An Adaptive, 2-Part, Randomized, Double-Blind, Placebo-Controlled Trial to Evaluate the Efficacy and Safety of IKT-001 in Pulmonary Arterial Hypertension (PAH)

Inclusion Criteria: * Documented diagnosis of WHO PAH Group 1 in any of the following subtypes: * Idiopathic PAH * Heritable PAH * Drug/toxin-induced PAH * PAH associated with connective tissue disease (CTD) * PAH associated with simple, congenital systemic-to-pulmonary shunts at least 1 year following repair * Men and women 18 and 75 years of age (inclusive) * Must have a body mass index (BMI) of ≥18.5 kg/m\^2 and ≤35.0 kg/m\^2 at screening. * Baseline RHC performed during the Screening Period documenting a PVR of ≥ 400 dyn/sec/cm\^5 ; pulmonary capillary wedge pressure (PCWP) ≤15…