Chest-1 is a Phase III multi-center, double-blind, randomized, placebo-controlled trial in patients with inoperable chronic thromboembolic pulmonary hypertension. The trial will involve 270 patients who will be randomized to receive either riociguat or placebo for 16 weeks. The treatment success will be measured as the change from baseline in patients’ exercise capacity, using the six-minute walking distance test.
This standard test has been used as a primary endpoint in previous pivotal clinical studies in patients with pulmonary hypertension. After the 16-week treatment in Chest-1, all patients will have the opportunity to participate in an open-label, long-term study (Chest-2) during which longer-duration safety and efficacy aspects will be assessed.
Patent-1 is a Phase III multi-center, double-blind, randomized, placebo-controlled trial in patients with pulmonary arterial hypertension who are either treatment-naïve or are being treated with an endothelin receptor antagonist or a prostacyclin analog. The trial will involve 460 patients who will be randomized to receive either riociguat or placebo.
The primary endpoint will be the change from baseline in the six-minute walking distance test after 12 weeks of treatment with riociguat compared to the change in the placebo group. After this study, all patients will have the opportunity to participate in an open-label, long-term study (Patent-2) during which longer-duration safety and efficacy aspects will be assessed. First results from Chest-1 and Patent-1 are currently expected in 2011.
Frank Misselwitz, head of global clinical development for cardiovascular diseases at Bayer Schering Pharma, said: Riociguat has the potential to overcome the disadvantages of current standard therapies. With the two trials -Chest-1 and Patent-1 – we are stepping up our commitment, particularly in indications where a high unmet medical need still exists.