On Tuesday, the U.S. Food and Drug Administration (FDA) approved Johnson & Johnson's (JNJ  ) IMAAVY (nipocalimab-aahu) to treat warm autoimmune hemolytic anemia (wAIHA).

New Therapy for Rare Autoantibody Disease

The agency cleared the medication for adults and pediatric patients aged 12 and older who currently receive or previously received corticosteroids.

Following a Priority Review, IMAAVY stands as the very first therapy specifically proven safe and effective for this rare, life-threatening condition.

In patients suffering from wAIHA, pathogenic immunoglobulin G (IgG) autoantibodies attach to and destroy healthy red blood cells. This destructive process causes severe anemia, profound fatigue, and an elevated risk of morbidity and mortality.

Before this approval, standard treatments only included corticosteroids and generalized immunosuppressants.

Those traditional therapies suppress the entire immune system instead of precisely targeting the IgG autoantibodies driving the illness.

Clinical Trial Efficacy And Established Safety

The Phase 2/3 ENERGY study evaluated the drug's effectiveness, using durable hemoglobin (Hgb) response as the primary endpoint to measure meaningful increases over time.

The randomized, placebo-controlled trial revealed that approximately three times as many patients receiving the approved dose of IMAAVY achieved durable Hgb levels by 24 weeks compared to the placebo group.

Overall, patients taking the medication demonstrated a mean Hgb increase of 1g/dL at Week 1. Additionally, the drug helped reduce exhaustion, showing a 3.5-point higher mean FACIT-Fatigue score versus placebo at Week 24.

The FDA previously approved IMAAVY in April 2025 for generalized myasthenia gravis patients 12 years and older who are acetylcholine receptor or muscle-specific kinase antibody positive.

JNJ Price Action: Johnson & Johnson shares were down 0.33% at $270.81 during premarket trading on Tuesday. The stock is approaching its 52-week high of $276.47, according to Benzinga Pro data.