Phase 1b Study of HS235 Assessing the Safety, Pharmacokinetics, Pharmacodynamics, and Efficacy of the Activin Signaling Inhibitor HS235 Added to Background Treatment in Adults with Pulmonary Arterial Hypertension (PAH)

A Phase Ib, Multicenter, Randomized, Double-Blind, Placebo-Controlled, Dose-Ranging Study Assessing the Safety, Pharmacokinetics, Pharmacodynamics, and Efficacy of the Activin Signaling Inhibitor HS235 Added to Background Treatment in Adults with Pulmonary Arterial Hypertension (PAH)

Inclusion Criteria:

Patients are eligible to be included in the study only if they meet all of the following criteria:

1. Male and female patients, 18 years of age and older.
2. Body Mass Index (BMI) 18.5 and 40 kg/m2 and body weight at or below 120 kg.
3. Baseline Right Heart Catheterization (RHC) performed during the Screening Period documenting minimum pulmonary vascular resistance (PVR) of ≥ 5 Wood units (WU) or ≥ 400 dyn·sec·cm-5 and a pulmonary artery wedge pressure (PAWP) of ≤ 15 mm Hg.
4. Diagnosis of WHO pulmonary arterial hypertension (PAH) Group 1.
5. Symptomatic PAH classified as WHO Functional class II to IV.
6. On stable doses of at least 2 approved background PAH therapies and diuretics for at least 90 days prior to Screening.
7. 6-Minute Walk Distance (6MWD) ≥ 150m and ≤ 500m repeated twice during screening.
8. Ability to adhere to study visit schedule and understand and comply with all protocol requirements.

Exclusion Criteria:

1. Hospitalization for any worsening medical condition or major surgery within 4 weeks prior to screening.
2. Any symptomatic coronary disease events within 6 months of the screening visit.
3. History of heart transplant or on heart transplant list.
4. Uncontrolled systemic hypertension.
5. History of restrictive, constrictive or congestive cardiomyopathy.
6. History of significant valvular stenosis or regurgitation.
7. Untreated or poorly controlled moderate or severe obstructive sleep apnea.