Pulmonary arterial hypertension is a rare disease where the small arteries in the lungs narrow and stiffen, forcing the heart to work harder to pump blood through them. About 500 to 1,000 people are diagnosed each year in the United States. Treatment now includes pills, inhaled drugs, and IV or subcutaneous infusions that relax lung blood vessels and slow disease progression.
What's actually going on in research
Trials are testing sotatercept, a drug that targets disease biology rather than just dilating vessels, along with combinations of existing therapies and newer oral prostacyclin-pathway drugs. Researchers are also studying earlier treatment in less severe disease, long-acting formulations that reduce infusion burden, and biomarkers that predict who will respond to specific drugs.
Sotatercept
This twice-monthly injection targets the underlying imbalance in cell growth that causes vessel narrowing. FDA approved it in 2024 for PAH, the first new mechanism in over a decade.
Combination therapy
Studies are testing whether starting multiple drug classes at once — rather than adding them one at a time — can keep people stable longer. Early trials suggest upfront combinations may slow disease better than traditional stepwise approaches.
Less-frequent dosing
New formulations aim to reduce the burden of continuous IV infusions. Trials are testing weekly or less-frequent subcutaneous versions of treprostinil and other prostacyclin-pathway drugs.
What to know before you search
Eligibility often depends on PAH severity (measured by walk distance and heart function tests), PAH subtype, and which drugs you've already tried.
What types of trials are currently open
- Treatment trials — Testing new oral, inhaled, or injected drugs — or combinations of existing drugs — to see if they improve exercise capacity and slow disease progression.
- Early intervention trials — Studies in people with less severe PAH, testing whether starting treatment earlier prevents worsening.
- Formulation trials — Testing new ways to deliver existing drugs, like patches or weekly injections, to reduce treatment burden.
- Observational registries — Following people with PAH over years to understand disease patterns, treatment responses, and long-term outcomes.
Recently added Pulmonary Arterial Hypertension trials
Randomized Study of Triple Therapy vs Sildenafil Dose Optimization in Pulmonary Arterial Hypertension
Pulmonary arterial hypertension (PAH) is a rare and progressive disease characterized by increased pressure in the pulmonary arteries, leading to right heart failure and premature death. Although combination therapy has improved outcomes, many patients remain at intermediate or high clinical risk despite treatment. When patients do not reach low-risk status, treatment escalation is recommended. However, different escalation strategies are used in clinical practice, including increasing the dose of existing medications or adding a third drug that targets a different biological pathway. There is limited prospective randomized evidence directly comparing these approaches. The ASCEND-PAH study is a prospective, randomized, open-label clinical trial designed to compare two therapeutic escalation strategies in adults with PAH who remain at intermediate or high risk despite dual therapy with an endothelin receptor antagonist and sildenafil. Participants will be randomized to either: (1) escalation to triple therapy with the addition of a prostacyclin pathway agent, or (2) optimization of dual therapy by increasing the dose of sildenafil. The primary objective is to compare the proportion of patients who improve their risk category according to the COMPERA 2.0 four-stratum risk model within 3 to 6 months after randomization. Secondary outcomes include changes in functional status, exercise capacity, biomarkers, clinical worsening, safety, and treatment persistence
Multimodality RV Phenotyping for Risk Stratification and Short-Term Outcomes in Group 1 PAH
The MIRROR-PAH is a single-center, prospective, observational cohort study evaluating the incremental value of multimodality imaging-derived right ventricular characteristics for risk stratification in patients with Group 1 pulmonary arterial hypertension (PAH). The study aims to determine whether incorporation of echocardiographic and cardiac magnetic resonance (CMR)-derived right ventricular parameters into established non-invasive risk assessment models results in risk reclassification and improves identification of patients at risk for short-term clinical worsening. Adult patients with established Group 1 PAH undergoing routine follow-up and with available right heart catheterization (RHC) and CMR data will be consecutively enrolled. Clinical, laboratory, echocardiographic, and follow-up data will be prospectively collected over a 6-month period. Associations between multimodality imaging findings, invasive hemodynamic measurements, risk classification, and short-term clinical outcomes will be evaluated.
Find Pulmonary Arterial Hypertension trials matched specifically to you
Answer 3 quick questions and we'll show you trials that fit your situation.