SPRING HOUSE, Pa. — Johnson & Johnson submitted an application to the U.S. Food and Drug Administration on Tuesday, February 24, 2026, seeking approval for IMAAVY® (nipocalimab-aahu) as the first treatment for warm autoimmune hemolytic anemia (wAIHA), a rare and potentially life-threatening autoimmune disorder.
The supplemental Biologics License Application (sBLA) follows promising results from the Phase 2/3 ENERGY trial, which demonstrated that IMAAVY® led to a durable hemoglobin response in adults with wAIHA. According to Johnson & Johnson, a durable response was defined as achieving a hemoglobin level of 10 g/dL or higher, with an increase of at least 2 g/dL, sustained for at least 28 days without the demand for rescue therapy.
wAIHA affects approximately 1 in 8,000 people in the United States and occurs when the immune system mistakenly attacks red blood cells, leading to anemia. Patients often experience severe fatigue, require frequent blood transfusions, and are at risk of organ failure. Individuals with wAIHA face a 20-30% higher risk of death, according to Johnson & Johnson.
“People living with warm autoimmune hemolytic anemia face a serious, life-threatening disease with no approved treatment options and a high risk of complications,” said David M. Lee, M.D., Ph.D., Global Immunology Therapeutic Area Head at Johnson & Johnson. “The submission of this sBLA represents an important milestone for the wAIHA community and underscores our commitment to advancing targeted, immunoselective therapies that can deliver meaningful, rapid improvement for these patients.”
IMAAVY® works by selectively blocking the neonatal Fc receptor (FcRn), which regulates the recycling of IgG antibodies. By reducing circulating IgG, including the autoantibodies that destroy red blood cells, the drug aims to address the underlying cause of wAIHA although preserving some immune functions. The ENERGY trial also showed that patients treated with IMAAVY® experienced a rapid and sustained improvement in fatigue, as measured by the FACIT-Fatigue scale.
Bruno Fattizzo, M.D., Assistant Professor at the Department of Oncology and Hematology-Oncology, Università degli Studi di Milan, stated that the ENERGY study provided “a strong rationale for the potential of IMAAVY to rapidly improve fatigue and provide durable hemoglobin response while maintaining favorable tolerability.”
The FDA previously approved IMAAVY® in April 2025 for the treatment of generalized myasthenia gravis (gMG), another autoimmune disorder, in adults and children aged 12 and older. The Muscular Dystrophy Association applauded that approval, noting that IMAAVY® is the first FcRn blocker approved for gMG.
IMAAVY® was generally well-tolerated in the ENERGY trial, with no novel safety signals identified. Full results from the ENERGY trial are forthcoming. The drug has received Fast Track designation from the FDA for both wAIHA and hemolytic disease of the fetus and newborn, as well as Orphan Drug status for wAIHA.
Johnson & Johnson has also been granted FDA Breakthrough Therapy designation for IMAAVY® in fetal and neonatal alloimmune thrombocytopenia and Sjögren’s disease. The company is investigating nipocalimab across a range of autoimmune conditions, including rheumatologic diseases and maternal-fetal diseases.
