Phase III trial of BAY 63-2521 (Bayer HealthCare) for PAH meets primary endpoint

The Phase III PATENT-1 Pulmonary Arterial Hypertension (PAH) trial evaluating BAY 63-2521 (riociguat), from Bayer HealthCare, in both treatment-naive patients and those pre-treated with an endothelin receptor antagonist or an oral, inhaled or subcutaneous prostanoid has met its primary endpoint. PATENT is an international program with active centers in 32 countries. It includes a randomized, double-blind, placebo-controlled trial phase (PATENT-1) and an open label extension trial phase (PATENT-2). In the PATENT-1 study, 445 patients with symptomatic PAH were randomized to receive either placebo or two different doses of riociguat orally over a period of 12 weeks.

Led by Professor Hossein Ardeschir Ghofrani of University Hospital Giessen and Marburg, Germany, the study demonstrated a statistically significant improvement in the six-minute walk distance (6MWD) with patients treated with riociguat showing an improvement of 36 meters 95%-CI [20-52 meters] after 12 weeks compared with placebo. Trial results also showed a statistically significant improvement in 6MWD both in the treatment-naive patient group (38 meters after 12 weeks compared with placebo [95%-CI 15-62 meters]) and the pre-treated patient group (36 meters after 12 weeks compared with placebo [95%-CI 15-56 meters]). The results will be presented at CHEST 2012, the annual meeting of the American College of Chest Physicians.