Omidubicel-onlv Transplantation for Hematologic Malignancies: Results of a Multicenter Expanded Access Program

Omidubicel-onlv is an FDA-approved, nicotinamide-modified, allogeneic hematopoietic progenitor cell therapy derived from umbilical cord blood (UCB). A phase 3 study demonstrated improved hematopoietic recovery and decreased infections with omidubicel compared with UCB allogeneic transplantation. We report results of an Expanded Access Program evaluating clinical outcomes in patients with hematologic malignancies following transplantation with omidubicel. Between August 2020 and May 2023, 29 patients were transplanted at 5 US sites. Patients received myeloablative conditioning, prophylactic and therapeutic medications, and supportive care per institutional guidelines, and were monitored for engraftment, infections, and graft-versus-host-disease (GVHD) for up to 2 years post-transplant. Results were compared with previously reported phase 3 outcomes. Omidubicel recipients had a median age of 39 (range 20-73, 62% male); 45% were non-White and 65.5% had acute leukemia. Median follow-up was 11.8 (range: .3-27.7) months. Median neutrophil and platelet engraftment times were 12 and 33.5 days, respectively. Acute GVHD (grade 3-4) at day 100 occurred in 19% of patients, with chronic GVHD at 1 year in 9% of patients, all of which were mild. First grade 2 to 3 bacterial infections through 100 days post-transplant and first grade 3 viral infection 1 year post-transplant occurred in 18% and 12% of patients, respectively. One-year disease-free survival and overall survival rates were 76% and 87%, respectively. This real-world study of omidubicel transplantation for hematologic malignancies finds that this graft source is commonly used for non-White allogeneic transplant recipients. The rapid engraftment kinetics observed following transplantation with omidubicel appears to have addressed excessive nonrelapse mortality that has been previously observed following myeloablative umbilical cord blood transplantation.