A migraine day was defined as any calendar day in which participant (1) had a qualified migraine headache or (2) took acute migraine-specific medication (i.e., triptan, ergotamine, lasmiditan, or ubrogepant) to treat headache or aura. A qualified migraine headache was defined as a migraine with or without aura, lasting for >=30 minutes, met criteria: >=2 of pain features: unilateral location; pulsating quality (throbbing); moderate or severe pain intensity; aggravation by or causing avoidance of routine physical activity (e.g., walking or climbing stairs) or >=1 of associated symptoms: nausea and/or vomiting; photophobia and phonophobia. Number of migraine days per month were prorated to 28 days.

DBT migraine analysis set: enrolled participants who were randomized only once, took >=1 dose of DB study drug (rimegepant or placebo), and had >=14 days of electronic diary (e-diary) efficacy data (not necessarily consecutive) in both OP and >=1 month (4-week interval) in the DBT Phase.

Moderate or severe MD: a MD of moderate or severe headache pain intensity. MD: any calendar day in which participant (1) had a qualified migraine headache or (2) took acute migraine-specific medication (i.e., triptan, ergotamine, lasmiditan, or ubrogepant) to treat headache or aura. Qualified migraine headache: migraine with or without aura, lasting for >=30 minutes, met criteria: >=2 of pain features: unilateral location; pulsating quality (throbbing); moderate or severe pain intensity; aggravation by or causing avoidance of routine physical activity (e.g., walking or climbing stairs) or >=1 of associated symptoms: nausea and/or vomiting; photophobia and phonophobia. Number of moderate or severe MD per month were prorated to 28 days and derived from data in the on-DBT efficacy analysis period as follows: 28*(total number of moderate or severe MD through Month 3 [Weeks 1 to 12])/(total number of e-diary efficacy data days through Month 3 [Weeks 1 to 12]).

DBT migraine analysis set: enrolled participants who were randomized only once, took >=1 dose of DB study drug (rimegepant or placebo), and had >=14 days of e-diary efficacy data (not necessarily consecutive) in both OP and >=1 month (4-week interval) in the DBT Phase.

A migraine day was defined as any calendar day in which participant (1) had a qualified migraine headache or (2) took acute migraine-specific medication (i.e., triptan, ergotamine, lasmiditan, or ubrogepant) to treat headache or aura. A qualified migraine headache was defined as a migraine with or without aura, lasting for >=30 minutes, met criteria: >=2 of pain features: unilateral location; pulsating quality (throbbing); moderate or severe pain intensity; aggravation by or causing avoidance of routine physical activity (e.g., walking or climbing stairs) or >=1 of associated symptoms: nausea and/or vomiting; photophobia and phonophobia. Number of migraine days per month were prorated to 28 days.

DBT migraine analysis set: enrolled participants who were randomized only once, took >=1 dose of DB study drug (rimegepant or placebo), and had >=14 days of e-diary efficacy data (not necessarily consecutive) in both OP and >=1 month (4-week interval) in the DBT Phase.

A migraine day was defined as any calendar day in which participant (1) had a qualified migraine headache or (2) took acute migraine-specific medication (i.e., triptan, ergotamine, lasmiditan, or ubrogepant) to treat headache or aura. A qualified migraine headache was defined as a migraine with or without aura, lasting for >=30 minutes, met criteria: >=2 of pain features: unilateral location; pulsating quality (throbbing); moderate or severe pain intensity; aggravation by or causing avoidance of routine physical activity (e.g., walking or climbing stairs) or >=1 of associated symptoms: nausea and/or vomiting; photophobia and phonophobia. Number of migraine days per month were prorated to 28 days.

DBT migraine analysis set: enrolled participants who were randomized only once, took >=1 dose of DB study drug (rimegepant or placebo), and had >=14 days of e-diary efficacy data (not necessarily consecutive) in both OP and >=1 month (4-week interval) in the DBT Phase.

MSQ version 2.1 was a self-administered, 14-item instrument validated in 3 domains: role function-restrictive (7 items), role function-preventive (4 items), emotional function (3 items). The restrictive role function domain consisted of 7 items that described how migraine limited one's daily social and work-related activities. Each item was scored on 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.

DBT efficacy analysis set: enrolled participants who were randomized only once and took >=1 dose of DB study drug (rimegepant or placebo). Here, "Overall Number of Participants Analyzed" signifies number of participants in the DBT efficacy analysis set evaluable for this outcome measure.

