GlaxoSmithKline has announced positive data from its study of Nucala (mepolizumab) Hypereosinophilic Syndrome (HES).

The pharma giant revealed that the Phase III study met its primary endpoint of fewer patients experiencing a HES flare, making Nucala the first treatment to demonstrate a reduction in flares for the rare disease.

In the trial, patients treated with the drug experienced 50% fewer flares compared to placebo, when added to standard of care treatment over the 32-week study period.

The first-in-class monoclonal antibody that targets IL-5, working by preventing IL-5 from binding to its receptor on the surface of eosinophils, reducing blood eosinophils without completely depleting them.

It has been studied in over 3,000 patients in 21 clinical trials across a number of eosinophilic indications and has been approved as Nucala in the US, Europe and in over 20 other markets, as an add-on maintenance treatment for patients with severe eosinophilic asthma (SEA).

The therapy has the potential to “change the treatment landscape for patients with HES, which is a complex and debilitating disease with limited therapeutic options today” explained Dr Hal Barron, chief scientific officer, R&D at the company.

In addition to the primary endpoint, the drug also met its secondary endpoints of fatigue, annualised rate of flare and safety.

GSK also confirmed that based on the pivotal data, it plans to progress regulatory submissions in 2020.

Currently, Nucala is not approved for use in HES - a rare group of inflammatory disorders that affects approximately 20,000 people globally - anywhere in the world. The disease has complications which can range from fever and malaise to respiratory and cardiac problems. If left untreated, the symptoms become progressively worse and the disease can be life-threatening.