Riociguat for Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension

Limited options are available for treating patients with pulmonary hypertension. Initial trials of riociguat, an oral medication that stimulates guanylate cyclase and enhances nitric oxide activity, yielded encouraging results in patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTPH). Now, investigators report results of two international, industry-supported, phase III trials. In one study, researchers tested riociguat (maximum dose of 2.5 mg, thrice daily) versus placebo in 261 patients with CTPH deemed to be inoperable or persisting after surgery. In the other study, 443 patients with PAH were randomized to placebo or riociguat at a maximal dose of 2.5 mg. Half the PAH patients receive…