The Food and Drug Administration announced Dec. 12 the approval of mepolizumab (Nucala) to treat adult patients with eosinophilic granulomatosis with polyangiitis (EGPA), making it the first FDA-approved therapy intended to treat this rare disease.

Approval was based on data from a 52-week clinical trial that compared mepolizumab with placebo, according to the FDA. Patients received 300 mg of mepolizumab once every 4 weeks while continuing stable daily oral corticosteroid therapy. Those patients receiving mepolizumab “achieved a significantly greater accrued time in remission compared with placebo,” and a significantly higher proportion of patients receiving 300 mg of mepolizumab had achieved remission at week 36 and week 48, the statement said. Additionally, significantly more patients treated with mepolizumab achieved remission within the first 24 weeks and remained in remission for the remainder of the 52-week study treatment period.

Mepolizumab , an interleukin-5 antagonist monoclonal antibody, was previously approved in 2015 as add-on maintenance treatment for patients aged 12 years and older with severe asthma of an eosinophilic phenotype. It is administered once every 4 weeks by subcutaneous injection into the upper arm, thigh, or abdomen by a health care professional.

“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,” said Badrul Chowdhury, MD, PhD, director of the division of pulmonary, allergy, and rheumatology products in the FDA’s Center for Drug Evaluation and Research in the press release announcing the approval. EGPA was formerly known as Churg-Strauss syndrome, the statement pointed out.

Read the full press release on the FDA’s website.