MIBS was a 4-item self-administered questionnaire that measures: impairment in work or school, impairment in family and social life, difficulty making plans or commitments, and emotional/affective and cognitive distress. Each item was rated on a 6-point scale as: don't know/ not applicable; never; rarely; some of the time; much of the time; most or all of the time. The MIBS score was the weighted sum of the item scores and ranged from 0 to 12. Higher scores indicated a greater impact of headaches on the participant's life between headache attacks.

DBT efficacy analysis set: enrolled participants who were randomized only once and took >=1 dose of DB study drug (rimegepant or placebo). Here, "Overall Number of Participants Analyzed" signifies number of participants in the DBT efficacy analysis set evaluable for this outcome measure.

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. AE intensity included mild, moderate and severe, where Mild: usually transient and required only minimal treatment or therapeutic intervention. Event did not generally interfere with usual activities of daily living. Moderate: usually alleviated with additional specific therapeutic intervention. Event interfered with usual activities of daily living, causing discomfort but poses no significant or permanent risk of harm to participant. Severe: interrupted usual activities of daily living, significantly affected clinical status, or required intensive therapeutic intervention. Participants were counted once in each intensity category based on greatest intensity of unique adverse event preferred terms.

DBT SAS: enrolled participants who took >=1 dose of DB study drug (rimegepant or placebo).

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. AE intensity included mild, moderate and severe, where Mild: usually transient and required only minimal treatment or therapeutic intervention. Event did not generally interfere with usual activities of daily living. Moderate: usually alleviated with additional specific therapeutic intervention. Event interfered with usual activities of daily living, causing discomfort but poses no significant or permanent risk of harm to participant. Severe: interrupted usual activities of daily living, significantly affected clinical status, or required intensive therapeutic intervention. Participants were counted once in each intensity category based on greatest intensity of unique adverse event preferred terms.

Open-label (OL) SAS: enrolled participants who took >= 1 dose of OL rimegepant.

A serious adverse event (SAE) was any event that met any of the following criteria at any dose: resulted in death; was life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent or significant disability/ incapacity; resulted in congenital anomaly/birth defect in the offspring who received rimegepant and other important medical events.

DBT SAS: enrolled participants who took >=1 dose of DB study drug (rimegepant or placebo).

A SAE was any event that met any of the following criteria at any dose: resulted in death; was life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent or significant disability/ incapacity; resulted in congenital anomaly/birth defect in the offspring who received rimegepant and other important medical events.

OL SAS: enrolled participants who took >= 1 dose of OL rimegepant.

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 AEs leading to discontinuation of study drug were reported.

DBT SAS: enrolled participants who took >=1 dose of DB study drug (rimegepant or placebo).

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 AEs leading to discontinuation of study drug were reported.

OL SAS: enrolled participants who took >= 1 dose of OL rimegepant.

Laboratory tests included hematology and serum chemistry. All laboratory tests except glucose were graded according to National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) version (v)5.0, where Grade 3=severe events which require hospitalization or prolongation of hospitalization and Grade 4=life-threatening consequences requiring urgent intervention. Glucose was graded according to Division of Acquired Immune Deficiency Syndrome table for Grading Severity of Adult and Pediatric Adverse Events v2.1. Only those Grade 3 or 4 laboratory tests with non-zero values in any of treatment arms are reported in this outcome measure.

DBT SAS: enrolled participants who took >=1 dose of DB study drug (rimegepant or placebo). Participants mentioned for "Overall Number of Participants Analyzed" may not appear as "Number Analyzed", but they contributed to the data. Here, "Number Analyzed" denotes the number of participants in DBT SAS with non-missing data in the on-DBT safety analysis duration for a given laboratory test.

Laboratory tests included hematology and serum chemistry. All laboratory tests except glucose were graded according to NCI CTCAE v5.0, where Grade 3=severe events which require hospitalization or prolongation of hospitalization and Grade 4=life-threatening consequences requiring urgent intervention. Glucose was graded according to Division of Acquired Immune Deficiency Syndrome table for Grading Severity of Adult and Pediatric Adverse Events v2.1. Only those Grade 3 or 4 laboratory tests with non-zero values in any of treatment arms are reported in this outcome measure.

