FDA Approves Nipocalimab-aahu as First Treatment for wAIHA

The FDA has approved nipocalimab-aahu (IMAAVY; Johnson & Johnson) for the treatment of warm autoimmune hemolytic anemia (wAIHA) in adults and children 12 years and older who are currently or previously treated with corticosteroids.¹ The approval, which followed FDA Priority Review, makes IMAAVY the first FDA-approved treatment specifically indicated for wAIHA.

“Living with wAIHA often means relentless fatigue and the constant uncertainty of not knowing what tomorrow will bring,” said Karen Jones, president and executive director, wAIHA Warriors, in a statement. “Patients may cycle through periods where they start to feel like themselves again—and then their hemoglobin drops, the exhaustion returns, and they’re back to square one. For the first time, our community has a treatment specifically for our disease.”

A Rare, High-Morbidity Disease With No Previously Approved Treatment

wAIHA is a rare, potentially life-threatening autoimmune disease in which pathogenic IgG autoantibodies target red blood cells, leading to hemolysis and anemia. Johnson & Johnson estimates that approximately 1 to 3 new cases occur per 100,000 people annually and that about 1 in 8000 people are living with the condition. Incidence increases with age, particularly after age 50. Patients may experience debilitating fatigue and are at increased risk of complications including venous thrombotic events, acute renal failure, and infection.

Before nipaclaimab-aahu’s approval, there were no FDA-approved drugs specifically indicated for wAIHA. Treatment generally relied on corticosteroids, immunosuppressive therapies, and B-cell–directed treatments used outside an FDA-approved wAIHA indication.

ENERGY Trial Demonstrated Durable Hemoglobin Responses

The approval is based on the phase 2/3 ENERGY study (NCT04119050), a multicenter, randomized, double-blind, placebo-controlled trial that enrolled 115 adults with wAIHA. Patients were randomized approximately 1:1:1 to receive nipocalimab at 30 mg/kg intravenously every 4 weeks, 15 mg/kg every 2 weeks, or placebo for 24 weeks, followed by an open-label extension.

The primary end point was durable hemoglobin response, defined as a hemoglobin concentration of at least 10 g/dL and an increase from baseline of at least 2 g/dL maintained for at least 28 days, without the need for rescue therapy. In the approved 30-mg/kg every-4-week group, 23.7% of patients achieved a durable hemoglobin response compared with 7.7% of patients receiving placebo (P = .015). The 15-mg/kg every-2-week group had a 21.1% response rate, but that comparison did not meet the prespecified threshold for statistical significance.

Patients receiving the approved regimen had a mean hemoglobin increase of approximately 1 g/dL by week 1. This analysis was not part of the hierarchical statistical testing procedure and should therefore be considered descriptive.

Fatigue also improved with treatment. At week 24, the mean FACIT-Fatigue score increased by 3.4 points from baseline with 30 mg/kg every 4 weeks compared with 0.6 points with placebo, corresponding to a between-group difference of approximately 3.5 points. Johnson & Johnson characterized this as a key secondary end point, but the result was considered nominal under the prespecified statistical analysis plan.

The safety findings were consistent with the established safety profile of nipocalimab-aahu, with no new safety signals identified. Peripheral edema, diarrhea, and fever were among the most common adverse reactions in patients with wAIHA.

“The phase 2/3 ENERGY study demonstrates that targeting pathogenic IgG can meaningfully change the treatment paradigm for wAIHA,” said David Kuter, MD, DPhil, distinguished physician, Massachusetts General Hospital, and professor of medicine at Harvard Medical School, in a statement. “More patients treated with IMAAVY achieved a durable hemoglobin response compared with placebo—meaning their red blood cell levels went up and stayed up. For patients, this approval means that they now have a therapy with a proven safety profile that targets the disease-driving autoantibodies in wAIHA.”

Nipocalimab-aahu was previously approved in April 2025 for generalized myasthenia gravis in adults and pediatric patients 12 years and older who are AChR- or MuSK-antibody positive.²

Johnson & Johnson also offers the IMAAVY withMe patient support program, which includes educational resources, a dedicated nurse navigator, and cost-support options.¹

References

1. FDA approves IMAAVY (nipocalimab-aahu) as first-ever treatment for warm autoimmune hemolytic anemia (wAIHA), representing a landmark advancement for patients. Johnson & Johnson. News release. August 24, 2026. Accessed August 25, 2026. https://www.jnj.com/media-center/press-releases/fda-approves-imaavy-nipocalimab-aahu-as-first-ever-treatment-for-warm-autoimmune-hemolytic-anemia-waiha-representing-a-landmark-advancement-for-patients
2. Mattina C. FDA approves nipocalimab for generalized myasthenia gravis. AJMC^®. April 30, 2025. Accessed August 25, 2026. https://www.ajmc.com/view/fda-approves-nipocalimab-for-generalized-myasthenia-gravis