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

Prior treatment

• Subjects with headaches occurring 19 or more days per month (migraine or non-migraine) in any of the 3 months prior to the Screening Visit.
• 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.
• 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 prior to screening.
• Uncontrolled hypertension, or uncontrolled diabetes (however subjects can be included who have stable hypertension and/or diabetes for 3 months prior to screening).

Other illness

• Subject has a history of migraine with brainstem aura (basilar migraine), hemiplegic migraine or retinal migraine.
• Subject with a history of HIV disease.
• Subject with other pain syndromes, psychiatric conditions, dementia, or significant neurological disorders (other than migraine) that, in the Investigator's opinion, might interfere with study assessments.
• Subject has a history of gastric, or small intestinal surgery (including Gastric Bypass, Gastric Banding, Gastric Sleeve, Gastric Balloon, etc.), or has disease that causes malabsorption.
• 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 trial.
• History of, treatment for, or evidence of, alcohol or drug abuse within the past 12 months or subjects who have met DSM-V criteria for any significant substance use disorder within the past 12 months from the date of the screening visit.

Other

• Participation in any other investigational clinical trial while participating in this clinical trial.

• 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:
• Age of onset of migraines prior to 50 years of age.
• Migraine attacks, on average, lasting 4 to 72 hours if untreated.
• Per subject report, 4 to18 migraine attacks of moderate or severe intensity per month within the last 3 months prior to the Screening Visit (month is defined as 4 weeks for the purpose of this protocol).
• 4 or more migraine days during Observation Period.
• Not more than 18 headache days during the Observation Period.
• Ability to distinguish migraine attacks from tension/cluster headaches.
• Subjects on prophylactic migraine medication are permitted to remain on therapy if the dose has been stable for at least 3 months (12 weeks) prior to the Observation Period, and the dose is not expected to change during the course of the study.
• Subjects with contraindications for use of triptans may be included provided they meet all other study entry criteria.