Reverse Remodeling of the Pulmonary Vasculature: a Longitudinal, Investigational Study of the Effects of Sotatercept.

The goal of this study is to learn more about how sotatercept works and if it helps the lung arteries become healthier. Sotatercept will be associated with the following:

1. Improvement in capillary blush, reduce the tapering and tortuosity of affected vessels on pulmonary wedge angiography and decreased wall thickness on intravascular ultrasound in previously affected areas.
2. Improvement in previously poorly or non-perfused areas rather than increased perfusion to previously perfused areas.
3. No changes in baseline ventilation and improvement and ventilation/perfusion matching.

Study Overview

• Status: Not yet recruiting
• Conditions: Pulmonary Hypertension; Pulmonary Arterial Hypertension (PAH)

• Study Type: Observational
• Enrollment (Estimated): 30

Contacts and Locations

• Study Contact: Name: The clinical and translational sciences research center; Phone Number: (520) 626-8000; Email: esmeralda97h@arizona.edu
• Study Contact Backup: Name: Study Coordinator; Phone Number: (520) 626-4804; Email: esmeralda97h@arizona.edu

Study Locations

• United States
  • Arizona
    • Tucson, Arizona, United States, 85724
      • The Clinical and Translational Sciences Research Center
      • Contact: Esme Study Coordinator; Phone Number: (520) 626-4804; Email: esmeralda97h@arizona.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Non-healthy adults with Group 1 Pulmonary Hypertension

Description

Inclusion Criteria - Feasibility Group:

• Group 1 Pulmonary Hypertension (G1PH)-must be idiopathic, drug induced, or hereditary (D/H/I)
• Age < 65 years at time of diagnosis
• Must be 18 years of age or older

Inclusion Criteria - "Real-world" treatment naïve cohort:

• Group 1 Pulmonary Hypertension (G1PH)-all types
• Must be treatment naïve
• Must be 18 years of age or older

Inclusion Criteria - "Real-world" prevalent cohort:

• Group 1 Pulmonary Hypertension (G1PH)-all types
• Must be 18 years of age or older

Exclusion Criteria:

• Contraindication to right heart catheterization (per PI)
• Prior exposure to sotatercept
• Hemoglobin > 18 g/dL at screening
• Estimated GFR < 30 mL/min at screening
• Platelet count <30 at screening
• Positive pregnancy test

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort
Feasibility Group; The feasibility group will consist of 10 participants with Group 1 Pulmonary Hypertension (idiopathic, drug induced, or hereditary) to be enrolled in the first phase of the study.
Real World Cohort - Treatment Naïve Cohort; This cohort will consist of 10 participants with Group 1 Pulmonary Hypertension (all types), treatment naïve, to be enrolled in the second phase of the study.
Real World Cohort - Prevalent Cohort; This cohort will consist of 10 participants with Group 1 Pulmonary Hypertension (all types) to be enrolled in the second phase of the study.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To assess the reverse remodeling of previously affected vascular structures by using intravascular ultrasound at Baseline, 3 month, 6 month or 9 month.	This is a medical imaging technique to see inside blood the vessels, especially the arteries around the heart. A catheter with an ultrasound probe at the tip of it will be inserted into a blood vessel and guided to the area that needs to be examined and images of the inside of the vessel will be obtained.	At Baseline and 6 month Evaluation for phase 1 feasibility group and Phase 2 prevalent group. At Baseline, 3 month evaluation and 9 month Evaluation for phase 2 treatment-naive group.
To assess the reverse remodeling of previously affected vascular structures by using pulmonary wedge angiography at Baseline, 3 month, 6 month or 9 month.	The pulmonary wedge angiography will look at the blood vessels in the lungs to see how blood flows. A catheter is inserted into a vein and it is moved carefully until it reaches the pulmonary artery and temporarily blocks that small vessel. A contrast dye will be injected through the catheter making the blood vessels visible on x-ray images. Several images are captured with the dye (contrast), called an angiogram.	At Baseline and 6 month Evaluation for phase 1 feasibility group and Phase 2 prevalent group. At Baseline, 3 month evaluation and 9 month Evaluation for phase 2 treatment-naive group.
To examine the longitudinal effects of sotatercept on ventilation perfusion matching with Ventilation/perfusion single photon emission computed tomography (V/Q SPECT)	During the V/Q SPECT, participants will breathe in small amounts of radioactive tracers and will receive an injection of another tracer into your vein that flows with your blood into your lungs. The special camera takes pictures of the tracers to see where air and blood flow in your lungs.	At Baseline and 6 month Evaluation for phase 1 feasibility group and Phase 2 prevalent group. At Baseline, 3 month evaluation and 9 month Evaluation for phase 2 treatment-naive group.

Collaborators and Investigators

• Sponsor: Franz Rischard, DO
• Collaborators: Acceleron Pharma, Inc., a wholly-owned subsidiary of Merck & Co., Inc., Rahway, NJ USA
• Investigators: Principal Investigator: Franz Rischard, MD, University of Arizona

Study record dates

Study Major Dates

• Study Start (Estimated): March 15, 2026
• Primary Completion (Estimated): March 15, 2028
• Study Completion (Estimated): June 15, 2028

Study Registration Dates

• First Submitted: March 2, 2026
• First Submitted That Met QC Criteria: March 17, 2026
• First Posted (Actual): March 23, 2026

Study Record Updates

• Last Update Posted (Actual): March 23, 2026
• Last Update Submitted That Met QC Criteria: March 17, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Respiratory Tract Diseases; Lung Diseases; Hypertension; Pulmonary Arterial Hypertension; Hypertension, Pulmonary
• Other Study ID Numbers: 00006475

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No