FDA approved Imaavy (nipocalimab-aahu) for the treatment of warm autoimmune hemolytic anemia in adults and pediatric patients 12 years of age and older who are currently or previously treated with corticosteroids.

The approval marks the first time a therapy has been proven safe and effective for the treatment of warm autoimmune hemolytic anemia (wAIHA), a rare, life-threatening autoantibody disease.¹ The decision follows a Priority Review from FDA and represents the second approved indication for Imaavy.¹

The approval addresses a condition that has gone without a dedicated FDA-approved therapy despite the severity of its effects on patients. In warm autoimmune hemolytic anemia, pathogenic immunoglobulin G autoantibodies attach to and destroy red blood cells, causing severe anemia, profound fatigue, and a significantly increased risk of morbidity and mortality.¹

Until now, available treatment options were limited to corticosteroids and immunosuppressants, therapies that suppress the entire immune system rather than specifically targeting the IgG autoantibodies that drive the disease.

David Jimenez, president of Janssen Immunology, spoke with Pharmaceutical Executive about the importance of advancing and developing treatments for under-treated or hard to treat diseases, saying, “Immune-mediated diseases are chronic and often debilitating, with millions in the U.S. going undiagnosed, untreated, or under-treated."

What is the approval based on?

The approval is supported by the Phase II/III Energy study, a randomized, placebo-controlled trial whose primary endpoint was durable hemoglobin response, a stringent endpoint definition reflecting meaningful increases in hemoglobin levels over time.² Approximately three times as many patients receiving the approved dose of Imaavy achieved durable hemoglobin levels compared with placebo by 24 weeks. Patients in the treatment group also showed a mean increase in hemoglobin of 1 g/dL at week one. Imaavy was associated with a 3.5-point higher mean FACIT-Fatigue score compared with placebo at week 24, with higher scores indicating less fatigue.²

In the Energy study, Imaavy demonstrated a safety profile consistent with its established safety profile in generalized myasthenia gravis. The most common adverse reactions occurring in at least 10% of patients with warm autoimmune hemolytic anemia treated with Imaavy were peripheral edema, diarrhea, and fever, with full results of the Energy study being presented at the European Hematology Association 2026 meeting back in June 2026.²

Why does this approval matter for patients?

For patients living with warm autoimmune hemolytic anemia, the day-to-day reality has long been defined by unpredictability. "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. "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."

The clinical rationale behind the shift centers on targeting the underlying autoantibodies rather than broadly suppressing the immune system. "The Phase II/III Energy study demonstrates that targeting pathogenic IgG can meaningfully change the treatment paradigm for wAIHA," said David Kuter, M.D., D.Phil., distinguished physician, Massachusetts General Hospital and professor of medicine at Harvard Medical School. "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."

What's next for Imaavy?

Johnson & Johnson frames the approval as an extension of its broader strategy in autoantibody-driven disease. "Today's announcement marks the second approval for Imaavy and is an extraordinary milestone for people living with warm autoimmune hemolytic anemia, an underserved community that has waited far too long for an FDA-approved treatment," said David M. Lee, M.D., Ph.D., global immunology therapeutic area head, Johnson & Johnson. "As the first therapy approved for wAIHA, Imaavy has the potential to redefine the management of wAIHA, particularly for those with uncontrolled disease. This milestone reinforces our motivation to continue pursuing advanced therapies for people living with allo- and autoantibody diseases like wAIHA."

Imaavy was first approved in the U.S. back in April 2025 for the treatment of generalized myasthenia gravis in adult and pediatric patients 12 years of age and older who are acetylcholine receptor or muscle-specific kinase antibody positive.¹ With this second approval, Johnson & Johnson continues to build out its immunology portfolio around therapies that target IgG autoantibodies across multiple autoimmune conditions, rather than relying solely on broad immunosuppression.

Sources

1. FDA approves Imaavy (nipocalimab-aahu) as first-ever treatment for warm autoimmune hemolytic anemia (wAIHA), representing a landmark advancement for patients Johnson & Johnson August 24, 2026, https://www.prnewswire.com/news-releases/fda-approves-imaavy-nipocalimab-aahu-as-first-ever-treatment-for-warm-autoimmune-hemolytic-anemia-waiha-representing-a-landmark-advancement-for-patients-302858778.html
2. Imaavy (nipocalimab-aahu) demonstrates durable hemoglobin response and rapid onset of effect in pivotal Phase 2/3 study in warm autoimmune hemolytic anemia (wAIHA), an autoantibody-driven disease with no FDA-approved therapies Johnson & Johnson June 11, 2026, https://www.jnj.com/media-center/press-releases/imaavy-nipocalimab-aahu-demonstrates-durable-hemoglobin-response-and-rapid-onset-of-effect-in-pivotal-phase-2-3-study-in-warm-autoimmune-hemolytic-anemia-waiha-an-autoantibody-driven-disease-with-no-fda-approved-therapies