GlaxoSmithKline’s biologic Nucala has become the first therapy specifically approved in the US to treat a rare disease called eosinophilic granulomatosis with polyangiitis (EPGA).

EGPA (formerly known as Churg-Strauss syndrome) is an autoimmune disease that causes vasculitis, an inflammation in the wall of blood vessels of the body.

The condition is characterised by asthma, high levels of eosinophils, and inflammation of small- to medium-sized blood vessels affecting various organ systems in the body.

Nucala (mepolizumab) is an interleukin-5 antagonist monoclonal antibody (IgG1 kappa) produced by recombinant DNA technology in Chinese hamster ovary cells.

The drug was first approved in the US in 2015 to treat patients with severe eosinophilic asthma whose disease remains uncontrolled despite medication.

Its expanded approval comes after clinical data from the Phase III MIRRA trial showed that patients with EPGA receiving 300mg of Nucala achieved a significantly greater accrued time in remission compared with placebo.

“Patients suffering from EGPA too often face a frustrating journey from a delay in receiving a proper diagnosis to having few effective treatment options with an acceptable safety profile,” noted Peter Merkel, chief, Division of Rheumatology at Perelman School of Medicine, University of Pennsylvania & MIRRA study site investigator.

The approval of Nucala “provides specialists with the ability to offer a targeted treatment to appropriate patients with this complex disease.”

Michael Wechsler, Professor of Medicine at National Jewish Health in Denver, Colorado, US & principal investigator of the MIRRA study, also highlighted that patients with EGPA often suffer from recurrent relapses leaving them at greater risk of permanent tissue and organ damage.

“Clinical data demonstrated that mepolizumab increased accrued time in remission, reduced the frequency of relapse and flares, and enabled patients to have their dose of corticosteroid reduced compared to placebo in patients already receiving standard of care. These are key treatment goals and this approval is an important milestone both for treating physicians and for patients.”