Efficacy and Safety Study of Rimegepant in Episodic Migraine Prevention With Multiple Dosing Regimens

Mean Change From Observation Phase (OP) in the Number of Migraine Days Per Month Over Entire DBT Phase (Weeks 1 to 12)

Time frame · Observation phase (from 31 days prior to randomization), DBT phase (through Month 3 [Week 1 to 12])

A migraine day was defined as any calendar day in which the participant experienced a qualified migraine headache (onset, continuation, or recurrence of the migraine headache). A qualified migraine headache was defined as a migraine with or without aura, lasting for \>=30 minutes, and meeting either \>=2 of the pain features: unilateral location; pulsating quality; moderate or severe pain intensity; aggravation by or causing avoidance of routine physical activity OR \>=1 of the associated symptoms: nausea and/or vomiting; photophobia and phonophobia. The number of migraine days per month were prorated to 28 days and derived for a month in on-DBT efficacy analysis period as follows: 28\*(total number of migraine days through Month 3 \[Weeks 1 to 12\]/ (total number of e-diary efficacy data days through Month 3 \[Weeks 1 to 12\]). Mean change in number of migraine days per month in DBT phase as compared to OP phase was calculated and reported in this outcome measure.

Percentage of Participants With Greater Than Equal to (>=) 50 Percent (%) Reduction From OP in Number of Moderate to Severe Migraine Days Per Month Over the Entire DBT Phase (Weeks 1 to 12)

Time frame · DBT phase (through Month 3 [Week 1 to 12])

Percentage of participants with \>= 50% reduction from OP, in number of migraine days (moderate or severe) in the overall DBT phase is reported in this outcome measure. The number of migraine days per month were prorated to 28 days and derived for a month in on-DBT efficacy analysis period as follows: 28\*(total number of migraine days through Month 3 \[Weeks 1 to 12\]/ (total number of e-diary efficacy data days through Month 3 \[Weeks 1 to 12\]).

Mean Change From OP in the Number of Migraine Days Per Month in the Last 4 Weeks (Weeks 9 to 12) of DBT Phase

Time frame · Observation phase (from 31 days before randomization), Week 9 to Week 12 of the DBT phase

A migraine day was defined as any calendar day in which the participant experienced a qualified migraine headache (onset, continuation, or recurrence of the migraine headache). A qualified migraine headache was defined as a migraine with or without aura, lasting for \>=30 minutes, and meeting either \>=2 of the pain features: unilateral location; pulsating quality; moderate or severe pain intensity; aggravation by or causing avoidance of routine physical activity OR \>=1 of the associated symptoms: nausea and/or vomiting; photophobia and phonophobia. The number of migraine days per month were prorated to 28 days and derived a month (i.e., 4-week interval) in on-DBT efficacy analysis period as follows: 28\*(total number of migraine days in the month) / (total number of e-diary efficacy data in the month). Mean change in number of migraine days per month in the last 4 weeks of DBT phase as compared to OP phase was calculated and reported in this outcome measure.

Mean Change From OP in the Number of Migraine Days Per Month in the First 4 Weeks (Weeks 1 to 4) of DBT Phase

Time frame · Observation phase (from 31 days before randomization), Week 1 to Week 4 of the DBT phase

A migraine day was defined as any calendar day in which the participant experienced a qualified migraine headache (onset, continuation, or recurrence of the migraine headache). A qualified migraine headache was defined as a migraine with or without aura, lasting for \>=30 minutes, and meeting either \>=2 of the pain features: unilateral location; pulsating quality; moderate or severe pain intensity; aggravation by or causing avoidance of routine physical activity OR \>=1 of the associated symptoms: nausea and/or vomiting; photophobia and phonophobia. The number of migraine days per month were prorated to 28 days and derived a month (i.e., 4-week interval) in on-DBT efficacy analysis period as follows: 28\*(total number of migraine days in the month / (total number of e-diary efficacy data in the month. Mean change in number of migraine days per month in the first 4 weeks of DBT phase as compared to OP phase was calculated and reported in this outcome measure.

