GSK has filed a regulatory submission to the European Medicines Agency (EMA) for a variation to the Marketing Authorisation for ambrisentan (Volibris), to extend the current therapeutic indication to include its use in initial combination therapy for patients with pulmonary arterial hypertension (PAH).

The submission to the EMA is based on the results of the phase IIIb/IV AMBITION study, conducted in collaboration with Gilead Sciences Inc., which investigated the initial combination therapy of ambrisentan and tadalafil in treatment naïve PAH patients with WHO functional class II and III symptoms.

PAH, a debilitating disease affecting approximately 200,000 patients worldwide, is characterised by constriction of the blood vessels in the lungs leading to high pulmonary arterial pressures.  These high pressures make it difficult for the heart to pump blood through the lungs to be oxygenated.  Patients with PAH suffer from shortness of breath as the heart struggles to pump against these high pressures, causing such patients to ultimately die of heart failure.  

“We hope that evidence from the AMBITION study, which showed that starting initial combination of ambrisentan and tadalafil was superior to first-line monotherapy with either medicine alone, will help support the management of patients who suffer with this rare and debilitating lung disease” said Dr. Carlo Russo, senior vice president, head of GSK rare diseases research & development.  “This submission has been part of our efforts to continue to help patients with pulmonary arterial hypertension and we look forward to the outcome.

Further regulatory submissions are planned in other countries during the course of 2014 and 2015.

Ambrisentan, a selective endothelin type-A receptor antagonist, is currently approved in the European Union (EU) for the treatment of adult patients with PAH classified as WHO functional class II and III, to improve exercise capacity.

GSK commercialises ambrisentan under the trade name Volibris® in territories outside of the United States and Gilead commercialises ambrisentan under the trade name Letairis in the US.  Ambrisentan has been granted orphan drug status for the treatment of PAH in Australia, Europe, Japan, Korea and United States.

Letairis and Volibris are registered trademarks of Gilead Sciences, Inc or one of its related companies.