The US Food and Drug Administration (FDA) has approved Imaavy (nipocalimab) for the treatment of patients ages 12 years and older with warm autoimmune hemolytic anemia (wAIHA) who are currently or previously treated with corticosteroids.
wAIHA is a rare hematologic autoimmune condition characterized by antibodies that attack red blood cells and lead to hemolytic anemia. Symptoms may include unusual weakness and fatigue with tachycardia and breathing difficulties, jaundice, dark urine and/or splenomegaly. The cause of wAIHA is unknown.
The approval, which had an FDA Priority Review, is based on results from the phase 2/3 ENERGY clinical trial (NCT04119050). A total of 115 patients were randomized in this multicenter, double-blind, placebo-controlled study evaluating the efficacy and safety of nipocalimab compared with placebo. The primary endpoint was durable hemoglobin (Hgb) response.
Results from the study demonstrated that approximately three times as many patients receiving the approved dose of nipocalimab achieved durable Hgb levels versus placebo by 24 weeks. The efficacy of the treatment was quite rapid; nipocalimab-treated patients showed a mean increase in Hgb of 1g/dL at week 1 compared to no increase in the placebo-treated patients. In addition, nipocalimab was associated with a 3.5-point higher mean FACIT-Fatigue score versus placebo at week 24.
Nipocalimab demonstrated a safety profile consistent with the established safety profile in generalized myasthenia gravis. The most common adverse events in patients with wAIHA treated with nipocalimab were peripheral edema, diarrhea, and fever.
The full results of the ENERGY study were presented at the European Hematology Association 2026 meeting in June 2026.
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To learn more about wAIHA and other rare autoimmune conditions, visit https://checkrare.com/diseases/autoimmune-and-auto-inflammatory-disorders/