Tregzi Approved for Adults who have Hematologic Malignancies Receiving Allogeneic Stem Cell Transplantation
On June 30, 2026, the US Food and Drug Administration (FDA) approved Tregzi™ [allogeneic regulatory T cell immunotherapy with hematopoietic stem and progenitor cells (HSPCs) and T cells-vldq – 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 (cGVHD)-free survival, in adults who have hematological malignancies. Tregzi is an engineered cell therapy manufactured from mobilized peripheral blood collected from an HLA-matched donor. It comprises three donor-derived cellular components: purified HSPCs, regulatory T cells (Tregs), and conventional T cells (Tcons) designed to promote hematopoietic and immune reconstitution while reducing the risk of chronic graft-versus-host disease (GVHD). The targeted doses are HSPCs at a dose of 1.0 × 10⁶ viable cells/kg or greater, Tregs 1.3 × 10⁶ to 3.5 × 10⁶ viable cells/kg, and Tcons 1.3 × 10⁶ to 6.9 × 10⁶ viable cells/kg. Following a myeloablative preparative regimen, HSPCs and Tregs are administered sequentially on treatment day zero, followed by Tcons on day two through day three. Orca Bio has stated that Tregzi can be manufactured and delivered within approximately 72 hours from cell collection to product administration, with low reported manufacturing failure rates. The wholesale acquisition cost (WAC) is $428,000 for a one-time treatment. Orca Bio is planning a staged US rollout immediately, beginning at select authorized transplant centers (ATCs) and expanding to approximately 25 centers by the end of 2026. Distribution plans are unknown at this time. For complete prescribing information, see here.
At a Glance
- Brand Drug: Tregzi™ (allogeneic regulatory T cell immunotherapy with HSPCs and T cells-vldq)
- Manufacturer: Orca Bio
- Date Approved: June 30, 2026
- Indication: For use in matched donor HSCT with a myeloablative preparative regimen, for hematopoietic and immunologic reconstitution and to improve cGVHD-free survival, in the treatment of adults who have hematologic malignancies.
- Dosage Forms Available: Personalized cell therapy suspension for intravenous (IV) infusion supplied as four separate infusion bags labeled for a specific patient: HSPCs, Tregs, Tcons, and Tcon diluent.
- Launch Date: Orca Bio is planning a staged US rollout, beginning at select transplant centers and expanding to approximately 25 centers by the end of 2026.
- Estimated Annual Cost: $428,000 WAC for a one-time treatment.
- FDA Designation: Regenerative Medicine Advanced Therapy (RMAT), Orphan Drug and Priority Review.
- Allogeneic HSCT is a potentially curative treatment option for adults who have high-risk hematologic malignancies, but cGVHD remains a serious post-transplant complication in which donor immune cells attack recipient tissues. Tregzi is designed to support hematopoietic and immunologic reconstitution while reducing the risk of cGVHD.
- Approximately 10,400 allogeneic HSCTs were performed in 2024. Chronic GVHD is estimated to occur in about 30% to 40% of allogeneic HSCTs recipients, depending on treatment-related factors such as donor type and conditioning regimens. cGVHD can affect multiple organs and contribute to long-term morbidity, prolonged immunosuppression, and impaired quality of life after transplant.
- Compared with acute GVHD, which typically occurs in the first 100 days after allogeneic HSCT and most often affects the skin, GI tract and liver, cGVHD usually develops after 100 days and can involve a broader range of organs, including the skin, eyes, mouth, liver, lungs and joints.
- Approval was supported by the phase III PRECISION-T study in 187 adults who had hematologic malignancies undergoing matched donor HSCT. In the study, cGVHD-free survival was higher with Tregzi than with the control group at one year, 78% versus 38%, respectively. Tregzi also reduced the cGVHD rate to 13% compared with 44% in the control. All evaluable patients in the Tregzi group achieved neutrophil recovery within 28 days of infusion.
- The most common adverse reactions with Tregzi were mucositis, diarrhea, rash, viral infections, abdominal pain, vomiting, nausea, infections, hemorrhage, acute GVHD, edema, and fungal infections. The most common laboratory abnormalities were decreased lymphocyte, platelet, leukocyte and neutrophil counts, as well as decreased hemoglobin levels.
- Other GVHD prevention strategies include posttransplant cyclophosphamide-based regimens, calcineurin inhibitor/methotrexate-based regimens and abatacept-based prophylaxis in selected transplant settings. Ryoncil® (remestemcel-L-rknd; Mesoblast) is approved for pediatric steroid-refractory acute GVHD, so it will not compete directly with Tregzi.