SILVER SPRING, MARYLAND, Aug 26, 2026
The U.S. Food and Drug Administration (FDA) has approved Imaavy (nipocalimab-aahu) injection for the treatment of warm autoimmune hemolytic anemia (wAIHA) in adult and pediatric patients 12 years of age and older who are currently or previously treated with corticosteroids. Developed by Janssen Biotech, Inc., the approval establishes Imaavy as the first FDA-approved treatment for warm autoimmune hemolytic anemia, a rare and potentially serious blood disorder in which the immune system attacks and destroys the body’s own red blood cells. The regulatory decision addresses a significant unmet medical need for patients whose disease can cause persistent anemia and related complications.
Imaavy Becomes First Approved wAIHA Treatment
Warm autoimmune hemolytic anemia occurs when the immune system mistakenly identifies healthy red blood cells as targets for destruction. In wAIHA, immunoglobulin G (IgG) antibodies attach to red blood cells and promote their destruction by immune cells. The resulting hemolysis can occur faster than the body can replace red blood cells, causing anemia and reduced oxygen delivery to tissues. The condition is called “warm” because the antibody-mediated destruction occurs at normal body temperature. wAIHA is the most common form of autoimmune hemolytic anemia and affects approximately 1 to 3 people per 100,000 each year. It can occur across age groups and represents a serious clinical burden for affected patients. The FDA approval of Imaavy provides the first specifically approved drug therapy for this condition, potentially expanding treatment options for patients who have already received or are receiving corticosteroid therapy.
Phase 3-Style Trial Data Supported FDA Decision
The FDA based its approval on results from the wAIHA Study (NCT04119050), described as a 24-week, randomized, double-blind, placebo-controlled clinical trial. The study enrolled patients with confirmed wAIHA for at least three months, hemoglobin levels below 10 g/dL, evidence of active hemolysis and a positive direct antiglobulin test (DAT) indicating antibodies targeting red blood cells. Participants had also previously received or were currently receiving treatment for wAIHA, representing a population with substantial unmet treatment needs. A total of 118 patients were randomly assigned to three treatment groups: Imaavy at 30 mg/kg administered by intravenous infusion every four weeks, Imaavy at 15 mg/kg every two weeks, or placebo. Patients could continue stable doses of other medicines used for wAIHA during the study. The primary measure of treatment effectiveness was a durable hemoglobin response, reflecting a sustained improvement in red blood cell levels.
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Durable Hemoglobin Response Demonstrated
The trial demonstrated a higher proportion of patients achieving a durable hemoglobin response with the 30 mg/kg Imaavy regimen compared with placebo. Specifically, 24% of patients receiving Imaavy 30 mg/kg achieved a durable hemoglobin response, compared with 8% of patients receiving placebo. The 15 mg/kg treatment arm did not demonstrate a higher proportion of patients with a durable hemoglobin response compared with placebo. These findings formed the clinical basis for the FDA’s authorization of Imaavy for eligible patients aged 12 years and older. The safety profile identified peripheral edema, diarrhea and fever among the most common adverse reactions reported in patients treated with Imaavy for wAIHA. Other reported reactions included infusion-related effects such as headache, fatigue, influenza-like illness, rash, nausea, dizziness, chills and erythema. The FDA had previously granted Fast Track, Priority Review and Orphan Drug designations to Imaavy for this indication, underscoring the unmet medical need associated with wAIHA. The approval gives clinicians a new FDA-authorized treatment option for a rare autoimmune blood disorder where treatment has historically relied on therapies not specifically approved for wAIHA.
Source: FDA press release
