Source: Press release
September 25, 2020
2 min read

FDA grants new indication for mepolizumab in hypereosinophilic syndrome

Source: Press release
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The FDA has approved mepolizumab for certain adults and children with hypereosinophilic syndrome, according to a press release.

The approval of mepolizumab (Nucala, GlaxoSmithKline) applies to adults and children 12 years and older who have had hypereosinophilic syndrome (HES) for 6 months or longer and who do not have another identifiable nonblood-related cause of the disease.

This is the first approval for patients with HES in nearly 14 years.

The FDA’s decision was based on data from a randomized, double-blind, multicenter, placebo-controlled trial in which 108 patients were assigned mepolizumab or placebo injections every 4 weeks. At least one HES flare — defined as a worsening of clinical signs and symptoms or elevated eosinophils — over 32 weeks of treatment served as the primary outcome measure.

Results showed that 28% of patients in the study-drug arm experienced this outcome, compared with 56% for placebo, which the researchers described as a 50% relative reduction. Moreover, patients treated with mepolizumab experienced a longer time to first flare than those in the placebo group.

Herpes zoster, upper respiratory tract infections and pain in the extremities were the most commonly reported adverse events of mepolizumab. The drug is also contraindicated in individuals who have shown a hypersensitivity to it, or one of its ingredients, according to FDA officials.

The heterogeneous group of rare disorders that full under the umbrella of HES is marked by persistent eosinophilia that may lead to organ damage. Patients with these conditions may experience skin rashes and itching, along with pulmonary complications such as asthma and difficulty breathing. Gastrointestinal manifestations may range from abdominal pain to vomiting and diarrhea, while arthritis and muscle inflammation may occur, along with congestive heart failure, deep venous thrombosis or anemia.

Mepolizumab previously received an orphan drug designation for the treatment of HES, granting manufacturers fast track designation and priority review.

Other indications for mepolizumab include one for severe asthma with an eosinophilic phenotype in patients ages 6 and older and for adults who have eosinophilic granulomatosis with polyangiitis.

“Today’s approval marks the first time in over a decade that there is a new FDA-approved treatment option for patients with hypereosinophilic syndrome,” said Ann Farrell, MD, director of the Division of Nonmalignant Hematology in the FDA’s Center for Drug Evaluation and Research. “FDA is committed to helping develop safe and effective treatment options for this group of rare and debilitating blood diseases and other rare conditions.”