- Current diagnosis of PAH (WHO Group 1) with WHO class II or III symptoms in one of the following categories: Idiopathic, Heritable [familial], Secondary to connective tissue disease (e.g., limited scleroderma, diffuse scleroderma, mixed connective tissue disease (CTD), systemic lupus erythematosus, or overlap syndrome), or Persistent PAH despite surgical repair (at least 6 months prior to the screening visit) of atrial septal defects, ventricular septal defects, atrio-ventricular septal defects, and persistent patent ductus.