Drug Update · Oncology

FDA Approves Tregzi for Matched-Donor HSCT: 78% vs 38.4% cGFS

September 05, 2026

Approval date

June 30, 2026

Trial

Precision-T (randomized, controlled Phase 3)

Randomized N

187 (Tregzi n=93; control n=94)

One-year cGFS

78% with Tregzi vs 38.4% with unmanipulated allograft [1][5]

Primary endpoint HR

HR 0.26; 95% CI 0.14-0.47 [5]

Clinical Perspective

Hematologists, transplant physicians, and transplant pharmacists caring for adult patients with hematological malignancies who are proceeding to matched-donor myeloablative HSCT are directly affected by this approval ^[2]^[3]. The Precision-T trial data support using Tregzi in this population to improve chronic GVHD-free survival, including a one-year cGFS of 78% versus 38.4% with an unmanipulated allograft and a primary-event HR of 0.26 ^[1]^[4]. Will Tregzi’s benefit extend to nonmyeloablative regimens, mismatched donors, or broader transplant populations not studied in Precision-T?

Dr. Meera Pillai, MBBS, MD (General Medicine), DM (Medical Oncology) · Oncology

The U.S. Food and Drug Administration approved Tregzi (allogeneic regulatory T cell immunotherapy with HSPC and T cells-vldq, Orca Bio) on June 30, 2026 for use in matched donor hematopoietic stem cell transplantation with a myeloablative preparative regimen to improve chronic graft-versus-host disease (cGVHD)-free survival in adults with hematological malignancies ^[2]^[3]. The approval was based on the Precision-T randomized trial in which patients who received Tregzi had higher one-year chronic GVHD-free survival (78% vs 38.4%) and a hazard ratio for the primary endpoint of HR 0.26 (95% CI 0.14-0.47) ^[1]^[4].

Clinical Context

Tregzi is an allogeneic regulatory T (Treg) cell-based immunotherapy composed of hematopoietic stem and progenitor cells (HSPCs), purified regulatory T cells (Tregs), and conventional T cells (Tcons) manufactured from a closely HLA-matched donor ^[4]. The product is intended for matched donor (8/8 HLA match) hematopoietic stem cell transplantation (HSCT) administered after a myeloablative preparative regimen to support hematopoietic and immunologic reconstitution and to improve chronic GVHD-free survival in adults with hematologic malignancies, including acute leukemias and myelodysplastic syndromes ^[2]^[3]^[4]. Orca Biosystems (Orca Bio) is the manufacturer; the application received priority review and was granted orphan drug and regenerative medicine advanced therapy designations during the review ^[2]. The FDA’s approval cites internally consistent randomized trial results that the agency determined show clinical benefit in the indicated population ^[1]^[2].

Key Findings

The Precision-T trial showed that Tregzi reduced the risk of death or moderate-to-severe chronic GVHD versus an unmanipulated allograft (HR 0.26; 95% CI 0.14-0.47) as the trial’s primary endpoint, chronic GVHD-free survival (cGFS) ^[4].
At one year after HSCT, 78% of patients who received Tregzi achieved chronic GVHD-free survival versus 38.4% of patients who received an unmanipulated allograft; these one-year rates were reported by the FDA as supporting the approval ^[1]^[4].
After accounting for death as a competing risk, 12.6% of patients who received Tregzi developed serious chronic GVHD within one year compared with 44% of patients who received the unmanipulated allograft ^[1].
The randomized phase 3 Precision-T study randomized 187 adults with acute leukemias or myelodysplastic syndrome to Tregzi (n=93) or unmanipulated allograft (n=94) and the primary endpoint was adjudicated by a blinded independent committee ^[2]^[4].

Safety & Tolerability

Abdominal pain ^[2].
Vomiting ^[2].
Nausea ^[2].
Bacterial infections ^[2].
Hemorrhage ^[2].
Acute GVHD ^[2].
Edema ^[2].
Fungal infections ^[2].
Graft failure (warning/precaution in prescribing information) ^[2].
Infusion reactions (warning/precaution in prescribing information) ^[2].
Secondary malignancies and malignancies of donor origin (warning/precaution in prescribing information) ^[2].
Transmission of infectious agents (warning/precaution in prescribing information) ^[2].

Study Design

Precision-T (NCT05316701) was a multicenter, open-label, randomized, controlled phase 3 study in adults with acute leukemia in CR/CRi or myelodysplastic syndrome that randomized 187 patients to receive either Tregzi (n=93) with single-agent tacrolimus prophylaxis or an unmanipulated allograft (n=94) with tacrolimus plus methotrexate prophylaxis ^[2]^[4]. The primary efficacy outcome measure was chronic GVHD-free survival (cGFS), defined as time from HSCT to death by any cause or first occurrence of moderate-to-severe cGVHD per NIH consensus criteria and adjudicated by an independent endpoint committee ^[2]^[4]. The study demonstrated statistically significant improvement in cGFS and time to moderate/severe cGVHD with Tregzi ^[4].

FAQ

Q1 What is Tregzi approved for?

Tregzi (allogeneic regulatory T cell immunotherapy with HSPC and T cells-vldq) is approved for use in matched donor hematopoietic stem cell transplantation with a myeloablative preparative regimen for hematopoietic and immunologic reconstitution and to improve chronic graft-versus-host disease-free survival in adults with hematological malignancies. The approval specifies use in matched donor HSCT with a myeloablative preparative regimen.

Q2 How does Tregzi work?

Tregzi is derived from mobilized peripheral blood of an HLA-matched donor and contains hematopoietic stem and progenitor cells (HSPCs), purified regulatory T cells (Tregs), and conventional T cells (Tcons). Tregs are administered prior to Tcons to control GVHD and promote immune reconstitution, while Tcons are given later to accelerate immune recovery; HSPCs engraft in bone marrow to restore hematopoiesis. The exact mechanism of Treg-mediated effects is not fully understood but nonclinical studies indicate suppression of Tcon activation and improved immune reconstitution.

Q3 What is the recommended dose of Tregzi?

Tregzi is provided as patient-specific infusion bags for intravenous administration and the approved product consists of three sequentially administered components with target viable cell dose ranges: HSPC ≥1.0 × 10^6 viable cells/kg administered IV on Day 0; Tregs 1.3 × 10^6 to 3.5 × 10^6 viable cells/kg administered IV on Day 0 immediately after HSPCs; and Tcons 1.3 × 10^6 to 6.9 × 10^6 viable cells/kg administered IV on Day +2 to +3. The product is provided in four infusion bags and requires administration after a myeloablative preparative regimen. Clinicians should consult current prescribing information for full dosing guidance. Clinicians should consult current prescribing information for complete dosing guidance.

Q4 What are the side effects of Tregzi?

Adverse events and warnings explicitly reported in the prescribing information and FDA documents include abdominal pain, vomiting, nausea, bacterial infections, hemorrhage, acute GVHD, edema, fungal infections, graft failure, infusion reactions, secondary malignancies including malignancies of donor origin, and transmission of infectious agents. The prescribing information includes warnings and precautions covering graft failure, GVHD, infusion reactions, secondary malignancies and donor-origin malignancies, and infectious transmission.

FDA Approves Tregzi for Matched-Donor HSCT: 78% vs 38.4% cGFS

Direct Clinical Takeaway & Evidence Summary

FDA Approves Tregzi for Matched-Donor HSCT: 78% vs 38.4% cGFS

Clinical Perspective

Clinical Context

Key Findings

Safety & Tolerability

Study Design

FAQ

References

Cite & Reference This Monograph

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