Bayer HealthCare Pharmaceuticals, the U.S.-based pharmaceuticals business of Bayer HealthCare, issued data from the phase III PATENT-1 pulmonary arterial hypertension (PAH) trial evaluating its investigational drug riociguat in both treatment-naive patients and those pre-treated with an endothelin receptor antagonist or an oral, inhaled or subcutaneous prostanoid.

The study met its primary endpoint by demonstrating 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] (p<0.0001) after 12 weeks compared with placebo. 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 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," said Professor Hossein Ardeschir Ghofrani of University Hospital Giessen and Marburg, Germany, and 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."

Statistically significant improvements were also observed across secondary endpoints including pulmonary vascular resistance (PVR) (p<0.0001), N-terminal prohormone brain natriuretic peptide (NT-pro BNP) (p<0.0001), WHO functional class (FC) (p=0.0033), time to clinical worsening (TTCW) (p=0.0046) and Borg dyspnea score (p=0.0022). Secondary endpoints that did not achieve statistical significance, including the European quality of life 5-dimensions questionnaire (EQ-5D) (p=0.0660) and living

The most frequent treatment emergent adverse events were headache, dyspepsia, peripheral edema, nausea, dizziness, diarrhea, nasopharyngitis, dyspnea, cough and vomiting.