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Study of bosentan, prednisone and prednisolone in patients with newly diagnosed or relapsing giant cell arteritis

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 focuses on Giant Cell Arteritis, a condition that causes inflammation in blood vessels, typically affecting people over 50 years old. The study aims to evaluate whether adding bosentan treatment for three months helps patients who are already receiving standard therapy with corticosteroids (prednisone or prednisolone) for their condition.

The treatment involves taking bosentan tablets along with either prednisone or prednisolone tablets. The maximum daily dose of bosentan will be 250 mg, while the corticosteroid dose will be up to 40 mg per day. The treatment period with bosentan lasts for 16 weeks, while the corticosteroid treatment continues for up to 52 weeks.

During the study, doctors will monitor patients to see if they can reduce their corticosteroid dose according to a planned schedule while keeping their condition under control. They will also check for any new symptoms related to Giant Cell Arteritis and assess how well patients respond to the combined treatment. The study will track patients' progress for up to two years to understand the long-term effects of this treatment approach.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial treatment start

    You will start treatment with prednisone taken by mouth according to a specific dosing schedule

    You will be randomly assigned to one of two groups - either receiving bosentan or not receiving it in addition to prednisone

  2. Step 2

    First 3 months of treatment

    If assigned to the bosentan group, you will take this medication by mouth for 3 months

    You will continue taking prednisone according to the prescribed schedule

    Regular check-ups will monitor your condition and any potential side effects

  3. Step 3

    Ongoing monitoring - Week 26

    Your quality of life will be assessed using specific questionnaires

    Your response to treatment will be evaluated

    The dose of prednisone may be adjusted based on your condition

  4. Step 4

    52-week evaluation

    A comprehensive assessment of your condition will be performed

    Your prednisone dose will be reviewed

    Quality of life questionnaires will be completed again

    Any new health events will be documented

  5. Step 5

    Extended follow-up - Year 2

    Your condition will continue to be monitored

    The need for ongoing prednisone treatment will be evaluated

    Final assessment of treatment effectiveness will be performed

Who can join the trial?

8 criteria

  • Must be at least 50 years old when the disease started
  • Must have had a blood test showing either: - ESR (Erythrocyte Sedimentation Rate) of 50 or higher, or - CRP (C-Reactive Protein) of 20 or higher
  • Must have at least one of these symptoms: - New headaches - Scalp tenderness - Pain when chewing - Abnormal temporal artery - Vision problems - Muscle pain and stiffness in shoulders or hips
  • Must have either: - A positive temporal artery biopsy (a small tissue sample showing inflammation), or - Evidence of blood vessel inflammation on imaging tests (CT, MRI, or PET scan)
  • Must have active disease signs within 4 weeks before starting the study, including: - ESR of 30 or higher, or CRP of 10 or higher - At least one of the symptoms listed above
  • Must provide written consent to participate in the study
  • Must have social security coverage
  • For women: - Must be menopausal (no menstrual cycles for at least 2 years), or - If still having menstrual cycles, must use effective non-hormonal birth control and have a negative pregnancy test

Who cannot join the trial?

15 criteria

  • Age under 18 years old
  • Previous treatment with bosentan (a medication that widens blood vessels)
  • Known allergies or hypersensitivity to study medications
  • Active serious infections
  • Severe liver disease or abnormal liver function tests
  • Pregnancy or breastfeeding
  • Participation in another clinical trial within the last 30 days
  • Inability to follow study procedures or attend scheduled visits
  • Uncontrolled high blood pressure
  • History of heart failure
  • Active cancer or cancer treatment within the past 5 years
  • Severe kidney disease
  • Use of medications that could interact with study drugs
  • Mental conditions that could interfere with study participation
  • Drug or alcohol abuse within the past 6 months
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Investigated drugs

  • Bosentan

    is a medication that works by blocking specific receptors in blood vessels, helping them to relax and widen. In this trial, it is being studied as an additional treatment for patients with Giant Cell Arteritis (GCA), a condition that causes inflammation in blood vessels. The medication helps improve blood flow and may reduce the symptoms associated with GCA when used alongside glucocorticoid therapy.

  • Glucocorticoids

    (GC) are anti-inflammatory medications that help reduce inflammation in blood vessels. They are the standard treatment for Giant Cell Arteritis and work by suppressing the immune system's inflammatory response. These medications help manage symptoms such as headaches, scalp tenderness, and vision problems that are common in GCA.

What is already known about the treatment

Bosentan - An oral medication administered in tablet form that belongs to the class of endothelin receptor antagonists. It is primarily used in treating pulmonary arterial hypertension and is being investigated for potential benefits in Giant Cell Arteritis treatment. The medication works by blocking endothelin receptors, which helps prevent blood vessel constriction and reduces inflammation in blood vessel walls. Current clinical trials are exploring its effectiveness as an additional therapy alongside glucocorticoids for newly diagnosed or relapsing Giant Cell Arteritis, with particular interest in its potential to improve long-term treatment outcomes.

Investigated diseases

Giant-cell arteritis - A chronic inflammatory condition that affects large and medium-sized blood vessels, particularly those in the head and neck. The disease causes inflammation of the arteries' lining, leading to swelling and potential narrowing of affected blood vessels. It typically develops gradually, with common symptoms including headaches, scalp tenderness, jaw pain during chewing, and vision changes. The condition most commonly affects people over the age of 50, with women being more susceptible than men. The inflammation can cause the artery walls to become thick, stiff, and swollen.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-517030-17-00Protocol codeAPHP200041Estimated enrolment40 patientsSponsorAssistance Publique Hopitaux De Paris

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