FDA grants Priority Review for IMAAVY (nipocalimab‑aahu) in warm autoimmune hemolytic anemia
IMAAVY is designed to target the underlying cause of warm autoimmune hemolytic anemia by reducing circulating immunoglobulin G, including autoantibodies, while preserving critical immune functions
27 Apr 2026
Johnson & Johnson announced that the U.S. Food and Drug Administration (FDA) has granted Priority Review to the supplemental Biologics License Application (sBLA) for IMAAVY® (nipocalimab-aahu),c confirming the urgent need for treatment options in warm autoimmune hemolytic anemia (wAIHA). Priority Review is granted to medicines that may offer significant improvements in safety or effectiveness for serious conditions and shortens the FDA review timeline to approximately six months.1 IMAAVY is the first therapy to receive FDA Priority Review for this condition.
"Warm autoimmune hemolytic anemia is a severe disease in which pathogenic immunoglobulin G (IgG) antibodies, also called autoantibodies, drive destruction of red blood cells. Currently, patients depend on broad immunosuppressive therapies that fail to address the underlying cause of disease and are not approved as safe or effective to treat wAIHA," said Leonard L. Dragone, M.D., Ph.D., Disease Area Leader, Autoantibody and Rheumatology, Johnson & Johnson. "This designation highlights both the serious, life-threatening nature of wAIHA and the potential for IMAAVY, if approved, to help address a critical unmet need by delivering clinically meaningful outcomes for patients."
IMAAVY is designed to block the neonatal Fc receptor (FcRn), reducing circulating IgG, including pathogenic autoantibodies, while preserving key immune functions.2,3 By targeting the underlying driver of disease, IMAAVY utilizes a differentiated immunoselective approach in a condition where many patients currently rely on therapies that are unapproved for wAIHA, including corticosteroids and broad immunosuppressants.4
The FDA's decision to grant Priority Review is supported by results from the pivotal Phase 2/3 ENERGY study, which showed that more patients treated with IMAAVY achieved a durable hemoglobin responsea compared with placebo, along with improvements in fatigue,b a critical outcome for people living with wAIHA.5 The full results of the ENERGY trial will be presented at an upcoming medical conference.
Nipocalimab is being studied across multiple auto- and alloantibody-driven diseases as part of Johnson & Johnson's broader commitment to advancing transformational immunology therapies.
Editor's Notes:
a. Durable hemoglobin response = hemoglobin concentration ≥10 g/dL and an increase from baseline in hemoglobin ≥2 g/dL for at least 28 days
b. As measured by Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue) Scale
c. IMAAVY is not approved by the U.S. FDA for the treatment of wAIHA
References:
1. U.S. Food & Drug Administration. Priority review. Available at: https://www.fda.gov/patients/fast-track-breakthrough-therapy-accelerated-approval-priority-review/priority-review. Accessed April 2026.
2. Ling LE, et al. M281, an anti‑FcRn antibody: pharmacodynamics, pharmacokinetics, and safety across the full range of IgG reduction in a first‑in‑human study. Clinical Pharmacology & Therapeutics. 2018;105(4):1031–1039. doi:10.1002/cpt.1276.
3. Cossu M, et al. A randomized, open‑label study on the effect of nipocalimab on vaccine response in healthy participants. Presented at: American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) Annual Meeting; October 2024.
4. Sudulagunta SR, et al. Warm autoimmune hemolytic anemia: clinical profile and management. Journal of Hematology. 2017;6(1):12–20. Published online March 21, 2017. doi:10.14740/jh303w.
5. ClinicalTrials.gov. NCT04119050. Available at: https://www.clinicaltrials.gov/study/NCT04119050. Accessed April 2026.