Biologic Drug Receives FDA Approval for Eosinophilic Granulomatosis with Polyangiitis

A high number of patients with eosinophilic granulomatosis treated with mepolizumab achieve remission within 24 weeks compared with placebo patients.

The FDA today expanded the indication of mepolizumab (Nucala) for the treatment of adults with eosinophilic granulomatosis with polyangiitis (EGPA), which causes vasculitis.

Mepolizumab is an interleukin-5 antagonist monoclonal antibody and is the first drug to receive approval for the rare autoimmune disease, according to a press release.

Patients with EGPA experience asthma, high levels of eosinophils, and inflammation of small- and medium-sized blood vessels, according to the National Institutes of Health. The inflammation can have adverse effects on various organs, including the lungs, gastrointestinal tract, skin, heart, and nervous system, according to the release. Only 10.7 to 14 per 1 million adults have this rare disease, the FDA reported.

“Prior to today’s action, patients with this challenging, rare disease did not have an FDA-approved treatment option,” said Badrul Chowdhury, MD, PhD, director of the Division of Pulmonary, Allergy, and Rheumatology Products in the FDA Center for Drug Evaluation and Research. “The expanded indication of Nucala meets a critical, unmet need for EGPA patients. It’s notable that patients taking Nucala in clinical trials reported a significant improvement in their symptoms.”

The safety and efficacy of mepolizumab was based on a 52-week clinical trial in which patients received 300-mg of mepolizumab or placebo. Patients continued treatment with oral corticosteroids, but doses were tapered at 4 weeks.

The primary efficacy endpoint was the number of patients achieving disease remission while taking a 4-mg or lower dose of prednisone, according to the FDA. The investigators found that patients treated with mepolizumab had a higher remission rate compared with the placebo group.

Additionally, more mepolizumab-treated patients achieved remission at weeks 36 and 48 compared with patients in the placebo cohort, according to the release.

More patients treated with mepolizumab were observed to achieve remission within the first 24 weeks of therapy and sustained remission for the full length of the study compared with patients in the placebo cohort, the FDA reported.

Common adverse events associated with mepolizumab include headache, injection site reaction, back pain, and fatigue.

Previously, mepolizumab was granted priority review and orphan drug designations for the expanded indication.

Mepolizumab is currently indicated to treat patients 12 years and older with severe asthma with an eosinophilic phenotype. The biologic is injected into the upper arm, thigh, or abdomen every 4 weeks.