A Randomized, Parallel-Group, Single-Attack, Open-Label Study to Evaluate the Efficacy of Diclofenac Potassium and Rimegepant for the Acute Treatment of Migraine (ATOM) (ATOM)

  • End date
    Dec 19, 2025
  • participants needed
  • sponsor
    Danish Headache Center
Updated on 19 October 2022
acute treatment
severe headache


In a real-world population of adults with migraine, the investigators would like to investigate whether 50 mg diclofenac potassium is non-inferior to 75 mg rimegepant in terms of pain freedom at 2 hours after drug intake.


The study design is a randomized, open-label, parallel-group, single-attack study with 50 mg diclofenac potassium and 75 mg rimegepant. 645 patients with migraine with or without aura according to the third edition of the International Classification of Headache Disorders (ICHD-3) will be included.

Each subject will randomly be allocated to one treatment, and given 42 days to treat a single qualifying migraine attack of moderate to severe intensity.

Condition Migraine With Aura, Migraine Without Aura
Treatment Rimegepant 75 MG, Diclofenac Potassium 50Mg/Pkt Oral Pwdr
Clinical Study IdentifierNCT05211154
SponsorDanish Headache Center
Last Modified on19 October 2022


Yes No Not Sure

Inclusion Criteria

Subject has provided informed consent prior to initiation of any study-specific activities/procedures
Aged 18 to 65 years upon entry into screening
History of migraine (with or without aura) for greater than or equal to 12 months before screening according to the ICHD-3 criteria based on medical records and/or patient self-report
Not more than 12 attacks per month with moderate to severe headache pain in each of the previous 3 months

Exclusion Criteria

Disease Related
Greater than 50 years of age at migraine onset
History of cluster headache or hemiplegic migraine headache
Inability to differentiate between migraine from other headaches
Has taken medication for acute treatment of headache (including acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), triptans, ergotamine, opioids, or combination analgesics) on 10 or more days per months in the previous 3 months
Has a history of migraine aura with diplopia or impairment of levels of consciousness, hemiplegic migraine, or retinal migraine
Required hospital treatment of a migraine attack 3 or more times in the previous 6 months
Other Medical Conditions
The subject is at risk of self-harm or harm to others as evidenced by past suicidal behavior
Has a chronic non-headache pain condition requiring daily pain medication
Has a history of any prior gastrointestinal conditions (e.g., diarrhea syndromes, inflammatory bowel disease) that may affect the absorption or metabolism of investigational product; participants with prior gastric bariatric interventions which have been reversed are not excluded
Has a history of malignancy in the prior 5 years, except for adequately treated basal cell or squamous cell skin cancer, or in situ cervical cancer
History or evidence of any other clinically significant disorder, condition or disease (except for those outlined above) that, in the opinion of the investigator would pose a risk to subject safety or interfere with the study evaluation, procedures or completion
Medication related
Start of new preventive migraine treatment within the last two months
Change in dosage of ongoing preventive migraine treatment within the last two months
Current treatment with monoclonal antibodies targeting calcitonin gene related piptide (CGRP) or CGRP receptors, or current use of small-molecule CGRP receptor antagonist (e.g. erenumab, fremanezumab, galcaneszumab or atogeptant)
Changes in treatment with selective serotonin reuptake inhibitors (SSRI) or serotonin norepinephrine reuptake inhibitors (SNRI) within the last two months
Use of the following medication within 30 days prior to screening
Strong and moderate cytochrome P450 3A4 (CYP3A4) inhibitors, including but not limited to systemic (oral/IV) itraconazole, ketoconazole, fluconazole; erythromycin, clarithromycin, telithromycin; diltiazem, verapamil; aprepitant; cyclosporine; nefazodone; cimetidine; quinine; and HIV protease inhibitors
Strong and moderate CYP3A4 inducers, including but not limited to barbiturates (eg, phenobarbital and primidone), systemic (oral/IV) glucocorticoids, nevirapine, efavirenz, pioglitazone, carbamazepine, phenytoin, rifampin, rifabutin, and St. John's wort
Inhibitors of the BCRP (breast cancer resistance protein) transporter (eg, rifampicin)
Drugs with narrow therapeutic margins (eg, digoxin, warfarin)
Other Exclusions
Female subjects of childbearing potential with a positive pregnancy test assessed at screening or day 1 by a urine pregnancy test
Female subject is pregnant or breastfeeding or planning to become pregnant or breastfeed during treatment and for an additional 16 weeks after the last dose of investigational product
Female subjects of childbearing potential unwilling to use 1 acceptable method of effective contraception during treatment and for an additional 16 weeks after the last dose of investigational product
Evidence of current pregnancy or breastfeeding per subject self-report or medical records
Subject has known sensitivity to any of the products or components to be administered during dosing
Subject likely to not be available to complete all protocol-required study visits or procedures, and/or to comply with all required study procedures (e.g, Clinical Outcome Assessments) to the best of the subject and investigator's knowledge
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