The US Food and Drug Administration (FDA) has expanded the label indication of Johnson & Johnson’s (J&J) Imaavy (nipocalimab-aahu) to treat a rare blood disorder, boosting the drug’s blockbuster credentials.
Imaavy is now approved to treat warm autoimmune haemolytic anaemia (wAIHA) – a rare and sometimes life-threatening autoantibody disease – in adults and paediatric patients 12 years of age and older currently or previously treated with corticosteroids. Following the regulatory update, J&J’s drug is the first and only approved medicine in the US specifically for treating the disease.
The approval marks an expansion to Imaavy’s label, which was first authorised by the FDA to treat generalised myasthenia gravis in certain adults and patients aged 12 and older in April 2025.
The FDA based its wAIHA decision on data from the Phase II/III ENERGY study (NCT04119050), data from which J&J presented in June this year. Imaavy demonstrated a strong ability to elicit a durable red blood-cell count in patients with the disorder compared to placebo after 24 weeks – meeting the trial’s primary endpoint.
Patients with wAIHA typically have a low red blood-cell count and low haemoglobin levels due to the immune system mistakenly attacking and destroying red blood cells. Approximately 1-3 new people per 100,000 are affected by wAIHA per year, and about one in 8,000 individuals are living with the condition, according to J&J.
Imaavy is an immunoselective treatment designed to block the neonatal Fc receptor (FcRn), reducing circulating immunoglobulin G (IgG) antibodies that drive disease while also preserving B-cell function.
Karen Jones, president of non-profit wAIHA Warriors, said: “Living with wAIHA often means relentless fatigue and the constant uncertainty of not knowing what tomorrow will bring. Patients may cycle through periods where they start to feel like themselves again — and then their haemoglobin drops, the exhaustion returns, and they’re back to square one. For the first time, our community has a treatment specifically for our disease.”
For J&J, the expansion marks another validation of its strategy to obtain the drug in its $6.5bn acquisition of Momenta Pharmaceuticals in 2020. Generalised myasthenia gravis is already a sizeable market and wAIHA adds another revenue stream for Imaavy. J&J has ascribed a $5bn peak sales target for Imaavy, reflecting its high hopes for the antibody. The pharma company is also evaluating it as a treatment in other autoimmune disorders, including Sjogren’s disease, systemic lupus erythematosus, and haemolytic disease of the foetus and newborn, among others.
