The US Food and Drug Administration has approved nipocalimab-aahu (IMAAVY) for adults and pediatric patients aged 12 years and older with warm autoimmune hemolytic anemia who are currently or were previously treated with corticosteroids, according to a press release from Johnson & Johnson. It is the first therapy approved specifically for the condition. Nipocalimab was previously approved in April 2025 for the treatment of generalized myasthenia gravis in adults and pediatric patients aged 12 years and older who are acetylcholine receptor or muscle-specific kinase antibody-positive.
Warm autoimmune hemolytic anemia (wAIHA) is a condition in which autoantibodies attach to and destroy red blood cells, resulting in anemia. Patients with wAIHA have an increased risk of complications including venous thrombotic events, acute renal failure, and infection.
Nipocalimab binds to and blocks the neonatal Fc receptor, reducing circulating immunoglobulin G antibodies while preserving B-cell function based on in vitro and/or in vivo studies.
The approval was based on findings from the phase 2/3 ENERGY trial, a multicenter, randomized, double-blind, placebo-controlled study that evaluated the efficacy and safety of nipocalimab compared with placebo in 115 adults with wAIHA. Participants were randomized approximately 1:1:1 across 2 nipocalimab dosing groups and a placebo group. Following 24 weeks of double-blind treatment, participants could enter a 144-week open-label extension followed by 6 weeks of follow-up.
The primary endpoint was durable hemoglobin response, defined as a hemoglobin concentration of at least 10 g/dL and an increase of at least 2 g/dL from baseline for at least 28 days, with the criteria met starting by week 16 of the double-blind period without rescue therapy. Approximately 3 times as many participants who received the approved nipocalimab dose achieved a durable hemoglobin response vs those who received placebo by week 24.
Participants who received the approved dose had a mean hemoglobin increase of 1 g/dL at week 1. At week 24, the mean change from baseline in Functional Assessment of Chronic Illness Therapy-Fatigue score was 3.5 points higher with nipocalimab vs placebo. Higher scores indicated less fatigue. The company characterized these findings as descriptive under the prespecified statistical analysis plan.
The most common adverse reactions, reported in at least 10% of patients with wAIHA treated with nipocalimab, were peripheral edema, diarrhea, and fever. The company’s safety information identifies infections, hypersensitivity reactions, and infusion-related reactions as potential adverse effects.
The approved dose is 30 mg/kg administered intravenously every 4 weeks.
Source: Johnson & Johnson
