Bayer announces data from riociguat Phase III trial on CTEPH

Bayer HealthCare today announced data from the Phase III CHEST-1 trial evaluating its investigational drug riociguat in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) or with persistent or recurrent pulmonary hypertension (PH) after surgery.  The results showed the CHEST-1 study met its primary endpoint by demonstrating a statistically significant improvement in the six-minute walk distance (6MWD). In the study, patients treated with riociguat showed an improvement of 46 meters (95%-CI [25-67 meters] p<0.0001) compared to placebo. The results were presented as a late-breaking abstract in an oral abstract session at CHEST 2012, the annual meeting of the American College of Chest Physicians (ACCP) in Atlanta, Georgia (Abstract No. 1462924).

Chronic thromboembolic pulmonary hypertension (CTEPH) is a life-threatening disease in which blood clots and thromboembolic occlusion of pulmonary vessels leads to an increased pressure in the pulmonary arteries.

"These study results with investigational riociguat are encouraging because it is the first randomized Phase III trial in which a drug treatment has demonstrated significant improvement in 6MWD in patients with inoperable CTEPH or with persistent or recurrent pulmonary hypertension (PH) after surgery," said lead investigator, Professor Hossein Ardeschir Ghofrani, University Hospital Giessen and Marburg, Germany. "Results from the Phase III development program suggest that riociguat may be a potential new option in CTEPH."

The ten most frequently reported treatment-emergent adverse events with riociguat vs. placebo were: headache (25% vs. 14%), dizziness (23% vs. 13%), peripheral edema (16% vs. 21%), cough (5% vs. 18%), dyspepsia (18% vs. 8%), nasopharyngitis (15% vs. 9%), dyspnea (5% vs. 14%), nausea (11% vs. 8%), diarrhea (10% vs. 5%) and vomiting (10% vs. 3%).

In the CHEST-1 trial, riociguat also showed statistically significant improvements in secondary endpoints including pulmonary vascular resistance (PVR) (p<0.0001), N-terminal prohormone brain natriuretic peptide (NT-proBNP) (p<0.0001) and WHO functional class (FC) (p=0.0026). Secondary endpoints that did not achieve statistical significance were observed in time to clinical worsening (TTCW) (p=0.1724), Borg dyspnea score (p=0.0035), European quality of life 5-dimensions questionnaire (EQ-5D) (p<0.0001) and living with pulmonary hypertension questionnaire (LPH) (p=0.1220).

"We are pleased to present the data from the Phase III CHEST-1 trial," said Pamela A. Cyrus, M.D., Vice President and Head of U.S. Medical Affairs, Bayer HealthCare Pharmaceuticals. "There is an unmet medical need for CTEPH patients who are unable to undergo surgery, or who have persistent or recurrent PH after surgery."