To assess the long-term safety of macitentan in patients with pulmonary arterial hypertension (PAH) beyond treatment in the AC-055-310 study.
Prospective, multi-center, open-label, single-arm, Phase 3b extension study of macitentan in patients with PAH.~To assess the long-term safety of macitentan in patients with pulmonary arterial hypertension (PAH) beyond treatment in the AC-055-310 study.