February 24, 2026 – Spring House, Pennsylvania, USA
Johnson & Johnson has announced the submission of a supplemental Biologics License Application (sBLA) to the U.S. Food and Drug Administration (FDA) seeking approval of IMAAVY® (nipocalimab-aahu) as the first-ever FDA-approved therapy for warm autoimmune hemolytic anemia (wAIHA). The rare and potentially life-threatening autoimmune condition affects approximately 1 in 8,000 individuals in the United States and currently has no approved treatment options. wAIHA occurs when pathogenic immunoglobulin G (IgG) autoantibodies bind to and destroy red blood cells, resulting in severe anemia, chronic fatigue, transfusion dependence, and increased risk of organ complications. Mortality rates among patients with wAIHA have been reported to be significantly higher than the general population, underscoring the urgent unmet medical need.
ENERGY Trial Demonstrates Durable Hemoglobin Response
The regulatory submission is supported by data from the pivotal Phase 2/3 ENERGY trial, a randomized, double-blind, placebo-controlled study evaluating nipocalimab in adults with wAIHA. Results demonstrated that a significantly higher proportion of patients receiving IMAAVY® achieved a durable hemoglobin response, defined as hemoglobin levels of at least 10 g/dL with an increase of ≥2 g/dL sustained for 28 days or longer without rescue therapy. In addition to hematologic improvement, treated patients experienced rapid and sustained reductions in disease-related fatigue, measured through validated clinical assessment tools.
The therapy was generally well tolerated, with a safety profile consistent with previous clinical experience. No new safety signals were identified. These findings reinforce the therapeutic potential of FcRn inhibition as a targeted strategy in IgG-mediated autoimmune diseases.
Targeting the Underlying Cause of wAIHA
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IMAAVY® is designed to selectively block the neonatal Fc receptor (FcRn), a key regulator responsible for recycling circulating IgG antibodies. By inhibiting FcRn, nipocalimab reduces levels of pathogenic IgG autoantibodies that drive red blood cell destruction while preserving essential immune functions, including components of humoral immunity. This immunoselective mechanism of action directly addresses the underlying pathophysiology of wAIHA rather than broadly suppressing the immune system.
Currently, management of wAIHA relies on off-label use of corticosteroids, immunosuppressants, and B-cell–directed therapies, which can carry significant long-term safety risks and variable response durability. If approved, IMAAVY® would represent the first targeted biologic therapy specifically indicated for this condition.
IMAAVY® previously received U.S. approval in April 2025 for the treatment of generalized myasthenia gravis (gMG) in patients aged 12 years and older who are antibody positive for acetylcholine receptor or muscle-specific kinase. The molecule has also received multiple regulatory designations, including Fast Track, Orphan Drug, and Breakthrough Therapy status across various autoimmune and maternal-fetal indications, reflecting its broader development potential within the autoantibody disease space.
The submission marks a significant milestone in expanding FcRn-targeted biologics into rare hematologic disorders. Regulatory review of the sBLA will determine whether IMAAVY® can become the first approved therapy specifically addressing the underlying immune mechanism of wAIHA, potentially transforming the treatment landscape for patients living with this serious autoimmune anemia.
Source: Johnson & Johnson press release
