FDA Approves Omidubicel-onlv (Omisirge) As First Cellular Severe Aplastic Anemia Therapy

The US Food and Drug Administration (FDA) has approved Ayrmid’s omidubicel-onlv (Omisirge) for the treatment of severe aplastic anemia (SAA), making it the first hematopoietic stem cell transplant therapy for this indication.1,2

As described in a December 8, 2025, release from the FDA, with the approval, omidubicel-onlv is indicated for adults and pediatric patients ≥ 12 years of age with hematologic malignancies as well as adults and pediatric patients ≥ 6 years of age with SAA following reduced intensity conditioning and for whom a compatible donor is not available.2

“The approval of [omidubicel-onlv] is a significant step forward in the treatment options available for patients with a high unmet medical need,” Richard Childs, MD, of the National Heart, Lung, and Blood Institute at the National Institutes of Health, said in a statement.1 “Patients in the study with aplastic anemia were high risk, but had significantly better than expected outcomes and demonstrated remarkably fast and high rates of neutrophil engraftment. This was achieved with low rates of mild acute GVHD and no chronic GVHD meaning the patients achieved a rapid return to a normal life.”

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 consists of immunosuppressive therapy and/or hematopoietic stem cell transplant.

Omidubicel-onlv 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. It addresses the limitations of umbilical cord blood as a source including delayed hematopoietic recovery and increased infections and provides additional graft options for patients with SAA who need hematopoietic stem cell transplant.

“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, MD, MPH, Chief Medical and Scientific Officer and Director of the FDA’s Center for Biologics Evaluation and Research, said in a statement.2

The approval is based on results from an ongoing open-label, single-center study in patients 6 years and older with SAA showing a median time to neutrophil recovery of 11 days, 86% of patients experiencing early and sustained neutrophil recovery at 100 days, rapid immune recovery post-transplant, and 86% of patients achieving red blood cell transfusion independence. Additionally, no cases of BMT-CTN severe acute graft-versus-host disease (GVHD), or chronic GVHD occurred, and a 92% disease-free and overall survival rate was observed.1

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.2

“[Omidubicel-onlv] 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 MD, MS, Acting Deputy Director of the CBER Office of Therapeutic Products and pediatric hematologist.2 “[Omidubicel-onlv] will shorten time to neutrophil recovery which leads to shorter recovery times after transplant and may improve infection rates in this patient population.”

References

1. Ayrmid. FDA approves Omisirge® as First Approved Cell Therapy to Treat Severe Aplastic Anemia. December 8, 2025. Accessed December 8, 2025. https://www.gamida-cell.com/press_release/fda-approves-omisirge-as-first-approved-cell-therapy-to-treat-severe-aplastic-anemia/

2. FDA. FDA Approves First Cellular Therapy to Treat Patients with Severe Aplastic Anemia. December 8, 2025. Accessed December 8, 2025. https://www.fda.gov/news-events/press-announcements/fda-approves-first-cellular-therapy-treat-patients-severe-aplastic-anemia