J&J’s Imaavy approved in Brazil for warm autoimmune hemolytic anemia, becoming first treatment for the disease

Brazil’s Health Regulatory Agency (ANVISA) has approved Johnson & Johnson’s nipocalimab (brand name Imaavy) to treat warm autoimmune hemolytic anemia (wAIHA). It is the first treatment approved for the disease.

According to Johnson & Johnson, ANVISA approved Imaavy for patients 12 years and older with warm autoimmune hemolytic anemia on the 27th (local time). Warm autoimmune hemolytic anemia is a rare disease in which autoantibodies destroy red blood cells, causing severe anemia and weakness, and it can be life-threatening.

The approval brings Brazil its first treatment specifically for the disease. Until now, treatment has relied mainly on corticosteroids and broad immunosuppressants. These drugs act on the entire immune system rather than targeting the autoantibodies that cause the disease.

“Living with warm autoimmune hemolytic anemia often means coping with severe fatigue and weakness, as well as an unpredictable clinical course,” said Renato Sampaio Tavares, MD, a board member of the Brazilian Society of Hematology, Hemotherapy and Cellular Therapy (ABHH) and the Brazilian Association of Lymphoma and Leukemia (ABRALE), and coordinator of the Hematology Research Center at Hospital das Clínicas of the Federal University of Goiás (HC-UFG).

“Many patients experience cycles of improvement and relapse, with hemoglobin levels falling and symptoms returning,” he continued. “For years, treatment options were limited and most were borrowed from other diseases. Now, for the first time, we have a treatment specifically for this disease.”

The approval was based on the phase 2/3 ENERGY clinical trial. Its primary endpoint was sustained hemoglobin response, defined as a hemoglobin concentration of at least 10g/dL and an increase of at least 2g/dL from baseline, maintained for at least 28 days.

In the randomized, placebo-controlled trial, patients who received the approved dose of Imaavy were about 3 times as likely as those in the placebo group to achieve a sustained hemoglobin response at week 24. The result was statistically significant.

Patients receiving Imaavy also had a mean increase in hemoglobin of 1g/dL by week 1, while there was no change in the placebo group. Among patients who responded, the median time to first hemoglobin response was 4.1 weeks (range, 1~12 weeks) in the Imaavy 30mg/kg every 4 weeks group, shorter than the 12.1 weeks (range, 4~16 weeks) in the placebo group. However, this analysis was not included in the hierarchical testing procedure.

Improvement in fatigue was also observed. At week 24, the Imaavy group showed a mean improvement of 3.51 points over the placebo group on the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue) scale. Higher scores on this scale indicate less fatigue. However, under the prespecified statistical analysis plan, this result is considered descriptive and is not confirmatory.

“The ENERGY trial showed that blocking pathogenic immunoglobulin G (IgG) autoantibodies can provide meaningful benefits for patients with warm autoimmune hemolytic anemia,” Tavares said. “A higher proportion of patients receiving Imaavy than placebo had a hemoglobin response and improvement in fatigue.”

The company said he was one of the trial’s global principal investigators (PIs) and helped put Brazil at the forefront of clinical research into rare blood diseases.

In terms of safety, Imaavy showed a profile consistent with that observed in its previously approved indication for generalized myasthenia gravis (gMG). The most common adverse reactions (10% or more) in patients with warm autoimmune hemolytic anemia were peripheral edema, diarrhea and fever.

Full results from the ENERGY trial were presented at the European Hematology Association (EHA) Congress in June 2026.

Imaavy is an immunoselective treatment designed to bind with high affinity to and block the neonatal Fc receptor (FcRn), reducing circulating IgG antibodies that cause disease while preserving essential immune system functions.

“This approval has the potential to positively affect current treatment management, particularly for patients whose disease is not adequately controlled,” said Damila Trupelli, medical director of Johnson & Johnson Innovative Medicine in Brazil. “It is an important advance for people in Brazil with warm autoimmune hemolytic anemia, who have historically had limited treatment options.”

Imaavy is already marketed in Brazil after its approval in September 2025 to treat generalized myasthenia gravis in adults and pediatric patients 12 years and older who test positive for antibodies to acetylcholine receptor (AChR), muscle-specific tyrosine kinase (MuSK) or low-density lipoprotein receptor-related protein 4 (LRP4).

The U.S. Food and Drug Administration (FDA) granted Imaavy its first approval for warm autoimmune hemolytic anemia on Aug. 24, 2026.

ENERGY (NCT04119050) is a multicenter, randomized, double-blind, placebo-controlled phase 2/3 trial comparing nipocalimab with placebo in adults with warm autoimmune hemolytic anemia, followed by an open-label extension period. A total of 115 adults were randomized in an approximately 1:1:1 ratio to receive one of two nipocalimab regimens or placebo.

Patients who completed 24 weeks of double-blind treatment could enter an open-label extension period in which they received nipocalimab for 144 weeks, followed by a 6-week follow-up period after the final assessment.

The approved dose is 30mg/kg administered intravenously every 4 weeks. Sustained hemoglobin response was achieved with statistical significance on this regimen, but not in the 15mg/kg intravenous group administered every 2 weeks, which was also evaluated in the trial.

Warm autoimmune hemolytic anemia is a rare disease in which autoantibodies bind to and destroy red blood cells, causing anemia. Epidemiologic data from Brazil are limited, but worldwide, an estimated 1~3 new cases occur per 100,000 people each year, and about 1 in 8,000 people is estimated to have the disease.

The disease can affect both men and women and occur at any age, with incidence increasing after age 50. Patients are at higher risk of serious complications, including venous thromboembolism, acute kidney failure and infection.

Imaavy’s legal manufacturer is Janssen Biotech.