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Chronic CandClus2: A randomized, placebo-controlled, triple blind crossover study of candesartan in adults with chronic cluster headache
EU CTIS ID: 2025-521529-34-00
What this study is testing
The main objective of this study is to assess the prophylactic efficacy of the angiotensin-receptor antagonist candesartan 32 mg compared with placebo in reducing the frequency of severe and very severe cluster headache attacks in participants with chronic cluster headache during two four-week blinded periods compared with a two-week baseline (pre-randomization diary phase).
- Therapeutic confirmatory (Phase III)
A plain-language read of the study's public EU CTIS listing. The study team confirms the details.
Who can take part
You may be able to join if
- Participant must be 18 to 70 years of age inclusive, at the time of signing the informed consent
- Participants who have chronic cluster headache according to ICHD-3 criteria present at inclusion
- Participants must have had chronic cluster headache for > 1 year and usual cluster headache periods should last > 5 weeks
- Participants that if they have other ongoing concomitant infrequent primary headache types, such as episodic migraine or episodic tension-type headache, can clearly differentiate them from attacks of CH based on the quality of pain and associated symptoms
- Participants must experience between 4 attacks per week and a maximum of 8 attacks per day of severe or very severe intensity on average over the two-week baseline period
- The cluster headache at the time of inclusion and baseline should exhibit characteristics consistent with the participant's typical symptoms
You likely can't join if
- ECH excludes the participant from the study
- Any history of severe renal insufficiency
- Hypersensitivity to candesartan, placebo or any of the excipients
- Severe hepatic impairment and/or cholestasis
- Current or recent (within last 12 months) treatment with candesartan for any indication
- Current use of other antihypertensive medication(s) including verapamil and metoprolol (see section 6.9)
See the full eligibility criteria
Who can join
- Participant must be 18 to 70 years of age inclusive, at the time of signing the informed consent
- Participants who have chronic cluster headache according to ICHD-3 criteria present at inclusion
- Participants must have had chronic cluster headache for > 1 year and usual cluster headache periods should last > 5 weeks
- Participants that if they have other ongoing concomitant infrequent primary headache types, such as episodic migraine or episodic tension-type headache, can clearly differentiate them from attacks of CH based on the quality of pain and associated symptoms
- Participants must experience between 4 attacks per week and a maximum of 8 attacks per day of severe or very severe intensity on average over the two-week baseline period
- The cluster headache at the time of inclusion and baseline should exhibit characteristics consistent with the participant's typical symptoms
- Contraceptive use by women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies: No contraceptive/barrier requirements needed for male participants; For women of childbearing potential (WOCBP), it is required that there be no ongoing pregnancy or planned pregnancies during the study period. The use of a contraception method as listed in section 10.4.2 in the protocol is mandatory.
- Capable of giving signed informed consent as described in Appendix 1 which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol
What rules you out
- ECH excludes the participant from the study
- Any history of severe renal insufficiency
- Hypersensitivity to candesartan, placebo or any of the excipients
- Severe hepatic impairment and/or cholestasis
- Current or recent (within last 12 months) treatment with candesartan for any indication
- Current use of other antihypertensive medication(s) including verapamil and metoprolol (see section 6.9)
- Recent initiation or change in dose (<4 months) of preventive CH medication with galcanezumab or other parenteral CGRP-inhibitors, or botulinum toxin (<6 months, fewer than 3 treatment sessions). Stable dosage with CGRP-inhibitors > 4 months and/or botulinum toxin > 6 months (at least 3 treatment sessions) is allowed
- Treatment with greater occipital nerve blocks containing steroids or oral/parental prednisone/prednisolone < 4 weeks
- Recent initiation (< 4 weeks) of oral preventive CH medications including indomethacin or oral gepants (preventive use)
- Current use of potassium supplements
- Current use of spironolactone
- CH due to known structural lesion
- Current use of Lithium
- Current or recent (< 4 weeks) participation in other relevant clinical studies
- CCH, but with shorter bouts lasting <5 weeks with attack free periods <3 months should be excluded
- Abuse of alcohol or illicit drugs
- Women of child-bearing age without contraception
- Inability to understand study procedures and to comply with them for the entire length of the study
- Any previous surgical treatment for CH like deep brain stimulation, microvascular decompression, gamma knife radiosurgery, neurostimulation or other invasive treatments
- Current chronic migraine or chronic tension-type headache (migraine or tension-type headache that has met the ICHD-3 criteria for these conditions within the past 12 months)
- Pregnancy, planning to get pregnant, inability to use contraceptives (See inclusion criteria, number 7), and lactating
- Severe depression or other psychiatric disorder that may interfere with the treatment
- Other severe chronic pain conditions that may interfere with the study, including trigeminal neuralgia
- History of angioneurotic edema due to candesartan or other antihypertensive medication(s)
- Primary hyperaldosteronism (Conn’s syndrome))
The study team makes the final eligibility decision.
Questions & answers
Do participants get paid in this trial?
This listing doesn't specify compensation. Many trials still reimburse travel or offer a stipend, so it's worth asking the study team when you connect.
Is it free to join, and do I need insurance?
Searching and applying through BridgeMD is free. In clinical trials the study-related treatment and visits are generally provided at no cost to you. You usually don't need insurance to take part - confirm specifics with the study team.
How long does this study last?
The listing doesn't state an exact length. The study team walks you through the schedule and number of visits before you decide to enroll.
Who can join this trial?
This study is enrolling all sexes, 65+ years, 18-64 years. The study team makes the final eligibility decision.
Explore other conditions
BridgeMD is an information and trial-matching tool - not medical advice, and not the study sponsor. Details come from EU CTIS; the study team decides eligibility.