On Aug. 24, 2026, Johnson & Johnson announced the U.S. Food and Drug Administration (FDA) approval of IMAAVY^® (nipocalimab-aahu) for the treatment of warm autoimmune hemolytic anemia (wAIHA) – a rare, life-threatening autoantibody disease – in adults and pediatric patients 12 years of age and older currently or previously treated with corticosteroids. The approval, which follows FDA Priority Review, marks the first time a therapy was proven safe and effective specifically for the treatment of wAIHA.

In wAIHA, pathogenic immunoglobulin G (IgG) autoantibodies attach to and destroy red blood cells, causing severe anemia, profound fatigue, and a significantly increased risk of morbidity and mortality. Previously, available treatment options only included corticosteroids and immunosuppressants — therapies that suppress the entire immune system without specifically targeting the IgG autoantibodies driving the disease.

The primary endpoint of the Phase 2/3 ENERGY study was durable hemoglobin (Hgb) response, a stringent endpoint definition that reflects meaningful increases in Hgb levels over time. The randomized, placebo-controlled trial demonstrated approximately three times as many patients receiving the approved dose of IMAAVY achieved durable Hgb levels versus placebo by 24 weeks. Overall patients in this treatment group showed a mean increase in Hgb of 1g/dL at Week 1. In addition, IMAAVY was associated with a 3.5-point higher mean FACIT-Fatigue^c score versus placebo at Week 24, with higher scores defined as less fatigue. In the ENERGY study IMAAVY demonstrated a safety profile consistent with the established safety profile of IMAAVY in generalized myasthenia gravis (gMG). The most common adverse reactions (≥10%) in patients with wAIHA treated with IMAAVY were peripheral edema, diarrhea, and fever.

“Today’s announcement marks the second approval for IMAAVY and is an extraordinary milestone for people living with warm autoimmune hemolytic anemia, an underserved community that has waited far too long for an FDA-approved treatment,” said David M. Lee, M.D., Ph.D., Global Immunology Therapeutic Area Head, Johnson & Johnson. “As the first therapy approved for wAIHA, IMAAVY has the potential to redefine the management of wAIHA, particularly for those with uncontrolled disease. This milestone reinforces our motivation to continue pursuing advanced therapies for people living with allo- and autoantibody diseases like wAIHA.”

IMAAVY was approved in the United States in April 2025 for the treatment of gMG in adult and pediatric patients 12 years of age and older who are acetylcholine receptor (AChR) or muscle-specific kinase (MuSK) antibody positive.