FDA Alert

FDA Approves First Treatment for Warm Autoimmune Hemolytic Anemia

Edited by:
Anthony Calabro, MA

Key Highlights

  • The FDA approved Imaavy (nipocalimab-aahu) for patients aged 12 years and older with warm autoimmune hemolytic anemia (wAIHA) who are currently or were previously treated with corticosteroids.
  • In a 24-week randomized trial, 24% of patients receiving nipocalimab-aahu 30 mg/kg achieved a durable hemoglobin response, compared with 8% receiving placebo.
  • The most common adverse reactions were peripheral edema, diarrhea, and fever.
  • Nipocalimab-aahu is the first FDA-approved treatment for wAIHA.

On August 25, the FDA approved nipocalimab-aahu (Imaavy, Janssen Biotech, Inc) injection for the treatment of warm autoimmune hemolytic anemia (wAIHA) in adults and pediatric patients aged 12 years and older who are currently or were previously treated with corticosteroids. In wAIHA, immunoglobulin G antibodies target red blood cells for destruction, resulting in hemolysis and anemia. The disorder affects approximately 1 to 3 people per 100,000 annually and is the most common type of autoimmune hemolytic anemia.

The approval was based on results from the 24-week, randomized, double-blind, placebo-controlled wAIHA Study (NCT04119050). The trial enrolled 118 patients with a confirmed diagnosis of wAIHA for at least 3 months, hemoglobin levels below 10 g/dL, evidence of active hemolysis, and a positive direct antiglobulin test. Participants received intravenous nipocalimab-aahu at 30 mg/kg every 4 weeks, 15 mg/kg every 2 weeks, or placebo. Patients could remain on stable doses of other medications used to treat wAIHA.

A durable hemoglobin response occurred in 24% of patients receiving nipocalimab-aahu 30 mg/kg compared with 8% receiving placebo. The 15-mg/kg regimen did not result in a higher proportion of patients achieving a durable hemoglobin response compared with placebo.

The most common adverse reactions among patients treated with nipocalimab-aahu were peripheral edema, diarrhea, and fever. Other reported side effects included infusion-related reactions such as headache, fatigue, influenza-like illness, rash, nausea, dizziness, chills, and erythema.

The FDA granted nipocalimab-aahu fast track, priority review, and orphan designations for this indication.

Reference
US Food and Drug Administration. FDA approves first drug for warm autoimmune hemolytic anemia. Accessed August 26, 2026. https://www.fda.gov/drugs/news-events-human-drugs/fda-approves-first-drug-warm-autoimmune-hemolytic-anemia