The U.S. Food and Drug Administration today announced it has approved Omisirge (omidubicel-onlv), the first hematopoietic stem cell transplant (HSCT) therapy to treat patients with severe aplastic anemia (SAA). Omisirge is indicated for adults and pediatric patients 12 years and older with hematologic malignancies and now is approved for adults and pediatric patients six years and older with SAA following reduced intensity conditioning and for whom a compatible donor is not available.

“This approval is revolutionary in the therapeutic landscape and fundamentally changes how we approach treatment for SAA, where earlier treatment has potential to alter one’s life course,” Vinay Prasad, M.D., M.P.H., Chief Medical and Scientific Officer and Director of the FDA’s Center for Biologics Evaluation and Research. “Severe aplastic anemia is a rare blood disorder that can be fatal, and the FDA remains committed to expanding treatment options for patients with this disease.”

SAA is a rare, life-threatening blood disorder where the bone marrow fails to produce enough red blood cells, white blood cells and platelets. Treatment for SAA depends on age and usually consists of either immunosuppressive therapy and/or hematopoietic stem cell transplant preferably from a matched sibling or matched related donor. If a donor is not available, providers may seek the use of umbilical cord transplant to treat SAA. Umbilical cord transplant typically has limitations of use including delayed hematopoietic recovery and increased risks of infections. Omisirge is a stem cell therapy where donated cord blood stem cells have been chemically enhanced with nicotinamide (a form of vitamin B3) and then given to a patient to help restore their blood and immune system.

Omisirge addresses the limitations of umbilical cord blood (UCB) as a source including delayed hematopoietic recovery and increased infections and provides additional graft options for patients with severe aplastic anemia (SAA) who need hematopoietic stem cell transplant (HSCT).

“Omisirge is a novel stem cell product from umbilical cord blood that will be able to offer a therapeutic option for patients with severe aplastic anemia who have limited options for stem cell transplant,” said Megha Kaushal M.D., M.S., Acting Deputy Director of the CBER Office of Therapeutic Products and pediatric hematologist. “Omisirge will shorten time to neutrophil recovery which leads to shorter recovery times after transplant and may improve infection rates in this patient population.”

The safety and effectiveness of Omisirge was assessed based on an ongoing, open-label, prospective, single arm study evaluating use of Omisirge in patients six years and older with severe aplastic anemia. Omisirge provided early and sustained neutrophil engraftment in 12 of 14 patients in the efficacy population with a median time to neutrophil recovery of 11 days (range seven to 20 days).

The most common side effects associated with Omisirge include febrile neutropenia, viral and bacterial infections, hyperglycemia, immune thrombocytopenia and pneumonia. Autoimmune cytopenias have occurred in 25% of patients.

The application was granted Orphan Drug and Priority Review designations.

The FDA granted approval of Omisirge to Gamida Cell Ltd.

Source:

U.S. Food and Drug Administration. FDA Approves First Cellular Therapy to Treat Patients with Severe Aplastic Anemia [Internet]. Silver Spring (MD): FDA; 2025 Dec 8 [cited 2025 Dec 11]. Available from: https://www.fda.gov/news-events/press-announcements/fda-approves-first-cellular-therapy-treat-patients-severe-aplastic-anemia fda.gov

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