Study of gallium-68 FAPI imaging to assess blood vessel changes in patients with pulmonary arterial hypertension receiving sotatercept

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What is this study about?

This study is looking at pulmonary arterial hypertension, which is a condition where the blood pressure in the arteries that carry blood from the heart to the lungs becomes too high. This causes the heart to work harder and can lead to changes in these blood vessels and the right side of the heart. The study will use two imaging substances called [68Ga]Ga-FAPI and [68Ga]Ga-MAA that are given through a vein to take special pictures of the lungs and heart. These substances help doctors see changes in the blood vessels and how blood flows through the lungs. The study will also involve treatment with a medication called Winrevair, which contains sotatercept and is given as an injection under the skin.

The purpose of the study is to see whether imaging with [68Ga]Ga-FAPI can help doctors see changes in the blood vessels of the lungs in people with pulmonary arterial hypertension without needing invasive procedures. The study will look at whether this imaging method can show these changes and whether the changes can be seen after treatment with sotatercept. The study will also look at how the imaging results relate to other measurements of how well the heart and lungs are working, such as exercise ability and blood test results.

People in the study will have imaging scans at the beginning and then again after receiving treatment with sotatercept. The imaging will include scans using both [68Ga]Ga-FAPI and [68Ga]Ga-MAA to look at different aspects of the blood vessels and blood flow in the lungs. The study will also measure how well the right side of the heart is working and compare the imaging results with other tests that are commonly used to check pulmonary arterial hypertension, including heart function tests, walking tests, and blood tests. The entire study is expected to last until March 2027.

1 Initial assessment and baseline imaging

At the beginning of the study, your baseline condition will be documented. This includes a recent right heart catheterization, which is a procedure that measures pressures in the heart and lungs using a thin tube inserted into a vein.

You will undergo a PET/CT scan with [68Ga]Ga-FAPI, which is an imaging test that uses a small amount of radioactive tracer given through a vein to take detailed pictures of your lungs and heart. This scan helps assess changes in the blood vessels of your lungs.

You will also receive a lung perfusion scan using [68Ga]Ga-MAA, another radioactive tracer given through a vein. This scan shows how blood flows through your lungs.

Additional assessments will include a 6-minute walking test, which measures how far you can walk in six minutes, and an echocardiogram, which is an ultrasound of your heart to check its function.

Blood tests will be performed to measure NT-proBNP, a substance that indicates how well your heart is working.

You will be asked to complete a quality of life questionnaire called EMPHASIS-10 to assess how your condition affects your daily life.

Your symptoms will be classified according to the WHO functional class, which describes how much your condition limits your physical activities.

2 Starting treatment with sotatercept

You will begin treatment with sotatercept, which is given as an injection under the skin. The dosage will be either 45 mg or 60 mg.

This medication is administered in addition to your current background therapy for pulmonary arterial hypertension.

The treatment will continue throughout the study period.

3 Follow-up assessment during treatment

During your treatment with sotatercept, you will have a follow-up visit for repeat assessments.

You will undergo another PET/CT scan with [68Ga]Ga-FAPI to evaluate changes in your lung blood vessels and heart.

A second lung perfusion scan with [68Ga]Ga-MAA will be performed to reassess blood flow in your lungs.

The same clinical assessments from the initial visit will be repeated, including the 6-minute walking test, blood tests for NT-proBNP, and the EMPHASIS-10 quality of life questionnaire.

Your WHO functional class will be reassessed to monitor any changes in your symptoms.

4 Final assessment after 24 weeks of treatment

After 24 weeks of treatment with sotatercept, you will have a final study visit.

You will undergo a third PET/CT scan with [68Ga]Ga-FAPI and a third lung perfusion scan with [68Ga]Ga-MAA.

All clinical assessments will be repeated once more, including the 6-minute walking test, blood tests for NT-proBNP, echocardiogram, and the EMPHASIS-10 questionnaire.

Your WHO functional class will be evaluated again to determine any improvement or changes in your condition.

These final scans and tests will help determine whether the imaging technique can detect improvements in your lung blood vessels and heart function after treatment.

Who Can Join the Study?

You must be 18 years old or older
You must have had a right heart catheterization (a procedure where a thin tube is inserted into your heart through a blood vessel to measure pressures) within the last 12 months that showed specific measurements: a PVR (pulmonary vascular resistance, which measures how hard it is for blood to flow through your lung arteries) of 4 Wood units or higher, and a PCWP (pulmonary capillary wedge pressure, which measures pressure in your lung blood vessels) or LVEDP (left ventricular end-diastolic pressure, which measures pressure in your heart’s main pumping chamber) of 15 mmHg or lower
You must have been diagnosed with WHO PAH Group 1 (a specific classification of pulmonary arterial hypertension), which includes one of these types: idiopathic PAH (high blood pressure in lung arteries with no known cause), heritable PAH (high blood pressure in lung arteries that runs in families), drug or toxin-induced PAH (high blood pressure in lung arteries caused by certain medications or toxic substances), PAH associated with connective tissue disease (high blood pressure in lung arteries linked to diseases affecting tissues that support your body), or PAH associated with simple congenital systemic-to-pulmonary shunts (high blood pressure in lung arteries related to a heart defect present from birth that was repaired at least 1 year ago)
You must be currently taking two or three background therapies (medications to treat your pulmonary arterial hypertension)
You must have symptoms classified as WHO FC II or III (World Health Organization Functional Class II or III, which means you have slight to marked limitation in physical activity due to your condition)
You will be starting treatment with Sotatercept (a medication for pulmonary arterial hypertension)
You must be able to attend all scheduled study visits and follow all study requirements
You must be able to understand the study and provide written permission to participate

Who Cannot Join the Study?

There are no specific exclusion criteria listed for this clinical trial

Where you can join this trial?

Verified and Recommended Sites

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Verified Sites

Site Name	City	Country	Status
Centre Hospitalier Regional Et Universitaire De Brest	Brest	France

Other Sites

No sites found in this category

Trial status

Country	Status	Recruitment Start
France	Not yet recruiting	15.08.2025

Trial locations

Investigated drugs:

68Ga-FAPI is a radioactive tracer used during a special imaging scan called PET/CT. This substance is injected into your body and helps doctors take detailed pictures to see changes in the blood vessels of your lungs and heart. It works by attaching to certain cells involved in tissue remodeling, allowing doctors to better understand how pulmonary arterial hypertension affects your heart and lungs.

Investigated diseases:

Pulmonary arterial hypertension

Pulmonary Arterial Hypertension – Pulmonary arterial hypertension is a condition where the blood pressure in the arteries of the lungs becomes abnormally high. The small blood vessels in the lungs become narrowed, blocked, or damaged over time. This makes it harder for blood to flow through the lungs, which forces the heart to work harder to pump blood. As the condition progresses, the right side of the heart becomes strained and weakened from the extra effort. The narrowing of the lung arteries happens because the walls of these vessels become thick and stiff. Eventually, the heart’s ability to pump blood effectively decreases, leading to reduced oxygen delivery throughout the body.

Trial ID:

2025-520731-17-02

Protocol code:

29BRC24.0296

Trial Phase:

Therapeutic confirmatory (Phase III)

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Study of gallium-68 FAPI imaging to assess blood vessel changes in patients with pulmonary arterial hypertension receiving sotatercept

What is this study about?

Who Can Join the Study?

Who Cannot Join the Study?