Evaluation of the Pharmacodynamic Effect of the Combination of Sildenafil and Riociguat on Blood Pressure and Other Safety Parameters.

Study Summary

Pulmonary Arterial Hypertension (PAH) is a severe progressive disease with a high mortality. Although several drugs are available for the treatment of PAH none offer a cure, therefore there is still a high medical need for new treatments. Soluble guanylate cyclase (sGC) is one of the chemicals involved in the pathways controlling vascular tone, which is impaired in patients with PAH. This causes constriction and thickening of the blood vessels wall in the lungs and increase of blood pressure in the lungs. This can lead to the very debilitating symptoms of PAH such as tiredness, shortness of breath on exertion, collapse and often the inability of the patient to perform their daily life activities. Inhalation of Nitric Oxide, which activates sGC is used to treat PAH, but its effect wears off as soon as inhalation stops. Direct stimulation of sGC using this new compound Riociguat may be a new approach for the treatment of PAH. The phosphodiesterase 5 (PDE5)-inhibitor Sildenafil is one of licensed treatments for PAH. The Patent Plus is a double-blind, placebo-controlled safety study, designed to investigate the effect of Riociguat on blood pressure in patients with PAH when given in combination with Sildenafil.

Primary Outcome

Systolic blood pressure (SBP) was measured as standard vital sign parameter. Range allowed in this study: \<= 180 mmHg. In addition, SBP must be \>=95 mmHg in the first 2 hours after intake of background treatment with sildenafil. The maximum change from baseline at each visit was defined as the within-subject maximum decrease from baseline (or zero if baseline was lower than all subsequent SBP measurements in that profile) within 4 hours post-dose. Baseline was the last SBP recorded at and with

Interventions

• DRUG Placebo
• DRUG Sildenafil
• DRUG Riociguat (Adempas, BAY63-2521)