Conference Abstracts - 2026 National Summit on Hematologic Cancers
Vol. 6, Issue Supplement 2, 2026 · S1-4
Orca-T improves Chronic Graph-versus-Host Disease Free in Patients with a Broad Range of Demographic and Clinical Variables: Results of Randomized, Phase 3 Trial
Everett Meyer, MD,Amandeep Salhotra, MD,Arpita Gandhi, MD,Jeremy Pantin, MD,Rasmus Hoeg, MD,Alexandra Gomez-Arteaga, MD,Rawan Faramand, MD,Roni Tamari, MD,Edmund Waller, MD,Satyajit Kosuri, MD,Antonio Jimenez Jimenez, MD,Jennifer Holter-Chakrabarty, MD,Bhagirathbhai Dholaria, MD,Yi-Bin Chen, MD,Betty Hamilton, MD,John Magenau, MD,Alireza Eghtedar, MD,Anna Pavlova, MD,J. Scott McClellan, MD,Katie Gatwood, PharmD,Caspian Oliai, MD,Robert Negrin, MD,Sagar Patel, MD
Submission received: 2026-08-16 / Accepted: 2026-08-25 / Published: 2026-10-02
Abstract
Background
Orca-T is an allogeneic T-cell immunotherapy using purified donor regulatory T cells to prevent graft-versus-host disease (GVHD). The randomized Ph3 Precision-T trial (NCT05316701) showed improved moderate-to-severe chronic GVHD-free survival with Orca-T versus standard-of-care transplantation with tacrolimus+methotrexate prophylaxis. This analysis examines outcomes in prespecified patient subgroups from Precision-T.
Methods
In the Ph3 randomized trial, 88 patients received Orca-T and 94 patients received Tac/MTX. Orca-T was produced in a centralized GMP facility and administered in 19 centers across the U.S. Patients were ≤65 years old; had a diagnosis of AML, ALL, MPAL, or MDS with intermediate or high disease risk index scores. Patients received a MAC regimen (busulfan/fludarabine/thiotepa or a TBI-based regimen) and had an 8/8 HLA matched donor. Subgroups of patients were identified based on differences in demographic and pretreatment clinical variables including recipient age and sex, donor type, disease type, disease risk, and conditioning regimen. cGFS (the primary endpoint) and GRFS (survival free of aGVHD grades 3-4, moderate-to-severe cGVHD, and relapse) (a secondary endpoint) were compared between treatment groups for each subsets.
Results
Per the statistical analysis plan, the 56th cGFS event triggered a primary analysis of the Ph3 study at a median follow-up of 9 months. The study population had a median age of 43.5 years (range 19 to 65) and 35% were 50 to 65 y/o. Primary diseases included AML (53%), ALL (30%), MPAL (3%) and high-risk MDS (14%). Donors were 8/8 HLA-matched (53% sibling, 47% unrelated). In the intention-to-treat cohorts, Orca-T had a significantly higher cGFS rates at 1-year of 78% (95% CI: 65%, 87%) for Orca-T and 38% (95% CI: 26%, 51%) for Tac/MTX with a HR 0.26; 95% CI: 0.14, 0.47, p <0.00001). The HR for GRFS also favored Orca-T at 0.37 (0.23, 0.60). A total of 94% Orca-T patients were alive at 1-year vs 83% of Tac/MTX patients (HR 0.49; 95% CI 0.20, 1.22, p=0.12). One-year RFS was comparable (76% for Orca-T vs. 74% for Tac/MTX) while NRM favored Orca-T (3.4% vs.14%, respectively). Subset analyses for demographic and clinical variables were analyzed, for which the HR and 95% CI for cGFS and GRFS were as follows in Tables 1 & 2. For patients >50y: one-year rates of OS were 93.6% (77%, 98%) for Orca-T (n=31) versus 80% (61%, 91%) for Tac/MTX (n=32), HR = 0.48 (0.12, 1.89).
Conclusion
Orca-T demonstrated improved clinical outcomes overall and across subgroups with varied demographic and clinical features. These data suggest that the benefit of Orca-T extends to older patients and those with high-risk disease.