Johnson & Johnson’s IMAAVY (nipocalimab‑aahu) improved hemoglobin, reduced fatigue, and lowered steroid use in the Phase 2/3 ENERGY trial for warm autoimmune hemolytic anemia (wAIHA), supporting FDA Priority Review in a disease with no approved therapies.
Written By: Shaik Yasmeen, PharmD
Reviewed By: Pharmacally Editorial Team
Johnson & Johnson presented new data from the Phase 2/3 ENERGY trial showing that IMAAVY® (nipocalimab-aahu) significantly improved hemoglobin levels in adults with warm autoimmune hemolytic anemia (wAIHA), a rare autoimmune blood disorder with no FDA-approved therapies. The findings were presented at the European Hematology Association (EHA) 2026 Congress and support the therapy’s ongoing regulatory review in the United States.
Patients receiving the FDA-submitted regimen of 30 mg/kg intravenously every four weeks achieved statistically significant durable hemoglobin responses compared with placebo. By Week 24, approximately three times as many patients treated with IMAAVY achieved a durable hemoglobin response versus placebo.
Targeting Autoantibody-Driven Disease
wAIHA occurs when IgG autoantibodies attack and destroy red blood cells, leading to chronic anemia, severe fatigue, and potentially life-threatening complications. Current treatment primarily relies on off-label corticosteroids and immunosuppressive therapies.
IMAAVY is a neonatal Fc receptor (FcRn) blocker that reduces circulating pathogenic IgG antibodies while preserving key immune functions. The therapy targets the autoantibodies responsible for red blood cell destruction, addressing the underlying disease process.
Rapid and Sustained Clinical Benefit
The multicenter, randomized, double-blind, placebo-controlled ENERGY study (NCT04119050) enrolled 115 adults with wAIHA who were randomized to receive one of two nipocalimab dosing regimens or placebo.
The primary endpoint required patients to achieve a hemoglobin increase of at least 2 g/dL from baseline and maintain hemoglobin levels of at least 10 g/dL for a minimum of 28 days beginning by Week 16, without rescue therapy or changes to background treatment.
Patients receiving the 30 mg/kg regimen demonstrated a rapid onset of effect, with mean hemoglobin levels increasing by 1 g/dL as early as Week 1, while placebo-treated patients showed no meaningful change. Nearly two-thirds of patients achieved both clinically meaningful hemoglobin targets by Week 24.
IMAAVY also improved patient-reported fatigue, with benefits emerging by Week 2 and persisting throughout the 24-week treatment period. In addition, patients achieving durable responses were able to reduce corticosteroid use, with a mean 15% reduction from baseline compared with 4% in the placebo group.
Safety Profile
IMAAVY demonstrated a safety profile consistent with its approved use in generalized myasthenia gravis. The most common adverse events were peripheral edema, diarrhea, and pyrexia, and investigators reported no new safety signals.
Clinical Implication
Bruno Fattizzo, M.D., Assistant Professor at the University of Milan, said the rapid correction of anemia observed in the study could have important clinical implications for patients living with wAIHA, particularly given the significant fatigue associated with the disease.
Leonard L. Dragone, M.D., Ph.D., Disease Area Leader for Autoantibody and Rheumatology at Johnson & Johnson, highlighted the significance of achieving durable hemoglobin improvements in the first large placebo-controlled trial conducted in this patient population while maintaining a consistent safety profile.
Regulatory Path
IMAAVY is already approved in the United States for generalized myasthenia gravis in anti-acetylcholine receptor (AChR)- or anti-muscle-specific tyrosine kinase (MuSK)-antibody-positive patients aged 12 years and older.
The new wAIHA data support the supplemental Biologics License Application (sBLA) currently under FDA Priority Review and position IMAAVY as a potential first approved treatment for the disease.
Beyond wAIHA, Johnson & Johnson continues to advance nipocalimab across multiple autoantibody-mediated conditions, including Sjögren’s disease, systemic lupus erythematosus, fetal and neonatal alloimmune thrombocytopenia, and hemolytic disease of the fetus and newborn.
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About the Writer
Shaik Yasmeen (LinkedIn) is a Pharm.D graduate with interests in clinical pharmacy, pharmacovigilance, and medical writing. She has gained experience through hospital clinical postings, patient case reviews, case presentations, and literature evaluation. Passionate about evidence-based healthcare, she is committed to creating accurate and engaging medical content while continuously expanding her professional knowledge.