Mean Number of Acute Migraine-Specific Medication Days Per Month Over the Entire DBT Phase (Weeks 1 to 12)

Time frame · DBT phase (through Month 3 [Week 1 to 12])

An acute migraine-specific medication day was defined as any calendar day during which the participant took a migraine-specific medication (i.e., triptan or ergotamine). The number of acute migraine-specific medication days per month were prorated to 28 days and derived for on-DBT efficacy analysis period as follows: 28\*(total number of acute migraine-specific medication days through Month 3/ (total number of e-Diary efficacy data days through Month 3).

Mean Change From Baseline in the Migraine-Specific Quality-of-Life Questionnaire (MSQoL) Version 2.1 Restrictive Role Function Domain Score at Week 12 of the DBT Phase

Time frame · Baseline (Day 1), Week 12 of the DBT phase

MSQoL is a self-administered, 14-item instrument validated in 3 domains: role restriction, role prevention, and the emotional function. The restrictive role function domain consisted of 7 items that described how migraine limited one's daily social and work-related activities. Participants were required to respond to items using a 6-point scale ranging from 1 to 6, where "1: none of the time," "2: a little bit of the time," "3: some of the time," "4: a good bit of the time," "5: most of the time," and "6: all of the time,". Item scores were recoded using (7 - original score). Raw dimension scores for restrictive role function domain were computed as a sum of recoded item scores and rescaled from a 0 to 100 scale such that lower score (0) indicated poor quality of life and higher scores (100) indicated better quality of life.

Number of Participants With Mild, Moderate and Severe Adverse Events (AEs) in DBT Phase

Time frame · DBT: From Week 1 to Week 20

An AE was defined as any new untoward medical occurrence or worsening of a pre-existing medical condition in a participant or clinical investigation participant administered an investigational (medicinal) product and that did not necessarily have a causal relationship with this treatment. AEs were categorized as mild: usually transient and required only minimal treatment or therapeutic intervention. The event did not generally interfere with usual activities of daily living. Moderate: was usually alleviated with additional specific therapeutic intervention. The event interfered with usual activities of daily living, causing discomfort but posed no significant or permanent risk of harm to the participant. Severe: Interrupted usual activities of daily living, significantly affected clinical status, or required intensive therapeutic intervention. AEs included both non-SAEs and serious adverse events (SAEs).

Number of Participants With Mild, Moderate and Severe AEs OLE Phase

Time frame · OLE: From Week 12 to Week 32

An AE was defined as any new untoward medical occurrence or worsening of a pre-existing medical condition in a participant or clinical investigation participant administered an investigational (medicinal) product and that did not necessarily have a causal relationship with this treatment. AEs were categorized as mild: usually transient and required only minimal treatment or therapeutic intervention. The event did not generally interfere with usual activities of daily living. Moderate: was usually alleviated with additional specific therapeutic intervention. The event interfered with usual activities of daily living, causing discomfort but posed no significant or permanent risk of harm to the participant. Severe: Interrupted usual activities of daily living, significantly affected clinical status, or required intensive therapeutic intervention. AEs included both non-SAEs and SAEs.

Number of Participants With Serious Adverse Events (SAEs) in DBT Phase

Time frame · DBT: From Week 1 to Week 20

An AE was defined as any new untoward medical occurrence or worsening of a pre-existing medical condition in a participant or clinical investigation participant administered an investigational (medicinal) product and that did not necessarily have a causal relationship with this treatment. An SAE was any event that met any of the following criteria at any dose: death; life-threatening; inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity; congenital anomaly/birth defect in the offspring of the participant who received rimegepant and other important medical events.

Number of Participants With SAEs in OLE Phase

Time frame · OLE: From Week 12 to Week 32

An AE was defined as any new untoward medical occurrence or worsening of a pre-existing medical condition in a participant or clinical investigation participant administered an investigational (medicinal) product and that did not necessarily have a causal relationship with this treatment. An SAE was any event that met any of the following criteria at any dose: death; life-threatening; inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity; congenital anomaly/birth defect in the offspring of the participant who received rimegepant and other important medical events.

Number of Participants With AEs Leading to Study Drug Discontinuation in DBT Phase

Time frame · DBT: From Week 1 to Week 12

An AE was defined as any new untoward medical occurrence or worsening of a pre-existing medical condition in a participant or clinical investigation participant administered an investigational (medicinal) product and that did not necessarily have a causal relationship with this treatment. In this outcome measure, participants with adverse events leading to study drug discontinuation were reported.