Safety and Tolerability Study of Daily Dosing Rimegepant in Episodic Migraine Prevention

Key Inclusion Criteria:

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

• Age of onset of migraines prior to 50 years of age

• Migraine attacks, on average, lasting 4 -72 hours if untreated

• Per subject report, 4-14 migraine attacks per month within the last 3 months priorto the Screening Visit (month is defined as 4 weeks for the purpose of thisprotocol)

• Subjects ≥ 18 years

Key Exclusion Criteria:

• 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 (24 weeks) prior tothe Screening Visit.

• Uncontrolled hypertension (high blood pressure) or uncontrolled diabetes.

• 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 study

• History of use of opioid- or barbiturate- (e.g. butalbital) containing medicationfor 4 or more days per month during the 3 months (12 weeks) prior to the ScreeningVisit

• WOCBP who are unwilling or unable to use an acceptable contraceptive method orabstinence to avoid pregnancy for the entire study and for 28 days after the lastdose of study drug

• Women who are pregnant or breastfeeding

• Women with a positive pregnancy test at screening or prior to study drugadministration