FDA Approves Tregzi for Adults With Hematological Malignancies

The FDA approved allogeneic regulatory T cell immunotherapy with hematopoietic stem and progenitor cells (HSPCs) and T cells-vldq (Tregzi; Orca Bio) for use in matched-donor hematopoietic stem cell transplantation (HSCT) with a myeloablative preparative regimen for hematopoietic and immunologic reconstitution and to improve chronic graft-versus-host disease (GVHD)-free survival (cGFS) in the treatment of adults with hematological malignancies.¹

Hematological malignancies, such as acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), and myelodysplastic syndromes (MDS), are blood cancers that can originate in the bone marrow and disrupt normal cell production. Despite therapeutic advancements, these diseases—particularly in adult and high-risk populations—remain associated with poor outcomes, high relapse rates, and significant treatment-related toxicities.¹

Tregzi is a personalized treatment manufactured for each individual patient using living cells from a matched donor. It uses HSPCs to reconstitute the immune system, highly purified regulatory T cells (Tregs) to suppress GVHD, and conventional T cells (Tcons) to accelerate immune reconstitution and produce graft-versus-leukemia (GVL) activity. Its approval is supported by data from the phase 3 clinical trial Precision-T (NCT05316701).^1,2

"Historically, surviving a blood cancer has often meant navigating serious, long-term effects that can shape patients’ lives well beyond treatment," Gwen Nichols, MD, executive vice president and chief medical officer at Blood Cancer United, said in a news release announcing Tregzi’s approval. “As a researcher, physician, and a patient advocate, it’s exciting that patients will have a new option that may change what life after transplant can look like, including the potential to support recovery and quality of life.”¹

Outcomes From the Precision-T Trial

Precision-T is a randomized phase 3 study that randomly assigned adult patients (N = 187) with acute leukemias or MDS undergoing myeloablative conditioning to receive either Tregzi with tacrolimus or a conventional allograft with tacrolimus and methotrexate (Tac/MTX), using granulocyte colony-stimulating factor–mobilized peripheral blood from HLA-matched donors. The trial’s primary end point was cGFS. Findings were published in Blood.^2,3

cGFS was found to be significantly higher in the Tregzi arm than in Tac/MTX (HR, 0.26; 95% CI, 0.14-0.47; P < .001). One-year estimates for cGFS were approximately 78.0% with Tregzi versus 38.4% with Tac/MTX. Additionally, cumulative incidence of moderate-to-severe cGVHD was approximately 12.6% and 44.0%, respectively (Gray test P < .001); overall survival was 93.9% and 83.1% (P = .12); GVHD-free and relapse-free survival was 63.1% and 30.9% (P < .001); and nonrelapse mortality (NRM) was 3.4% and 13.2% (P = .03).³

Notably, Tregzi met the primary end point of improved survival free from cGVHD compared with Tac/MTX prophylaxis. The investigators recommend that Tregzi should be considered a new therapeutic option with low toxicity for GVHD prophylaxis.³

“Developing this concept from early foundational research in our labs based upon the fundamental biology of regulatory T cells to it now receiving the first FDA approval for a therapy that utilizes highly purified Tregs is a defining moment for the transplant community," Robert Negrin, MD, professor of medicine, blood, and marrow transplantation at Stanford Medicine, said in the news release. "The peer-reviewed findings demonstrated this precision-engineered cell therapy delivered improved cGFS alongside less toxicity, including fewer serious infections and lower NRM."¹

The most common adverse reactions (incidence ≥ 20%) were mucositis, diarrhea, rash, viral infections, infections with unspecified pathogens, abdominal pain, vomiting, nausea, bacterial infections, hemorrhage, aGVHD, edema, and fungal infections.

Additional safety findings were consistent with previous studies. The most common grades 3 and 4 laboratory abnormalities observed in clinical trials were decreases in lymphocyte, platelet, leukocyte, neutrophil, and hemoglobin counts. Additionally, the cumulative incidence for grades 3 or 4 acute GVHD at day 180 or later with Tregzi was approximately 6% versus 10% with alloHSCT (HR 0.37; p = .044). Grade 3 infections were also less common with Tregzi, with a 1-year estimated incidence of 44% for Tregzi and 51% for alloHSCT.¹

"For transplant physicians, one of our greatest challenges has long been preserving the vital graft-versus-leukemia effect while minimizing the risk of GVHD and infection,” Miguel-Angel Perales, MD, medical oncologist and chief of the Adult Bone Marrow Transplant Service at Memorial Sloan Kettering Cancer Center, said. “The FDA approval of Tregzi signals a new era in transplant medicine. This precision-engineered cell therapy is built on the foundational principles established by our early CD34 cell selection work and can now be delivered at scale, equipping providers with a new option to reduce serious toxicities and improve treatment outcomes."¹

REFERENCES

1. 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. News release. June 30, 2026. July 1, 2026. https://orcabio.com/orca-bios-tregzi-receives-u-s-fda-approval-as-first-and-only-precision-engineered-cell-therapy-for-allogeneic-transplant-in-adults-with-hematological-malignanciesorca-bio-adds-east/

2. Precision-T: A Randomized Study of Orca-T in Recipients Undergoing Allogeneic Transplantation for Hematologic Malignancies (Orca-T). ClinicalTrials.gov identifier: NCT05316701. Updated March 4, 2026. Accessed July 1, 2026. https://clinicaltrials.gov/study/NCT05316701

3. Meyer EH, Salhotra A, Gandhi AP, et al. Orca-T vs allogeneic hematopoietic stem cell transplantation (Precision-T): a multicenter, randomized phase 3 trial. Blood. 2026;147(11):1168-1177. doi: 10.1182/blood.2025031313