News|Articles|July 1, 2026

Orca-T Gains FDA Approval for Matched Donor Stem Cell Transplant

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Key Takeaways

Orca-T integrates HSPCs for reconstitution, highly purified Tregs for GVHD suppression, and Tcons to accelerate immune recovery and preserve graft-versus-leukemia activity via a matched-donor, patient-specific manufacturing workflow.
Precision-T randomized 187 adults (AML/ALL/MDS/MPAL) to Orca-T plus tacrolimus vs unmanipulated graft plus tacrolimus/methotrexate, using blinded adjudication for NIH-defined moderate-to-severe cGVHD.
cGVHD-free survival improved (12-month 78% vs 38%; HR 0.26), with substantially reduced 12-month moderate-to-severe cGVHD (12.6% vs 44.0%; HR 0.19) versus conventional alloHSCT.
Safety profile included expected transplant toxicities; grade ≥3 infections and grade 3/4 acute GVHD were lower with Orca-T, and no posttransplant lymphoproliferative disorder occurred in treated patients.
Administration uses day 0 HSPCs and Tregs followed by day +2/+3 Tcons, and the regulatory pathway included priority review plus orphan drug and RMAT designations.

FDA approves Orca-T precision Treg cell therapy for matched donor transplants, cutting chronic GVHD risk and boosting survival in blood cancers.

The FDA has granted approval to allogeneic regulatory T cell–based immunotherapy with hematopoietic stem and progenitor cell (HSPC) and T cells-vldq (Tregzi; Orca-T) for use in matched donor hematopoietic stem cell transplantation (HSCT) with a myeloablative preparative regimen.¹ The approval covers hematopoietic and immunologic reconstitution and improvement of chronic graft-vs-host disease (cGVHD)–free survival in adults with hematologic malignancies.^1,2

"Simply stated, the unmet need in allotransplantation is to reduce the risk of graft-vs-host disease without increasing the risk of infections or relapse," Precision-T investigator Caspian Oliai, MD, MS, a medical oncologist and hematologist and medical director of the UCLA Bone Marrow Transplantation Stem Cell Processing Center, told The American Journal of Managed Care^®.³

What is Orca-T and how does it work?

Orca-T is a personalized, precision-engineered cell therapy manufactured for each patient using living cells from a matched donor.² It consists of 3 sequentially administered components: 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 generate graft-vs-leukemia activity. Orca Bio describes the approval as the first for a therapy built on highly purified Tregs, and the company's platform uses single-cell precision to design products intended to replace a patient's diseased blood and immune system with a healthy one.

What did the Precision-T trial show?

The approval was based on efficacy and safety data from Precision-T (NCT05316701), a randomized, open-label, multicenter phase 3 trial that compared Orca-T with conventional allogeneic HSCT (alloHSCT) in adults with acute leukemias or myelodysplastic syndrome (MDS).¹ In total, 187 patients were randomized to receive either Orca-T (n = 93) followed by single-agent tacrolimus (TAC) prophylaxis, or unmanipulated allograft (n = 94) followed by TAC plus methotrexate prophylaxis. The trial population had a median age of 43.6 years (range, 19-65) and included patients with acute myeloid leukemia, acute lymphoblastic leukemia, MDS, and mixed-phenotype acute leukemia.

The primary end point was cGVHD-free survival (cGFS), defined as time from HSCT to death from any cause or moderate to severe cGVHD per NIH consensus criteria, as determined by a blinded, independent adjudication committee. Median cGFS was not estimable in the Orca-T arm compared with 7.3 months (95% CI, 6.3-15.5) in the control arm (HR, 0.26; 95% CI, 0.14-0.47; P < .00001). At 12 months, cGFS was reported at 78% with Orca-T vs 38% with alloHSCT.²

The cumulative incidence of moderate to severe cGVHD at 12 months was 12.6% (95% CI, 5.3%-23.1%) with Orca-T vs 44.0% (95% CI, 31.3%-56.1%) with alloHSCT (HR, 0.19; 95% CI, 0.08-0.43; P = .00002).¹ Additional 12-month outcomes reported by the manufacturer included overall survival of 94% with Orca-T vs 83% with alloHSCT, GVHD-free and relapse-free survival of 63% vs 31%, and nonrelapse mortality of 3% vs 13%.² All 88 evaluable patients (100%) treated with Orca-T achieved a neutrophil count of 500/mm within 28 days of infusion, and 60.2% (53 of 88) sustained that recovery across 3 consecutive days.¹

What are the safety considerations?

The most common adverse reactions (incidence ≥ 20%) were mucositis, diarrhea, rash, viral infections, infections of unspecified pathogen, abdominal pain, vomiting, nausea, bacterial infections, hemorrhage, acute GVHD, edema, and fungal infections. Grade 3 or higher infections occurred less frequently with Orca-T than with alloHSCT (estimated 1-year incidence, 44% vs 51%), and grade 3/4 acute GVHD at day 180 was lower with Orca-T (6% vs 10%; HR, 0.37; P = .044).²

Prescribing information carries warnings and precautions for graft failure, GVHD, infusion reactions, secondary malignancies and malignancies of donor origin, and transmission of infectious agents.^1,2 No patient treated with Orca-T in the trial developed posttransplantation lymphoproliferative disorder.²

What is the recommended dosing?

Orca-T's 3 components are administered sequentially: HSPCs (≥ 1.0 × 10⁶ viable cells/kg) and Tregs (1.3 × 10⁶ to 3.5 × 10⁶ viable cells/kg) are given intravenously on day 0, followed by Tcons (1.3 × 10⁶ to 6.9 × 10⁶ viable cells/kg) on day +2 to day +3.¹ The application was reviewed under the FDA's Assessment Aid and received priority review, orphan drug designation, and regenerative medicine advanced therapy designation.

What have experts said about the approval?

"For transplant physicians, one of our greatest challenges has long been preserving the vital graft-vs-leukemia effect while minimizing the risk of GVHD and infection," Miguel-Angel Perales, MD, chief of the Adult Bone Marrow Transplant Service at Memorial Sloan Kettering Cancer Center, said in a statement.² He noted that the therapy builds on foundational 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."

Robert Negrin, MD, of Stanford Medicine, called the approval "a defining moment for the transplant community," pointing to peer-reviewed findings showing improved GVHD-free survival alongside less toxicity, including fewer serious infections and lower nonrelapse mortality. Gwen Nichols, MD, chief medical officer at Blood Cancer United, said the option "may change what life after transplant can look like, including the potential to support recovery and quality of life" for patients who have historically faced serious, long-term effects after blood cancer treatment.

Results from Precision-T were published in Blood in December 2025, and the trial enrolled patients across 19 treatment centers in the US.

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