The U.S. Food and Drug Administration (FDA) Wednesday approved GlaxoSmithKline’s (GSK) Nucala (Ingredient: mepolizumab) to treat adult patients with eosinophilic granulomatosis with polyangiitis (EGPA). The new treatment is the first FDA approved therapy specifically for EPGA.

EGPA, formerly known as Churg-Strauss Syndrome, is a rare autoimmune disease that causes vasculitis, an inflammation of the wall of blood vessels of the body. The inflamed vessels can affect various organ systems, including lungs, gastrointestinal tract, skin, heart and nervous system. Other symptoms include asthma and high levels of eosinophils, which are a type of white blood cells that help fight infection.

Nucala is an interleukin-5 antagonist monoclonal antibody (IgG1 kappa) produced by recombinant DNA technology in Chinese hamster ovary cells. The drug is administered once every four weeks through subcutaneous injection by a healthcare professional into the upper arm, thigh or abdomen.

The safety and efficacy of Nucala were analyzed in a 52-week treatment clinical trial that compared Nucala to placebo. Patients received 300 milligrams of Nucala or placebo administered subcutaneously once every four weeks while continuing their stable daily oral corticosteroids (OCS) therapy.

The primary efficacy assessment in the trial measured Nucala’s treatment impact on disease remission while on an OCS dose less than or equal to 4 milligrams of prednisone. As a result, patients receiving Nucala achieved a significantly greater accrued time in remission compared with placebo. Common adverse reactions associated with Nucala in clinical trials included a headache, injection site reaction, back pain, and fatigue.

However, the drug should not be administered to patients with a history of hypersensitivity to mepolizumab or one of its ingredients.

“Before today’s action, patients with this challenging, rare disease did not have an FDA-approved treatment option,” said Badrul Chowdhury, director of the Division of Pulmonary, Allergy, and Rheumatology Products in the FDA’s 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.”