Bayer reported positive data from a Phase III study evaluating riociguat (Bay 63-2521) in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) or with persistent/recurrent pulmonary hypertension (PH) following surgery. Data from the Chest-1 study confirmed that therapy using the oral soluble guanylate cyclase (sGC) stimulator led to statistically significant improvements in six-minute walk distance (6MWD). The Chest-1 results come just a couple of days after Bayer reported positive results from an ongoing Phase III trial (Patent-1) evaluating riociguat in the treatment of pulmonary arterial hypertension.
The placebo-controlled 16 week Chest-1 study involved 261 patients with inoperable CTEPH or with persistent/recurrent pulmonary hypertension after pulmonary endarterectomy. The results showed that therapy with riociguat led to significant improvements in the 6MWD primary endpoint, and a number of secondary endpoints, including pulmonary vascular resistance, N-terminal prohormone brain natriuretic peptide, and WHO functional class. Other secondary endpoints, including time to clinical worsening, Borg dyspnea score, European quality of life 5-dimension questionnaire, and the living with pulmonary hypertension questionnaire, weren’t met in terms of statistically significant improvements.
Results to date from the Phase III riociguat program indicate the drug may represent a potential new option for treating CTEPH, states Hossein Ardeschir Ghofrani, M.D., lead Chest-1 trial investigator at University Hospital Giessen and Marburg (Germany). “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 after surgery.”