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 of Headache 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 prior to the Screening Visit (month is defined as 4 weeks for the purpose of this protocol) * Subjects ≥ 18 years Key Exclusion Criteria: * Subject history with current evidence of uncontrolled, unstable or recently diagnosed cardiovascular disease, such as ischemic heart disease, coronary artery vasospasm, and cerebral ischemia. Subjects with myocardial infarction (MI), acute coronary syndrome (ACS), percutaneous coronary intervention (PCI), cardiac surgery, stroke or transient ischemic attack (TIA) during the 6 months (24 weeks) prior to the 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 suspected infection, hepatitis B or C, or cancer) that, in the investigator's opinion, would expose them to undue risk of a significant adverse event (AE) or interfere with assessments of safety or efficacy during the course of the study * History of use of opioid- …