FDA Grants Priority Review to Mepolizumab for Hypereosinophilic Syndrome

Officials with the FDA have granted priority review for mepolizumab (Nucala, GlaxoSmithKline [GSK]) in the treatment of patients with hypereosinophilic syndrome (HES), according to a press release.

If approved, mepolizumab would be the first targeted biologic treatment for this patient population, according to GSK. Mepolizumab has already been granted both fast track and orphan drug designation for HES by the FDA.

HES is a rare and under-diagnosed disorder in which patients have persistent and marked overproduction of eosinophils. Complications can range from fever and malaise to respiratory and cardiac problems. Treatment options for HES are currently limited.

Mepolizumab, the first-in-class monoclonal antibody that targets interleukin-5, was initially approved in 2015 by the FDA for severe eosinophilia asthma. The drug is also indicated for the treatment of eosinophilic granulomatosis with polyangiitis.

Priority review for the HES indication is based on positive results from a phase 3 study, which evaluated the safety and efficacy of subcutaneous mepolizumab 300 mg every 4 weeks compared with a placebo in adolescents and adult patients with uncontrolled HES. A total of 108 patients were enrolled in the 32-week, randomized, double-blind, placebo-controlled study.

According to the results, statistically significantly fewer patients experienced a HES flare or withdrawal for the study when treated with mepolizumab, compared with placebo, when added to standard of care. All secondary end points were also statistically significant in favor of mepolizumab compared with placebo.

Mepolizumab is currently also being investigated in several other eosinophilic-driven diseases

References:

1. FDA grants priority review of Nucala for patients with Hypereosinophilic Syndrome (HES). News Release. GlaxoSmithKline; May 27, 2020. Accessed May 27, 2020. https://www.gsk.com/en-gb/media/press-releases/fda-grants-priority-review-of-nucala-for-patients-with-hypereosinophilic-syndrome-hes/.