No graft failures were observed within the study period, and no patient experienced a severe reaction during the Tregzi infusion.
The US Food and Drug Administration (FDA) has cleared Tregzi (allogeneic regulatory T-cell [Treg] immunotherapy, formerly known as Orca-T) as a novel approach to traditional allogeneic hematopoietic stem cell transplantation for adults with higher-risk blood cancers such as acute lymphoblastic leukemia (ALL)
According to an FDA news release, the product is approved to improve survival free of chronic graft-versus-host disease (GVHD), a complication that remains among the hardest to prevent after transplant
The treatment is assembled from 3 distinct cell populations: hematopoietic stem and progenitor cells (HSPCs), Tregs, and conventional T cells. All cells are harvested from the mobilized peripheral blood of a single related or unrelated donor who is 8/8 HLA-matched. Tregs act as regulators of the immune system, keeping responses in balance and preserving tolerance. Their inclusion is meant to reduce the chance of chronic GVHD, while HSPCs help the patient rebuild blood and immune function after transplant.
Approval was based on the PRECISION-T study, which randomly assigned 187 adults with blood cancers, among them ALL and myelodysplastic syndromes (MDS), to either the combination T-cell therapy or a conventional stem cell transplant. Investigators tracked chronic GVHD-free survival over 2 years, counting either death from any cause or a first episode of moderate or severe chronic GVHD as an event
One year after transplant, 78% of the T-cell-based therapy group remained alive and free of moderate or severe chronic GVHD, against 38.4% of those given a standard transplant. Treating death as a competing risk, serious chronic GVHD arose in 12.6% of the T-cell-based therapy recipients at 1 year, compared with 44% in the comparison arm
Chronic GVHD “has long been one of the most feared and difficult-to-prevent complications” for patients needing stem cell transplantation, said Karim Mikhail, acting director of the FDA’s Center for Biologics Evaluation and Research
Adverse events with the new treatment largely mirrored what is typically seen after transplantation, primarily infections. No severe infusion reactions occurred, and no patient developed graft failure over the study period. The therapy holds both Orphan Drug and Regenerative Medicine Advanced Therapy designations
This article originally appeared on Rare Disease Advisor
FDA approves new treatment that uses donor immune cells to prevent serious complications in blood cancer patients. News release. US Food and Drug Administration; June 30, 2026
