FDA Approves Omidubicel for Adult and Pediatric Patients With Severe Aplastic Anemia

The FDA has approved omidubicel-onlv (Omisirge) for adults and pediatric patients 6 years or older with severe aplastic anemia (SAA) following reduced-intensity conditioning and for whom a compatible donor is not available, making it the first hematopoietic stem cell transplant (HSCT) therapy approved to treat patients with this condition.1

Of note, the agent was previously approved by the FDA in April 2023 for use in adults and pediatric patients 12 years and older with hematologic malignancies who are planned for UCB transplantation following myeloablative conditioning to reduce the time to neutrophil recovery and the incidence of infection.2

Findings from an ongoing, open-label, prospective, single-arm phase 1/2 study (NCT03173937) of patients between 4 to 75 years of age with SAA supported this regulatory decision.1,3 Results showed early and sustained neutrophil engraftment with the agent among 12 patients in the efficacy population (n = 14).1 The median time to neutrophil recovery was 11 days (range, 7-20).

Regarding safety, the most common adverse effects observed with omidubicel include febrile neutropenia, viral and bacterial infections, hyperglycemia, immune thrombocytopenia, and pneumonia. Autoimmune cytopenias have occurred in 25% of patients.

“This approval is revolutionary in the therapeutic landscape and fundamentally changes how we approach treatment for SAA, where earlier treatment has [the] potential to alter one’s life course,” Vinay Prasad, MD, MPH, chief medical and scientific officer and director of the FDA’s Center for Biologics Evaluation and Research, stated in a news release. “SAA is a rare blood disorder that can be fatal, and the FDA remains committed to expanding treatment options for patients with this disease.”

What is the mechanism of action of omidubicel?

Omidubicel is an allogeneic stem cell product in which donated UCB stem cells are expanded and chemically modified with nicotinamide, a form of vitamin B3, to support hematopoietic and immune reconstitution following transplantation. The therapy is designed to mitigate key limitations associated with traditional UCB grafts, including delayed hematopoietic recovery and increased infection risk, and offers an additional donor source for patients with SAA who require HSCT.

“[Omibudicel] is a novel stem cell product from umbilical cord blood that will be able to offer a therapeutic option for patients with SAA who have limited options for stem cell transplant,” Megha Kaushal MD, MS, acting deputy director of the CBER Office of Therapeutic Products and a pediatric hematologist, added. “Omisirge will shorten time to neutrophil recovery which leads to shorter recovery times after transplant and may improve infection rates in this patient population.”

What additional data with omidubicel have been reported?

Interim results from the phase 1/2 study were recently presented at the 2025 ASH Annual Meeting.4 The aim of this study is to evaluate whether treating people with SAA or myelodysplastic syndrome with a co-infusion of blood stem cells from a family member and cord blood stem cells from an unrelated donor is safe and effective.3

Among 19 patients whose disease had not responded to standard therapies, 95% achieved rapid neutrophil recovery, with a median time of 8 days.4 Disease-free and overall survival rates were 94%. Moreover, the incidence of graft-versus-host disease (GVHD) was low; 16% of patients experienced grade 2 acute GVHD, and no cases of severe or chronic GVHD were reported.

References

1. FDA approves first cellular therapy to treat patients with severe aplastic anemia. FDA. December 8, 2025. Accessed December 9, 2025. https://www.fda.gov/news-events/press-announcements/fda-approves-first-cellular-therapy-treat-patients-severe-aplastic-anemia
2. FDA approves cell therapy for patients with blood cancers to reduce risk of infection following stem cell transplantation. FDA. April 17, 2023. Accessed December 9, 2025. https://www.fda.gov/news-events/press-announcements/fda-approves-cell-therapy-patients-blood-cancers-reduce-risk-infection-following-stem-cell
3. Unrelated umbilical cord blood transplantation for severe aplastic anemia and hypoplastic MDS using CordIn(TM), umbilical cord blood-derived ex vivo expanded stem and progenitor cells to expedite engraftment and improve transplant outcomes. ClinicalTrials.gov. Updated November 25, 2025. Accessed December 9, 2025. https://clinicaltrials.gov/study/NCT03173937
4. Additional positive results for Omidubicel in treating severe aplastic anemia presented at ASH. Gamida Cell. News release. December 8, 2025. Accessed December 9, 2025. https://www.gamida-cell.com/press_release/additional-positive-results-for-omidubicel-in-treating-severe-aplastic-anemia-presented-at-ash/