After a year of being treated with a novel drug, patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) and those with persistent or recurrent pulmonary hypertension after an operation for the disease showed sustained improvement in a multicenter, international trial presented at the 2014 American Thoracic Society International Conference.
The drug, riociguat, is a guanylate cyclase stimulator that works independently and in concert with endogenous nitric oxide to induce vasodilation. A long-term extension study, CHEST-2 enrolled patients from CHEST-1, which followed these patients for 16 weeks and achieved its primary endpoint: improved six-minute walking distance (6MWD).
"The pivotal study, CHEST-1, showed significant improvements in exercise capacity and hemodynamics in patients treated with riociguat," said principal investigator Marius Hoeper, MD, of the Hannover Medical School (Germany). "However, the study was relatively short, and CHEST-2 adds important information on the long-term tolerability and efficacy of riociguat in patients with CTEPH."
CTEPH is a relatively rare disease; about 5000 people in the U.S. are diagnosed with the disease each year. It occurs when blood clots from previous episodes of acute pulmonary embolism do not resolve, causing persistent obstruction of the pulmonary vasculature, which may ultimately lead to pulmonary hypertension.