Bayer reported positive data from an ongoing Phase III Patent-1 study evaluating the oral guanylate cyclase (sGC) stimulator riociguat (BAY 63-2521) as a treatment for pulmonary arterial hypertension (PAH) in treatment-naïve patients and those who have previously received an endothelin receptor antagonist or prostanoid therapy.
Results from the placebo-controlled trial showed that both treatment-naïve and pretreated patients given riociguat demonstrated a stastistically significant improvement in six-minute walk distance (6MWD) over a 12-week period. Statistically significant improvements in secondary endpoints were also recorded, including pulmonary vascular resistance, N-terminal prohormone brain natriuretic peptide, WHP functional class, time to clinical worsening, and Borg dyspnea score.
"The six-minute walk distance test is a well-validated clinical measure in patients with PAH, and therefore, the results of the Patent-1 trial are encouraging," comments Hossein Ardeschir Ghofrani, M.D., at University Hospital Giessen and Marburg (Germany), who is principal investigator of the Patent study. "These data from the Patent study suggest that riociguat may be a potential treatment option both for patients who have never been treated for PAH as well as for those who have received prior treatment."
The multinational Phase III Patent program for riociguat involves the 12-week Patent 1 study, which has enrolled 445 patients with symptomatic PAH, and an open-label extension study, Patent-2. In addition to PAH, riociguat is currently undergoing development for other types of pulmonary hypertension, including chronic thromboembolic pulmonary hypertension (CTEPH). Data from the first stage of the Phase III CHEST study evaluating oral riociguat in patients with CTEPH are due for presentation at a forthcoming congress.