FDA Approves Tregzi for Chronic GVHD-Free Survival in Blood Cancer

The U.S. Food and Drug Administration (FDA) has approved Tregzi (allogeneic regulatory T cell immunotherapy with HSPC and T cells-vldq), marking the first approval for a regulatory T (Treg) cell-based immunotherapy aimed at improving outcomes for adult patients with hematological malignancies.

The therapy, clinically known as Orca-T, is indicated for use in patients with high-risk blood cancers undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) with a myeloablative preparative regimen.

A novel approach to transplantation

For patients with blood cancers such as acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), and myelodysplastic syndrome (MDS), allo-HSCT remains a standard curative treatment. However, the procedure is often complicated by chronic graft-versus-host disease (GVHD), a condition where donor cells attack the recipient’s healthy tissues. Tregzi represents a precision-engineered approach designed to reduce this risk by carefully balancing the immune system during reconstitution.

The therapy is manufactured individually for each patient using cells collected from the peripheral blood of an 8/8 HLA-matched donor. Tregzi consists of three specific components: purified hematopoietic stem and progenitor cells (HSPCs), which reconstitute the immune system; purified Tregs to maintain immune tolerance and suppress GVHD; and conventional T cells (Tcons) to provide essential graft-versus-leukemia activity.

Pivotal trial data: The PRECISION-T study

The FDA’s decision — detailed in a notice from the agency and a news release from manufacturer Orca Bio — was supported by results from the Phase 3 PRECISION-T trial (NCT05316701), a randomized, open-label, multi-center study involving 187 patients across 19 treatment centers.

Patients were randomized to receive either Tregzi with single-agent tacrolimus or a standard allo-HSCT with a combination of tacrolimus and methotrexate.

The primary endpoint was chronic GVHD-free survival (cGFS) at one year, defined as the time from transplantation to death or the onset of moderate-to-severe chronic GVHD. The results demonstrated a significant benefit for those receiving the novel immunotherapy:

• Chronic GVHD-free survival: 78% for the Tregzi group compared to 38% for the standard transplant group (HR 0.26; p<0.00001).
• Incidence of chronic GVHD: 12.6% to 13% for Tregzi recipients versus 44% for standard transplant patients.
• Overall survival: 94% for Tregzi versus 83% for standard transplant.
• Non-relapse mortality: 3% for the Tregzi arm compared to 13% for the conventional arm.

Karim Mikhail, B.Pharm., M.S., Acting Director of the Center for Biologics Evaluation and Research (CBER), noted in the news release that the approval offers a "genuine new approach" to immune reconstitution while substantially reducing the risk of one of the most "feared and difficult-to-prevent complications" of transplantation.

Safety and nursing considerations

In the oncology nursing setting, monitoring for adverse reactions remains critical. The side effects observed with Tregzi were largely consistent with those expected during stem cell transplantation. The most common adverse reactions, occurring in at least 20% of patients, included mucositis, diarrhea, rash, and various viral, bacterial, and fungal infections. Grade 3 or 4 laboratory abnormalities frequently observed included decreases in lymphocyte, platelet, leukocyte, and neutrophil counts, as well as decreased hemoglobin.

No cases of graft failure were observed during the study period, and no patients experienced severe infusion reactions. However, the prescribing information includes warnings regarding the potential for graft failure, GVHD (including life-threatening cases), and serious infusion reactions. Nurses should premedicate patients with antipyretics and histamine antagonists before infusion and monitor closely for signs of hypersensitivity, which may manifest within minutes or several hours post-infusion.

Long-term monitoring is also advised for secondary malignancies and malignancies of donor origin, including posttransplantation lymphoproliferative disorder (PTLD), though no patients in the Tregzi clinical program have developed PTLD to date.

Transforming patient outcomes

The approval of Tregzi, which was granted orphan drug and regenerative medicine advanced therapy designations, validates a high-precision platform intended to rewrite patient outcomes. By reducing the toxicity associated with traditional transplants, clinicians hope to improve the long-term quality of life for survivors of high-risk blood cancers.

"Historically, surviving a blood cancer has often meant navigating serious, long-term effects," said Gwen Nichols, M.D., executive vice president and chief medical officer at Blood Cancer United, in the news release. Nichols emphasized that this new option may fundamentally change what life after transplant looks like for adult patients.

References

1. FDA approves new treatment that uses donor immune cells to prevent serious complications in blood cancer patients. U.S. Food and Drug Administration. June 30, 2026. Accessed July 1, 2026.
2. Orca Bio's TREGZI™ receives U.S. FDA approval as first and only precision-engineered cell therapy for allogeneic transplant in adults with hematological malignancies. Orca Bio. June 30, 2026. Accessed July 1, 2026.