Riociguat Clinical Effects Studied in Patients With Insufficient Treatment Response to Phosphodiesterase-5 Inhibitor

An Open-label, International, Multicenter, Single-arm, Uncontrolled, Phase IIIb Study of Riociguat in Patients With Pulmonary Arterial Hypertension (PAH) Who Demonstrate an Insufficient Response to Treatment With Phosphodiesterase-5 Inhibitors (PDE-5i)

BAY63-2521 Riociguat leads to the relaxation of smooth muscle cells in pulmonary arteria and may also inhibit abnormal remodeling of lung blood vessels. In patients with pulmonary arterial hypertension Riociguat showed to reduce the pulmonary blood pressure and improved the right heart function without unacceptable side effects. Here dose of Riociguat will be adjusted over 8 weeks then a Maintenance Phase of 16 weeks follows. Patients with Pulmonary Arterial Hypertension treated with stable doses of Phosphodiesterase Type-5 Inhibitors (Eg Sildenafil, Tadalafil) not appropriately responding to therapy will be included. Based on previous evidence and on the different modes of action an improvement of exercise capacity, heart function and quality of life may be expected if PDE5i treatment is transitioned to riociguat.

Where Riociguat is pending market approval or reimbursement once the treatment phase is completed drug can be made available for another 18 months (Extended Drug Supply Phase - EDSP) under study conditions. Patients may also transition at the end of the maintenance period or any time during the EDSP to any program that is intended to provide riociguat until drug approval/reimbursement, e.g. a long-term extension study, compassionate use or named patient program. Study termination is also possible at any time.

Inclusion Criteria:

• Male or female patients (18 -75 years of age) with idiopathic, familial, drug/toxin induced and associated PAH due to congenital heart disease (Group I / Dana Point Classification of PH) demonstrating insufficient response to treatment with PDE-5i for at least 3 months
• Patients with and without endothelin receptor antagonist (ERA) therapy
• World Health Organization Functional Class (WHO FC) III at screening
• 6-minute walking distance (6MWD) of 165-440 m
• Cardiac index <3.0 L/min/m*2.

Exclusion Criteria:

• All types of PH except subtypes of Dana Point Group I specified in the inclusion criteria
• Evidence of clinically significant restrictive or obstructive parenchymal lung diseases
• Diffusing capacity of the lung for carbon monoxide (DLCO) <30% predicted
• History or active state of serious hemoptysis / pulmonary hemorrhage including those managed by bronchial artery embolization
• Patients unable to perform a valid 6MWD test
• Pregnant women (i.e. positive pregnancy test or other signs of pregnancy), or breast feeding women, or women with childbearing potential not using a combination of 2 effective methods of birth control, for example a combination of condoms with a safe and highly effective contraception method (prescription oral contraceptives, contraceptive injections, contraceptive patch, intrauterine device) or a double barrier method is used throughout the study.