immune recovery and are intended to preserve graft versus leukemia effect, while helping the immune system recognize and eliminate residual malignant cells. Now, it's important to note the dose of the conventional T-cells is carefully controlled and lower than what is typically delivered in a standard unmanipulated allogeneic graft. And then you have your stem cells. And these are responsible for reestablishing blood cell production and rebuilding the patient's immune system after transplant. Now, the goal is to create a more balanced immune response following transplantation.

So the FDA approved Orca‑T based on the results from the randomized phase three precision T study. And this trial enrolled adults 18 to 65 years of age undergoing their first allogeneic stem cell transplant from an HLA matched donor, following myeloablative conditioning.

Now, eligible diagnosises included AML, ALL, mixed phenotype acute leukemia in remission, and selective patients with MDS. Patients receiving Orca‑T were treated with single-agent tacrolimus for GVHD prophylaxis. While the control group received the conventional transplantation with tacrolimus and methotrexate. Now, the primary endpoint was chronic GVHD-free survival. Defined as the time from transplant until either death from any cause, or the development of moderate to severe chronic GVHD.

At 12 months, chronic GVHD-free survival was 78% in patients receiving Orca‑T compared with 38% in patients receiving conventional transplantation. Patients receiving Orca‑T also experienced lower non-relapse mortality. And the study reported improved immune reconstitution and immune recovery. Now, these findings suggest that Orca‑T can significantly reduce chronic GVHD while maintaining the therapeutic benefits of an allogeneic transplantation.

Research continues to explore the role of Orca‑T in additional transplant settings. This year at Tandem, investigators reported encouraging results from a single-center phase one study. Evaluating Orca‑T in patients with AML, ALL, MDS, and MPN such as myelofibrosis receiving reduced intensity conditioning. Now, compared with the historical cohort treated with post-transplant cyclophosphamide, Orca‑T was associated with improved overall survival and GVHD-free survival at two years. In addition, the ongoing phase two SERENE-T trial is evaluating Orca‑T in patients with AML and MDS undergoing reduced intensity or non-myeloablative conditioning. Now, these studies are going to help us determine the broader applicability of Orca‑T across the transplant populations.

So overall, we know Orca‑T is a personalized precision engineered cell therapy that combines stem cells, the Tregs, and those controlled dose of Tcons to optimize transplant outcome. And by significantly improving chronic GVHD-future survival, supporting immune recovery, and preserving the therapeutic benefits of allogeneic transplantation, Orca‑T represents an important innovation in matched donor stem cell transplantation.