The drawbacks of current therapies and the lack of an approved as needed (PRN) treatment for PAH that improves exercise ability and quality of life, form the basis for development of RT234 (inhaled vardenafil). The current study will identify the effective dose(s) of RT234 to acutely improve pulmonary vascular hemodynamics when delivered in a dose escalation manner in subjects with World Health Organization (WHO) Group 1 PAH undergoing RHC. In addition, this study will also provide valuable efficacy and safety insights into the interactions between RT234 and background disease-specific PAH therapy on pulmonary hemodynamics and right heart function.
This multicenter, open label, Phase 2a study is designed to evaluate the effect of inhaled RT234 delivered in a dose escalation manner on the change in pulmonary vascular resistance (PVR) in subjects with Pulmonary Arterial Hypertension (PAH) undergoing Right heart catheterization (RHC).~This study is also known as Vardenafil Inhaled for Pulmonary Arterial Hypertension PRN Phase 2a (VIPAH-PRN 2a) study