Riociguat rEplacing PDE-5i Therapy evaLuated Against Continued PDE-5i thErapy

Film-coated tablets will be used in this study at a dosage of 0.5 mg, 1.0 mg, 1.5 mg, 2.0 mg and 2.5 mg. Tablets will be administered orally.The starting dose is 1 mg TID; the intervals between drug intakes should be 6 to 8 hours. The dosage should be increased by 0.5 mg increments in 2 week intervals to 1.5 mg, 2.0 mg, and 2.5 mg TID (maximal total daily dose).

Patients randomized to the control arm will continue to receive stable doses of tadalafil (daily dose 20 to 40 mg) or sildenafil (daily dose at least 60 mg) as well as other supportive treatments at the discretion of the investigator.

Patients randomized to the control arm will continue to receive stable doses of tadalafil (daily dose 20 to 40 mg) or sildenafil (daily dose at least 60 mg) as well as other supportive treatments at the discretion of the investigator.