Clinical trial Recruiting at 1 site Phase 2 Interventional Ages 18 to 80

Blocking endothelin-1 receptors to treat resistant high blood pressure

Official title: VASCULAR AND RENAL IMPACT OF ENDOTHELIN-1 RECEPTOR BLOCKADE IN PATIENTS WITH RESISTANT ARTERIAL HYPERTENSION

Run by University Hospital, Rouen · NCT04388124 · Data updated 2026-11-12

This tests whether adding bosentan, an endothelin-1 receptor blocker, helps lower blood pressure and improve blood vessel function in adults whose blood pressure stays high despite three medications.

More Resistant Hypertension trials

Quick facts

PhasePhase 2
Study typeInterventional
Ages18 Years to 80 Years
SexAll
Enrollment24 (estimated)
SponsorUniversity Hospital, Rouen
Academic / other
Locations1 site (Rouen)
StatusRecruiting
StartedOctober 20, 2021
Main results expectedAugust 2026
Study endsAugust 2026
Registry record updatedFebruary 17, 2026
Trial IDNCT04388124 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Adults 30–80 years old with resistant hypertension defined by SFHTA criteria (BP ≥140/90 mmHg on triple therapy including a diuretic, confirmed by home or 24‑hour readings) with hemoglobin ≥12 g/dL and reliable contraception for women of childbearing potential.

Probably not a fit

Patients with well‑controlled blood pressure, significant anemia, pregnancy or inadequate contraception, known liver disease, or other contraindications to bosentan are unlikely to receive benefit from this intervention.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This Phase 2 interventional study enrolls adults aged 30–80 with resistant hypertension despite optimal triple antihypertensive therapy including a diuretic. Participants receive bosentan or placebo and undergo measures of vascular function, systemic and central hemodynamics, and renal safety monitoring. The trial focuses on both blood pressure effects and endothelial function to understand vascular impact in this high‑risk group. Safety assessments include hemoglobin and renal monitoring given known drug risks.

Why it matters

Potential benefit: If successful, adding an endothelin-1 receptor blocker could improve blood pressure control and vascular (endothelial) function in patients with resistant hypertension.

How similar studies have gone: Endothelin receptor antagonists have proven benefits in pulmonary hypertension and some small trials and pilot data suggest blood pressure and vascular effects in resistant systemic hypertension, but large-scale evidence in this indication is limited.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion Criteria:

* age between 30 and 80 years old
* Patients with resistant hypertension defined according to the criteria recognized by the French Society of Hypertension (SFHTA): arterial pressure greater than or equal to 140 and / 90 mm Hg under triple antihypertensive therapy at optimal dose comprising at least one diuretic pendant at less than 4 weeks.
* Patients with resistant hypertension confirmed by self-measurement (≥135 / 85 mmHg on average) or by ambulatory blood pressure measurement (mean of 24h ≥130 / 80 mmHg).
* Hemoglobin level ≥ 12 g / dL
* For women of childbearing potential, reliable methods of contraception (as defined by the WHO-Pearl Index) should be used (hormonal contraception should not be the only contraceptive method used during bosentan treatment).
* For postmenopausal women: confirmatory diagnosis (non-medically induced amenorrhea for at least 12 months and age greater than 45, before the inclusion visit)
* Patient who read and understood the newsletter and signed the consent form
* Patient affiliated to a social security scheme

Exclusion Criteria:

* Patients with hypertension
* Patients with secondary arterial hypertension other than sleep apnea syndrome or chronic renal failure stage 2 or 3.
* Patients with hypertension greater than or equal to 180 and / or 110mmHg
* Chronic renal failure stage 4 and 5 (defined by DFG CKD-EPI \<30 ml / min / 1,73m²)
* Renal transplant patient XML File Identifier: CEyMau8sPo+QFyOLD1ZEY3ZGFow= Page 11/22
* Orthostatic hypotension (decreased SBP\> 20mmHg and / or DBP\> 10mmHg occurring within 3 minutes of standing).
* Contra-indication to NATISPRAY 0.30 mg / dose, oral spray solution (including nitrate hypersensitivity) in accordance with the NATISPRAY

SPC:

* shock, severe hypotension,
* in combination with sildenafil
* obstructive cardiomyopathy,
* inferior court inferior myocardial infarction with right ventricular extension, except in case of evidence of left ventricular failure,
* intracranial hypertension,

  • Contra-indication to BOSENTAN MYLAN 62.5 mg and 125 mg filmcoated tablets:
* Hypersensitivity to the active substance or to any of the excipients listed in the SPC Moderate to severe hepatic insufficiency corresponding to class B or C of the Child-Pugh classification
* Serum levels of liver aminotransferases, ASAT and / or ALAT\> 3 times the upper limit of normal at start of treatment (results less than 3 months old).
* Association with ciclosporin A

  * Known allergy to cellulose
  * Patients treated with: tacrolimus or sirolimus, fluconazole or other CYP2C9 or CYP3A4 inhibitors, glibenclamide, rifampicin, antiretroviral drugs including lopinavir + ritonavir, warfarin, simvastatin, ketoconazole, epoprostenol, sildenafil and digoxin
  * Pregnant, breastfeeding woman, or woman of childbearing potential not using reliable methods of contraception (hormonal contraception should not be the only contraceptive method used during bosentan treatment) or no proven reliable effective contraception;
  * Person deprived of liberty by an administrative or judicial decision or person placed under the protection of justice, under tutorship or curatorship
  * Patient participating or having participated in the 4 weeks prior to inclusion in a clinical trial

Where it's running

  • Chu Rouen
    Rouen, France
    Recruiting

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.