Study of Oral Atogepant to Assess Adverse Events and Change in Disease Activity in Adult Participants With Menstrual Migraine

A migraine attack is a moderate or severe headache that usually occurs on one side of the head and is often throbbing or pulsating. The headache is often accompanied by sensitivity to light, sensitivity to sound, nausea, or other symptoms. Menstrual migraine (MM) attacks are migraine attacks that occur in individuals before or during their menstrual period. The main goals of the study are to evaluate the efficacy (how well the medicine works), safety, and tolerability (the degree to which any adverse symptoms can be handled by the patients during the study) of atogepant, compared to placebo (looks like the study treatment but has no medicine in it), for the prevention of MM.

Atogepant is an investigational drug being developed for the preventive treatment of menstrual migraine. Participants are randomly assigned to one of the 2 treatment groups called Arms to receive atogepant or matching placebo. There is 1 in a 2 chance for the participant to receive placebo. Approximately 430 adult female participants with menstrual migraine will be enrolled in approximately 85 sites across the world.

Participants will receive oral atogepant or matching placebo for 3 menstrual cycles during the double-blind period. During the open-label treatment period, participants will receive atogepant during each menstrual cycle.

There may be higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at a hospital or clinic. The safety and tolerability of the treatment will be checked by medical assessments, blood tests, checking for adverse events and completing questionnaires.


Eligibility Criteria:
Inclusion Criteria:

* History and eDiary confirmation have regular menstrual cycles within the range of 21 to 35 days in length (Note: menstrual cycle length is calculated as onset of menses until the day before the next onset of menses).
* History of migraine (with or without aura) according to the International Classification of Headache Disorders, 3rd Edition (ICHD-3) for \>= 12 months prior to Visit 1/Screening.
* Migraine onset before age 50 years.
* By history at Visit 1/Screening, participant meets ICHD-3 criteria for pure menstrual migraine with or without aura, or menstrually-related migraine with or without aura, i.e., in at least 2 out of 3 cycles, experiences migraine attacks starting during the PMP (Day -2 to Day +3 relative to menses onset) in the opinion of the investigator.
* Participant records 3 perimenstrual periods (PMP) in the eDiary during the screening period, and in at least 2 of 3 PMPs the participant experiences and records a migraine attack in the eDiary with at least 1 migraine day.

Exclusion Criteria:

* History of an average of 15 or more headache days per month during the 3 months prior to Visit 1/Screening per the investigator's judgment, or a current diagnosis of chronic migraine as defined by International Classification of Headache Disorders, 3rd Edition (ICHD-3).
* An average of 15 or more headache days per month recorded in the eDiary during the screening period.
* History of migraine with brainstem aura, hemiplegic migraine, or retinal migraine as defined by ICHD-3.
* Current diagnosis of new persistent daily headache, trigeminal autonomic cephalalgia (e.g., cluster headache), or painful cranial neuropathy as defined by ICHD-3.
* Required hospital/emergency room treatment for migraine attacks 3 or more times within 6 months prior to Visit 1/Screening.
* Presence of other confounding pain syndromes, confounding psychiatric conditions, dementia, epilepsy, or significant neurological disorders other than migraine per investigator judgment.
* Has a condition or situation, which the investigator feels will compromise the safety of the participant or the quality of the data and renders the subject an unsuitable candidate for the study.