OL SAS: enrolled participants who took >= 1 dose of OL rimegepant. Participants mentioned for "Overall Number of Participants Analyzed" may not appear as "Number Analyzed", but they contributed to the data. Here, "Number Analyzed" denotes the number of participants in OL SAS with non-missing data in the on-OL rimegepant safety analysis duration for a given laboratory test.

A migraine day was defined as any calendar day in which participant (1) had a qualified migraine headache or (2) took acute migraine-specific medication (i.e., triptan, ergotamine, lasmiditan, or ubrogepant) to treat headache or aura. A qualified migraine headache was defined as a migraine with or without aura, lasting for >=30 minutes, met criteria: >=2 of pain features: unilateral location; pulsating quality (throbbing); moderate or severe pain intensity; aggravation by or causing avoidance of routine physical activity (e.g., walking or climbing stairs) or >=1 of associated symptoms: nausea and/or vomiting; photophobia and phonophobia. Number of migraine days per month were prorated to 28 days and derived from data in the 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]).

DBT migraine analysis set: enrolled participants who were randomized only once; took >=1 dose of DB study drug (rimegepant or placebo) and had >=14 days of e-diary efficacy data (not necessarily consecutive) in both OP and >=1 month (4-week interval) in the DBT Phase.

An acute migraine-specific medication day was defined as any calendar day during which a participant took a migraine-specific acute migraine medication (i.e., triptan, ergotamine, lasmiditan, or ubrogepant) to treat headache or aura. The number of acute migraine-specific medication days per month were prorated to 28 days.

DBT migraine analysis set: enrolled participants who were randomized only once; took >=1 dose of DB study drug (rimegepant or placebo) and had >=14 days of e-diary efficacy data (not necessarily consecutive) in both OP and >=1 month (4-week interval) in the DBT Phase.

MIBS was a 4-item self-administered questionnaire that measures: impairment in work or school, impairment in family and social life, difficulty making plans or commitments, and emotional/affective and cognitive distress. Each item was rated on a 6-point scale as: don't know/ not applicable; never; rarely; some of the time; much of the time; most or all of the time. The MIBS score was the weighted sum of the item scores and ranged from 0 to 12. Higher scores indicated a greater impact of headaches on the participant's life between headache attacks.

DBT efficacy analysis set: enrolled participants who were randomized only once and took >=1 dose of DB study drug (rimegepant or placebo). Participants mentioned for "Overall Number of Participants Analyzed" may not appear as "Number Analyzed", but they contributed to the data. Here, "Number Analyzed" signifies number of participants evaluable for the specified rows.

MSQ was a self-administered, 14-item instrument validated in 3 domains: role function-restrictive (7 items), role function-preventive (4 items), emotional function (3 items). Each item was scored on 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 domain scores are computed as a sum of item responses and rescaled to a 0 to 100 scale such that lower score (0) indicated poor quality of life and higher scores (100) indicated better quality of life.

DBT efficacy analysis set: enrolled participants who were randomized only once and took >=1 dose of DB study drug (rimegepant or placebo). Participants mentioned for "Overall Number of Participants Analyzed" may not appear as "Number Analyzed", but they contributed to the data. Here, "Number Analyzed" signifies number of participants evaluable for the specified rows.

MFIQ was a 26-item participant-report questionnaire. It is designed to measure the subjective impact of migraine on physical, social, and emotional functioning over 5 domains: physical function (5 items), usual activities (10 items), social function (5 items), emotional function (5 items) and overall impact on usual activities (16 items). Participants responded to items using a 5-point scale assigned scores from 1 to 5, with 5 representing the greatest burden. Each domain score was calculated as the sum of the item responses and rescaled to a 0 to 100 scale, with higher scores representing greater burden. The recall period was the past 7 days.

DBT efficacy analysis set: enrolled participants who were randomized only once and took >=1 dose of DB study drug (rimegepant or placebo). Participants mentioned for "Overall Number of Participants Analyzed" may not appear as "Number Analyzed", but they contributed to the data. Here, "Number Analyzed" signifies number of participants evaluable for the specified rows.

