Clinical Study to Compare the Efficacy and Safety of Macitentan and Tadalafil Monotherapies With the Corresponding Fixed-dose Combination Therapy in Subjects With Pulmonary Arterial Hypertension

This study aims to demonstrate that the FDC of macitentan and tadalafil is more effective than therapy with 10 mg of macitentan alone or 40 mg of tadalafil alone. This phase 3 study will evaluate the efficacy and safety at 16 weeks of an FDC (macitentan 10 mg and tadalafil 40 mg) against these two PAH-approved therapies given as monotherapy to further confirm the added value of the FDC.