Efficacy and Safety Study of Rimegepant for Migraine Prevention in Japanese Subjects (Japan Only)

Inclusion Criteria:

Subject has at least 1 year history of migraine (with or without aura) consistent with a diagnosis according to the International Classification of Headache Disorders, 3rd Edition, including the following:

1. Age of onset of migraines prior to 50 years of age.

2. Migraine attacks, on average, lasting 4 to 72 hours if untreated.

3. Per subject report, 4 to18 migraine attacks of moderate or severe intensity permonth within the last 3 months prior to the Screening Visit (month is defined as 4weeks for the purpose of this protocol).

4. 4 or more migraine days during Observation Period.

5. Not more than 18 headache days during the Observation Period.

6. Ability to distinguish migraine attacks from tension/cluster headaches.

7. Subjects on prophylactic migraine medication are permitted to remain on therapy ifthe dose has been stable for at least 3 months (12 weeks) prior to the ObservationPeriod, and the dose is not expected to change during the course of the study.

8. Subjects with contraindications for use of triptans may be included provided theymeet all other study entry criteria.

Exclusion Criteria:

1. Subject has a history of migraine with brainstem aura (basilar migraine), hemiplegicmigraine or retinal migraine.

2. Subjects with headaches occurring 19 or more days per month (migraine ornon-migraine) in any of the 3 months prior to the Screening Visit.

3. History of systemic use of analgesics (e.g. nonsteroidal anti-inflammatory drugs [NSAIDs] or acetaminophen) on ≥ 15 days per month during the 3 months (12 weeks)prior to the Screening Visit.

4. Subject with a history of HIV disease.

5. Subject history with current evidence of uncontrolled, unstable or recentlydiagnosed cardiovascular disease, such as ischemic heart disease, coronary arteryvasospasm, and cerebral ischemia. subjects with Myocardial Infarction (MI), AcuteCoronary Syndrome (ACS),Percutaneous Coronary Intervention (PCI), cardiac surgery,stroke or transient ischemic attack (TIA) during the 6 months prior to screening.

6. Uncontrolled hypertension, or uncontrolled diabetes (however subjects can beincluded who have stable hypertension and/or diabetes for 3 months prior toscreening).

7. Subject with other pain syndromes, psychiatric conditions, dementia, or significantneurological disorders (other than migraine) that, in the Investigator's opinion,might interfere with study assessments.

8. Subject has a history of gastric, or small intestinal surgery (including GastricBypass, Gastric Banding, Gastric Sleeve, Gastric Balloon, etc.), or has disease thatcauses malabsorption.

9. The subject has a history or current evidence of any unstable medical conditions (e.g., history of congenital heart disease or arrhythmia, known or suspectedinfection, hepatitis B or C, or cancer) that, in the investigator's opinion, wouldexpose them to undue risk of a significant adverse event (AE) or interfere withassessments of safety or efficacy during the course of the trial.

10. History of, treatment for, or evidence of, alcohol or drug abuse within the past 12months or subjects who have met DSM-V criteria for any significant substance usedisorder within the past 12 months from the date of the screening visit.

11. Participation in any other investigational clinical trial while participating inthis clinical trial.