By VETTAPHARMA reporter – Derek Roche: The U.S. Food and Drug Administration (FDA) has approved Orca Biosystems’ Tregzi, the first regulatory T (Treg) cell-based immunotherapy to improve chronic graft-versus-host disease (GVHD)-free survival in adults with high-risk blood cancers undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT).
The approval introduces a first-in-class donor-derived cellular immunotherapy that significantly reduces the risk of chronic GVHD—one of the most serious long-term complications following stem cell transplantation—while preserving the curative potential of transplantation.
Tregzi is indicated for adults with high-risk blood cancers receiving an allogeneic hematopoietic stem cell transplant from an 8/8 HLA-matched related or unrelated donor following myeloablative conditioning. The therapy is composed of three purified donor-derived cell populations—hematopoietic stem and progenitor cells (HSPCs), regulatory T (Treg) cells, and conventional T (Tcon) cells—designed to reconstitute the patient’s immune system while promoting immune tolerance and reducing the risk of chronic GVHD.
The approval was supported by the pivotal PRECISION-T randomized controlled trial, which enrolled 187 adults with high-risk blood cancers, including acute leukemia and myelodysplastic syndrome. Participants were randomized to receive either Tregzi or a standard allogeneic stem cell transplant. The primary endpoint was chronic GVHD-free survival, defined as the time from transplantation to the earliest occurrence of moderate or severe chronic GVHD or death from any cause within two years after transplantation.
At one year, 78.0% of patients treated with Tregzi achieved chronic GVHD-free survival compared with 38.4% of patients receiving a standard transplant. After accounting for death as a competing risk, 12.6% of patients receiving Tregzi developed moderate or severe chronic GVHD within one year, compared with 44.0% in the standard transplant group. According to the FDA, the randomized trial produced highly persuasive and internally consistent results, demonstrating clinically meaningful benefit in the indicated patient population.
The safety profile was generally consistent with that expected following allogeneic hematopoietic stem cell transplantation, with infections representing the most common adverse events. No severe infusion reactions and no cases of graft failure were reported during the study period.
Before approval, Tregzi received both Orphan Drug and Regenerative Medicine Advanced Therapy (RMAT) designations from the FDA, recognizing its potential to address a significant unmet medical need in transplantation.
Quick FAQs
1. What Is Tregzi?
Tregzi is a donor-derived cellular immunotherapy comprising hematopoietic stem and progenitor cells, regulatory T cells, and conventional T cells. It is designed to improve chronic graft-versus-host disease-free survival in adults undergoing allogeneic hematopoietic stem cell transplantation.
2. What Happened?
The FDA approved Orca Biosystems’ Tregzi as the first regulatory T-cell-based immunotherapy to improve chronic graft-versus-host disease-free survival in adults with high-risk blood cancers undergoing allogeneic hematopoietic stem cell transplantation.
3. What Is The PRECISION-T Study?
PRECISION-T was a randomized controlled clinical trial involving 187 adults with high-risk blood cancers. It compared Tregzi with a standard stem cell transplant, with the primary endpoint measuring chronic graft-versus-host disease-free survival over two years after transplantation.
4. What Is Chronic Graft-Versus-Host Disease?
Chronic graft-versus-host disease is a potentially life-threatening complication of allogeneic stem cell transplantation in which donor immune cells attack the recipient’s healthy tissues, leading to chronic organ damage, disability, and reduced quality of life.
5. What Were The Key Results?
At one year, 78.0% of patients treated with Tregzi achieved chronic graft-versus-host disease-free survival compared with 38.4% receiving a standard transplant. The incidence of moderate or severe chronic graft-versus-host disease was 12.6% with Tregzi versus 44.0% with standard transplantation.
6. Why Is This Important?
Tregzi is the first FDA-approved regulatory T-cell therapy for patients undergoing allogeneic hematopoietic stem cell transplantation, introducing a novel cellular immunotherapy that significantly reduces chronic graft-versus-host disease and has the potential to improve long-term transplant outcomes for adults with high-risk blood cancers.