The WPAI was a 6-item participant-administered questionnaire used to capture work impairment due to migraine pain. The questions are as follows: Q1 = currently employed (yes/no); Q2 = hours missed due to health problems; Q3 = hours missed due to other reasons; Q4 = hours actually worked; Q5 = degree health affected productivity while working (0-10 scale, with higher numbers indicating less productivity); Q6 = degree health affected regular activities (0-10 scale, with higher numbers indicating greater impairment of regular activities). The absenteeism score was calculated from Q2 and Q4 for participants who responded "yes" to Q1 and ranged from 0 to 100 with higher score indicating greater impairment and less productivity.

DBT efficacy analysis set: enrolled participants who were randomized only once and took >=1 dose of DB study drug (rimegepant or placebo). Participants mentioned for "Overall Number of Participants Analyzed" may not appear as "Number Analyzed", but they contributed to the data. Here, "Number Analyzed" signifies number of participants evaluable for the specified rows.

The WPAI was a 6-item participant-administered questionnaire used to capture work impairment due to migraine pain. The questions are as follows: Q1 = currently employed (yes/no); Q2 = hours missed due to health problems; Q3 = hours missed due to other reasons; Q4 = hours actually worked; Q5 = degree health affected productivity while working (0-10 scale, with higher numbers indicating less productivity); Q6 = degree health affected regular activities (0-10 scale, with higher numbers indicating greater impairment of regular activities). The presenteeism score was calculated using Q5 for participants who responded "yes" to Q1 and had Q4>0 and ranged from 0 to 100 with higher score indicating greater impairment and less productivity.

DBT efficacy analysis set: enrolled participants who were randomized only once and took >=1 dose of DB study drug (rimegepant or placebo). Participants mentioned for "Overall Number of Participants Analyzed" may not appear as "Number Analyzed", but they contributed to the data. Here, "Number Analyzed" signifies number of participants evaluable for the specified rows.

The WPAI was a 6-item participant-administered questionnaire used to capture work impairment due to migraine pain. The questions are as follows: Q1 = currently employed (yes/no); Q2 = hours missed due to health problems; Q3 = hours missed due to other reasons; Q4 = hours actually worked; Q5 = degree health affected productivity while working (0-10 scale, with higher numbers indicating less productivity); Q6 = degree health affected regular activities (0-10 scale, with higher numbers indicating greater impairment of regular activities). The work productivity loss score was calculated using Q2, Q4, and Q5 for participants who responded "yes" to Q1 and ranged from 0 to 100 with higher score indicating greater impairment and less productivity.

DBT efficacy analysis set: enrolled participants who were randomized only once and took >=1 dose of DB study drug (rimegepant or placebo). Participants mentioned for "Overall Number of Participants Analyzed" may not appear as "Number Analyzed", but they contributed to the data. Here, "Number Analyzed" signifies number of participants evaluable for the specified rows.

The WPAI was a 6-item participant-administered questionnaire used to capture work impairment due to migraine pain. The questions are as follows: Q1 = currently employed (yes/no); Q2 = hours missed due to health problems; Q3 = hours missed due to other reasons; Q4 = hours actually worked; Q5 = degree health affected productivity while working (0-10 scale, with higher numbers indicating less productivity); Q6 = degree health affected regular activities (0-10 scale, with higher numbers indicating greater impairment of regular activities). The activity impairment score was calculated using Q6 and ranged from 0 to 100 with higher score indicating greater impairment and less productivity.

DBT efficacy analysis set: enrolled participants who were randomized only once and took >=1 dose of DB study drug (rimegepant or placebo). Participants mentioned for "Overall Number of Participants Analyzed" may not appear as "Number Analyzed", but they contributed to the data. Here, "Number Analyzed" signifies number of participants evaluable for the specified rows.

The PGA scale was a single item assessment that measured the participant's overall assessment of migraine on a 5-point scale as: (1) very good: asymptomatic and no limitation of normal activities; (2) good: mild symptoms and no limitation of normal activities; (3) fair: moderate symptoms and limitation of some normal activities; (4) poor: severe symptoms and inability to carry out most normal activities; (5) very poor: very severe symptoms which are intolerable and inability to carry out all normal activities. Lower scores indicated fewer symptoms and less disability to carry out normal activities.

DBT efficacy analysis set: enrolled participants who were randomized only once and took >=1 dose of DB study drug (rimegepant or placebo). Participants mentioned for "Overall Number of Participants Analyzed" may not appear as "Number Analyzed", but they contributed to the data. Here, "Number Analyzed" signifies number of participants evaluable for the specified rows.