FDA Approves First Treatment for Warm AIHA

Written by Ted Samson

Posted on September 10, 2026

Feel better informed on AIHA and get real support from your community.

The U.S. Food and Drug Administration (FDA) approved nipocalimab-aahu (Imaavy) in late August 2026. Imaavy is the first FDA-approved treatment for warm autoimmune hemolytic anemia (wAIHA).

The approval gives people with wAIHA a new treatment option to discuss with their hematology team.

What Is Imaavy?

Imaavy is a neonatal Fc receptor (FcRn) blocker. FcRn helps keep immunoglobulin G (IgG) antibodies in the bloodstream. Blocking FcRn reduces circulating IgG, including IgG autoantibodies that can contribute to red blood cell destruction in wAIHA.

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The drug is indicated for adults and children ages 12 and older who are currently or were previously treated with corticosteroids. It’s given as an IV infusion.

What Did Clinical Trials Show?

The approval was based on ENERGY, a phase 2/3 study of 118 adults with confirmed wAIHA. For 24 weeks, participants were placed by chance into three groups: Imaavy at 30 milligrams per kilogram every four weeks, Imaavy at another dosing schedule, or a placebo (an inactive treatment). Neither participants nor researchers knew which treatment participants were receiving.

The study measured whether participants had a durable hemoglobin response. Hemoglobin carries oxygen in red blood cells, and a durable response meant that hemoglobin levels improved and stayed higher over time.

In the 24-week comparison period, 24 percent of people who received the approved 30-milligram-per-kilogram dose had a durable hemoglobin response, compared with 8 percent of people who received a placebo.

What Are the Side Effects?

As with any medication, Imaavy may cause side effects. According to the FDA, the most common side effects are peripheral edema (swelling caused by fluid buildup), diarrhea, and pyrexia (fever).

What Does This Approval Mean for People With Warm AIHA?

Warm AIHA is rare, with an estimated 1 to 3 cases per 100,000 people each year. It can develop at any age. Until now, there were no FDA-approved treatments specifically indicated for the condition.

The approval adds an FDA-approved option to treatment plans that may also include corticosteroids and other therapies.

If you’re living with wAIHA and aren’t getting the desired results from your current treatment plan, consider speaking with your hematology team. Together, you can work to find a plan that fits your needs.