Rodatristat Ethyl in Patients with Pulmonary Arterial Hypertension

This double-blind study will compare the efficacy, safety, and tolerability of 2 doses of rodatristat ethyl to placebo in patients with PAH. Eligible patients will be stratified during the randomization process based on the number of background PAH therapies they are receiving (1, 2 or 3) and use of selexipag (yes/no). The number of patients who are receiving a prostanoid infusion will be capped at 50% of the total number of patients enrolled. The number of patients who are receiving selexipag will be capped at 20% of the total enrolled. Patients will be randomized 1:1:1 to placebo, 300 mg BID, or 600 mg BID of rodatristat ethyl. Patients who complete the Main Study will have the option to enroll into the OLE and continue to receive rodatristat ethyl (those randomized to placebo will be re-randomized 1:1 to receive rodatristat ethyl 300 mg BID or 600 mg BID) until the Investigator or patient chooses to stop the investigational product (IP), any stopping criterion in the Main Study is met, IP becomes commercially available, or the Sponsor stops the study for lack of efficacy or a safety signal. Approximately 90 patients with PAH are expected to be enrolled at approximately 45 to 50 study sites in the U.S., Canada, and Rest of World (ROW). This is a parallel group treatment study with 3 arms that is participant, Sponsor, and Investigator blinded. The objective of the OLE is to evaluate the long-term safety, tolerability, and efficacy of rodatristat ethyl in patients with PAH.

Inclusion Criteria

• Body mass index (BMI) ≥ 18 kg/m2 and ≤ 38 kg/m2
• WHO FC II or III
• Currently on a stable treatment regimen with one or more treatments approved for PAH. Stable therapy is defined as receiving the same medication(s) for ≥ 12 weeks prior to the screening RHC and at a stable dose level for each for ≥ 8 weeks prior to the screening RHC. Any instances where doses of a medication have been missed prior to RHC must be discussed with the Medical Monitor prior to performing the RHC.

Exclusion Criteria

• Women of childbearing potential who are pregnant, planning to become pregnant, or lactating or female/male patients unwilling to use effective contraception as defined in Section 5.4.1
• PAH associated with significant venous or capillary involvement (PCWP > 15 mmHg), pulmonary capillary hemangiomatosis, portal hypertension, or unrepaired congenital heart defects (CHD)
• Known genetic hypertrophic cardiomyopathy

Study Requirements

Patients are expected to come in for approximately nine visits to the clinic. Total participation will last approximately 7-8 months. Each clinic visit will take approximately 1-5 hours. Approximately 125 mL (25 teaspoons) or 1/2 cup of blood will be collected over the 24 weeks of the study. If a patient participates in the Optional Blood Sample for Future Research an additional 20 mL (~4 teaspoons) will be collected. There are no x-rays, scans or MRIs.