Orca Bio Gains FDA Approval for Tregzi in Matched Donor HSCT for Hematologic Malignancies

A three-component, sequentially dosed allogeneic cell therapy has cleared FDA BLA review, setting a manufacturing and regulatory precedent that QA directors and CMC leads at cell therapy facilities will need to benchmark against. Orca Bio's Tregzi received approval on June 30, 2026, for use in matched donor hematopoietic stem cell transplantation (HSCT) with a myeloablative preparative regimen, indicated for hematopoietic and immunologic reconstitution and to improve chronic graft-versus-host disease (cGVHD)-free survival in adults with hematological malignancies.

The dosing architecture is operationally significant: Tregzi comprises three discrete GMP-manufactured components, HSPCs, regulatory T cells (Tregs), and conventional T cells (Tcons), administered sequentially. HSPCs and Tregs are infused on day 0; Tcons follow on day +2 to day +3. Targeted cell doses are tightly specified: HSPCs at ≥1.0 × 10⁶ viable cells/kg, Tregs at 1.3–3.5 × 10⁶ viable cells/kg, and Tcons at 1.3–6.9 × 10⁶ viable cells/kg. For manufacturing teams, this multi-component release model introduces layered sterility assurance requirements and release testing timelines that must align with a narrow clinical administration window.

Efficacy data from the Precision-T trial (NCT05316701), a multicenter, open-label, randomized controlled study in 187 adults with acute leukemias or myelodysplastic syndrome, supported the submission. Median cGVHD-free survival was not estimable in the Tregzi arm versus 7.3 months in the unmanipulated allograft control arm (HR = 0.26; 95% CI: 0.14, 0.47; P <.00001). The 12-month cumulative incidence of moderate-to-severe cGVHD was 12.6% for Tregzi versus 44.0% for control. All 88 Tregzi-treated patients achieved neutrophil engraftment within 28 days, a critical engraftment endpoint with direct implications for post-infusion monitoring protocols.

The safety profile includes warnings and precautions for graft failure, GVHD, infusion reactions, secondary malignancies, malignancies of donor origin, and transmission of infectious agents, each carrying documentation and pharmacovigilance obligations under 21 CFR Part 211 and applicable biologics regulations. The most common adverse reactions (incidence ≥20%) included mucositis, diarrhea, rash, viral and bacterial infections, and acute GVHD. Tregzi carried priority review, orphan drug designation, and regenerative medicine advanced therapy (RMAT) designation through the review cycle.

The application used the FDA's voluntary Assessment Aid, a submission tool that regulatory affairs teams should note as an emerging mechanism for complex biologics reviews. Full prescribing information will be posted to the 2026 Biological License Application Approvals page.

The three-component sequential release model now on file with FDA will serve as a reference architecture for allogeneic cell therapy CMC submissions entering the review queue.

Source: FDA Drugs RSS Feed via fda.gov, June 30, 2026.