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Study on the Effects of Bosentan on Blood Pressure in Patients with Uncontrolled Hypertension

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the effects of a medication called bosentan on patients with uncontrolled arterial hypertension, which is a condition where blood pressure remains high despite treatment. The study aims to understand how blocking a specific receptor in the body, known as the endothelin-1 receptor, can impact blood vessels and kidney function in these patients.

Participants in the study will receive bosentan in the form of film-coated tablets, taken orally. The study will compare the effects of two different doses of bosentan (62.5 mg and 125 mg) over a period of eight weeks. Some participants may receive a placebo, which is a tablet that looks like the medication but does not contain the active ingredient. The main goal is to observe changes in the function of the blood vessels, particularly how they dilate or widen, which is important for controlling blood pressure.

Throughout the study, researchers will monitor changes in blood pressure, the stiffness of the arteries, and certain substances in the blood that are related to blood flow and kidney function. This research is important for finding better ways to manage high blood pressure that does not respond well to standard treatments.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, eligibility is confirmed based on specific criteria such as age between 30 and 80 years, and a diagnosis of uncontrolled arterial hypertension.

    Participants must have a hemoglobin level greater than 11 g/dL and, if applicable, use reliable contraception methods.

  2. Step 2

    Medication administration

    Participants will receive bosentan, an oral medication available in two dosages: 62.5 mg and 125 mg, in the form of film-coated tablets.

    The medication is administered to assess its impact on endothelial function over an 8-week period.

  3. Step 3

    Monitoring and assessments

    Throughout the 8-week period, changes in the dilation of the radial artery and blood flow will be monitored.

    Additional assessments include changes in peripheral and central arterial pressures, arterial stiffness, and local concentrations of certain substances in the blood.

  4. Step 4

    Completion of the study

    At the end of the 8-week period, the study will evaluate the primary and secondary endpoints, including the change in arterial function and other health indicators.

    The study is estimated to conclude by April 20, 2025.

Who can join the trial?

8 criteria

  • Age between 30 and 80 years old.
  • Patients with uncontrolled hypertension, which means high blood pressure that is not well-managed. This is defined as blood pressure greater than or equal to 140/90 mm Hg when measured in a medical clinic.
  • Patients with uncontrolled hypertension confirmed by self-measurement (average of 135/85 mmHg or higher) or by ambulatory blood pressure measurement (average over 24 hours of 130/80 mmHg or higher).
  • Hemoglobin level greater than 11 g/dL. Hemoglobin is a protein in your blood that carries oxygen.
  • For women who can have children, reliable methods of birth control should be used. Hormonal birth control should not be the only method used during the treatment.
  • For postmenopausal women, a confirmatory diagnosis is needed. This means no medically induced absence of periods for at least 12 months and being older than 45 years before joining the study.
  • Patient must have read and understood the information provided and signed the consent form.
  • Patient must be affiliated with a social security scheme.

Who cannot join the trial?

1 criterion

  • Having uncontrolled arterial hypertension, which means high blood pressure that is not well-managed with treatment.
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Investigated drugs

ET-1 Receptor Antagonist is a medication being studied for its potential to improve the function of blood vessels in patients with high blood pressure that is not well controlled. This medication works by blocking the action of endothelin-1, a substance in the body that can cause blood vessels to narrow. By preventing this narrowing, the medication may help to lower blood pressure and improve overall heart and kidney health. The study aims to observe these effects over an 8-week period.

What is already known about the treatment

Endothelin-1 Receptor Antagonist – This medication is administered orally and is currently being studied for its effects on patients with uncontrolled arterial hypertension. It is in the clinical trial phase, focusing on its impact on vascular and renal functions. The main therapeutic indication is to manage high blood pressure that is not controlled by other treatments. At the molecular level, it works by blocking the endothelin-1 receptors, which are involved in the constriction of blood vessels, thereby helping to lower blood pressure. It is classified as an endothelin receptor antagonist in pharmacology.

Investigated diseases

Uncontrolled Arterial Hypertension – This condition is characterized by consistently high blood pressure that remains above the target level despite the use of multiple antihypertensive medications. It occurs when the force of the blood against the artery walls is too high, which can lead to damage over time. The progression of this disease can result in increased workload on the heart and blood vessels, potentially leading to complications such as heart disease or stroke. Patients may experience symptoms like headaches, shortness of breath, or nosebleeds, although many individuals may not have noticeable symptoms. The condition requires careful management to prevent further health issues and maintain cardiovascular health.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-515928-36-00Protocol code2018/0350/HPEstimated enrolment24 patientsSponsorCentre Hospitalier Universitaire Rouen

sourced from the EU Clinical Trials Register and site verification

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).