NCT07143448 · 35Pharma Inc
A Study of HS235 for Treatment of Pulmonary Arterial Hypertension (PAH) in Adults
What this study is about
Phase 1b/2 Study of HS235 Assessing the Safety, how the drug moves through the body, how the drug affects the body, and effectiveness of the Activin Signaling Inhibitor HS235 Added to Background Treatment in Adults with Pulmonary Arterial Hypertension (PAH)
View original scientific description
Phase 1b/2 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)
Interventions
BIOLOGICAL
HS235
Subcutaneous Injection
OTHER
Placebo
Subcutaneous Injection
Primary outcome measures
Incidence and Number of Adverse Events (AEs)
Time frame: up to 29 weeks
An AE is any untoward medical occurrence in a participants or clinical trial participants administered a pharmaceutical product and which does not necessarily have a causal relationship with this treatment. The incidence and number of participants who experience an AE will be reported.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Participants are eligible to be included in the study only if they meet all of the following criteria:
- Male and female participants, 18 years of age and older.
- Body Mass Index (BMI) 18.5 and 40 kg/m2 and body weight at or below 120 kg.
- Baseline RHC performed during the Screening Period documenting:
- A minimum PVR of ≥ 5 Wood units (WU) or ≥ 400 dyn·sec·cm-5 and,
- A pulmonary artery wedge pressure (PAWP) of ≤ 15 mm Hg.
- Diagnosis of WHO pulmonary arterial hypertension (PAH) Group 1.
- Symptomatic PAH classified as WHO Functional class II to IV.
- On stable doses of at least 2 approved background PAH therapies and diuretics.
- 6-Minute Walk Distance (6MWD) ≥ 150 m and ≤ 500 m repeated twice during screening.
- Ability to adhere to study visit schedule and understand and comply with all protocol requirements.
Exclusion criteria
- PH WHO Groups 2, 3, 4 or 5.
- Hospitalization for any worsening medical condition or major surgery within 4 weeks prior to screening.
- Any symptomatic coronary disease events.
- History of heart transplant or on heart transplant list.
- Uncontrolled systemic hypertension.
- History of restrictive, constrictive or congestive cardiomyopathy.
- History of significant mitral regurgitation or aortic regurgitation valvular disease.
- Untreated or poorly controlled moderate or severe obstructive sleep apnea.
- A diagnosis of worse than moderate COPD or worse than mild ILD.
- Cerebrovascular event within 90 days prior to screening
- A pneumonectomy or lobectomy
- Having received an activin signaling inhibitor such as sotatercept at any time prior to screening
- A Hgb \> sex-specific ULN
- Platelets count \< 100,000/mm3
- Severe (stage ≥4) renal failure with eGFR \< 30 mL/min/m2
- Abnormally elevated liver function enzymes (ALT or AST \> 3X ULN, or total bilirubin \> 1.5X ULN).
Where
- Tampa, Florida
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Aug 17, 2026 · Source of record for eligibility and locations