FDA Approves First Stem Cell Therapy for Severe Aplastic Anemia
WASHINGTON, D.C. — The U.S. Food and Drug Administration has taken a landmark step in treating severe aplastic anemia (SAA) by approving the first hematopoietic stem cell transplant therapy specifically designed for this rare and life-threatening disorder. The newly authorized treatment, Omisirge, developed by Gamida Cell Inc., represents a significant advance in regenerative medicine and offers a novel option for patients six years and older who have limited alternatives.
Severe aplastic anemia occurs when the bone marrow fails to produce adequate numbers of red blood cells, white blood cells, and platelets, leaving patients vulnerable to fatigue, infections, and bleeding. The disease often results from the immune system attacking the marrow’s blood-forming cells. Traditional treatment options include stem cell transplants from matched sibling donors or umbilical cord blood, but donor availability and complications such as delayed recovery and graft-versus-host disease have limited their effectiveness.
Omisirge is a stem cell therapy derived from umbilical cord blood that has been chemically enhanced with nicotinamide, a form of vitamin B3, to improve the engraftment and function of transplanted cells. This enhancement accelerates the restoration of the patient’s blood and immune system, reducing the time to neutrophil recovery and potentially lowering infection risks. The therapy is administered after a reduced-intensity conditioning regimen, making it suitable for a broader patient population.
Clinical data presented at the 2025 American Society of Hematology Annual Meeting demonstrated promising results. In a study led by Dr. Richard Childs of the National Heart, Lung, and Blood Institute at the National Institutes of Health, 14 high-risk patients with SAA who were unresponsive to other treatments showed significantly better outcomes than expected. Twelve patients achieved rapid neutrophil recovery with a median time of just 11 days. Moreover, only 16% experienced mild acute graft-versus-host disease, and no cases of severe or chronic GVHD were reported. The overall survival rate was 94%, with 86% becoming independent of red blood cell transfusions.
“The approval of Omisirge is a significant step forward in the treatment options available for patients with a high unmet medical need,” Dr. Childs said. “Patients in the study demonstrated remarkably fast and high rates of neutrophil engraftment, leading to a rapid return to normal life.”
Dr. Vinay Prasad, chief medical and scientific officer at the FDA’s Center for Biologics Evaluation and Research, described the approval as “revolutionary,” emphasizing that it fundamentally changes the therapeutic landscape for SAA. “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,” he said.
Omisirge’s wholesale cost is approximately $338,000 for a single treatment course, excluding transplant procedure and hospitalization expenses. Production is slated to begin within two years at a manufacturing facility in Hopkinton, Massachusetts. By 2027, the therapy could treat between 2,000 and 2,500 patients annually in the United States.
The therapy’s approval builds on Gamida Cell’s earlier FDA authorization in 2023 for hematological malignancies in patients 12 and older, marking a growing recognition of enhanced cord blood stem cell therapies in hematology.
For patients and families affected by severe aplastic anemia, this advancement offers renewed hope. As Dr. Megha Kaushal, acting deputy director of the FDA’s Office of Therapeutic Products, noted, “Omisirge will shorten time to neutrophil recovery, which leads to shorter recovery times after transplant and may improve infection rates in this patient population.”
Severe aplastic anemia remains a challenging condition to treat, with limited curative options. The FDA’s approval of Omisirge underscores ongoing efforts to harness innovative cell therapies to improve patient outcomes.
More information on aplastic anemia and stem cell transplantation can be found through the U.S. Food and Drug Administration, the National Heart, Lung, and Blood Institute, and the Centers for Disease Control and Prevention. Details on stem cell therapies are also available from the National Institutes of Health Stem Cell Information portal.
Leave a Reply