A Study to Learn About the Study Medicine Called Rimegepant in Adults When Used for the Prevention of Chronic Migraine

AN INTERVENTIONAL EFFICACY AND SAFETY, PHASE 3, DOUBLE-BLIND, RANDOMIZED, 2-ARM STUDY TO INVESTIGATE THE PREVENTION OF CHRONIC MIGRAINE WITH RIMEGEPANT COMPARED WITH PLACEBO IN PARTICIPANTS 18 YEARS OF AGE OR OLDER

Rimegepant is a calcitonin gene-related peptide (CGRP) receptor antagonist approved for the acute treatment of migraine attacks in adults and for the preventive treatment of episodic migraine in adults when administered every other day. This study evaluates once daily rimegepant for the preventive treatment of chronic migraine.

After a 28-day observation period without study intervention, eligible participants will be randomized in a 1:1 ratio to receive either rimegepant 75 mg orally disintegrating tablet (ODT) or matching placebo once daily for 12 weeks under double-blind conditions. Participants who remain eligible at the end of the double-blind treatment phase will enter a 12-week open-label treatment period, during which all participants will receive open-label rimegepant 75 mg once daily. During this period, participants may also take an additional rimegepant tablet for the acute treatment of breakthrough migraine attacks, up to 10 doses per month. A 28-day follow-up period completes the approximately 32-week study.

The primary objective of the study is to determine whether once-daily rimegepant is more effective than placebo in reducing monthly migraine days relative to the observation period in adults with chronic migraine. Secondary objectives include evaluating differences between rimegepant and placebo in migraine responder rates, headache severity, acute migraine medication use, quality of life, work productivity, cognitive functioning, and safety and tolerability.

Approximately 400 adults aged 18 years or older with a diagnosis of chronic migraine for at least 1 year will be enrolled at multiple study sites.

Study Overview

• Status: Not yet recruiting
• Conditions: Preventive Treatment of Migraine
• Intervention / Treatment: Drug: Rimegepant; Drug: Placebo

Detailed Description

This Phase 3, multicenter, randomized, double-blind, placebo-controlled study will evaluate the efficacy, safety, and tolerability of rimegepant 75 mg administered once daily for the preventive treatment of chronic migraine in adults. Approximately 400 participants with chronic migraine will complete a 28-day Observation Phase and then be randomized in a 1:1 ratio to receive either rimegepant 75 mg or placebo during a 12-week Double-Blind Treatment (DBT) Phase.

The primary objective is to determine whether once-daily rimegepant is superior to placebo in reducing monthly migraine days in adults with chronic migraine. Secondary objectives include evaluation of migraine responder rates, headache frequency and severity, acute migraine medication use, quality of life, headache-related disability, work productivity, cognitive functioning, and patient-reported improvement.

Participants will record migraine and headache information using an electronic diary and will complete protocol-specified efficacy and safety assessments throughout the study. Safety evaluations will include monitoring of adverse events, clinical laboratory assessments, vital signs, electrocardiograms, and other protocol-defined safety measures.

Eligible participants who complete the DBT Phase and remain eligible may enter a 12-week Open-Label Extension (OLE) Phase, during which all participants will receive open-label rimegepant 75 mg once daily. During the OLE Phase, participants may also take an additional dose of rimegepant 75 mg for the acute treatment of breakthrough migraine attacks, up to 10 doses per month. Following completion or discontinuation of study treatment, participants will enter a 28-day Follow-Up Phase.

The study is designed to determine whether once-daily rimegepant provides superior efficacy to placebo for the preventive treatment of chronic migraine in adults and to further characterize the safety and tolerability profile of daily rimegepant administration.

• Study Type: Interventional
• Enrollment (Estimated): 400
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Pfizer CT.gov Call Center; Phone Number: 1-800-718-1021; Email: ClinicalTrials.gov_Inquiries@pfizer.com

Study Locations

• United States
  • California
    • Canoga Park, California, United States, 91303
      • Hope Clinical Research
  • Florida
    • Boca Raton, Florida, United States, 33428
      • Neurology Offices of South Florida PLLC

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Male or female participants ≥18 years of age.
• Diagnosis of chronic migraine, with or without aura, according to International Classification of Headache Disorders, 3rd edition (ICHD-3) criteria.
• History of migraine for at least 1 year before screening.
• Migraine onset before 50 years of age and chronic migraine onset before 65 years of age.
• Migraine attacks lasting 4 to 72 hours when untreated or unsuccessfully treated.
• During the 3 months prior to screening, an average of:
• ≥15 monthly headache days (MHDs),
• including ≥8 monthly migraine days (MMDs),
• and ≥1 non-headache day per month.
• Completion of the Observation Phase and fulfillment of all protocol-defined eligibility requirements prior to randomization.
• Willing and able to comply with study procedures, including completion of the electronic diary.

Exclusion Criteria:

• Prior use of rimegepant for migraine prevention.

• History of treatment failure of:

  • 2 gepants, or
  • 2 CGRP-targeting biologics, or
  • 1 gepant and ≥1 CGRP-targeting biologic.
• Failure of >4 migraine preventive medications, including at least 2 with different mechanisms of action.
• Any medical or psychiatric condition, or clinically significant laboratory abnormality, that in the investigator's judgment may increase risk to the participant or interfere with study participation or interpretation of results. This includes, but is not limited to, uncontrolled hypertension or a history of Raynaud's phenomenon.
• Pregnant, breastfeeding, planning to become pregnant, or planning to initiate breastfeeding during the study.
• Positive amphetamine screening result unless attributable to prescribed stimulant therapy that has been stable for at least 3 months prior to Visit 1 and is expected to remain stable throughout study participation.
• Use of investigational products or participation in another clinical study within protocol-defined exclusion windows.
• Any other condition that, in the opinion of the investigator or sponsor, would make study participation unsafe or compromise study conduct.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Rimegepant 75 mg orally disintegrating tablet (ODT) once daily; Participants will receive rimegepant 75 mg orally disintegrating tablet (ODT) once daily during the 12-week double-blind treatment phase. Eligible participants may subsequently enter a 12-week open-label extension phase and receive open-label rimegepant 75 mg once daily. During the open-label extension phase, participants may also take an additional dose of rimegepant 75 mg for the acute treatment of breakthrough migraine attacks, up to 10 doses per month.	Drug: Rimegepant; Rimegepant 75 mg orally disintegrating tablet (ODT) administered once daily during the 12-week double-blind treatment phase. Participants who enter the 12-week open-label extension phase will receive open-label rimegepant 75 mg once daily. During the open-label extension phase, participants may also take an additional dose of rimegepant 75 mg for the acute treatment of breakthrough headache attacks, up to 10 doses per month.
Placebo Comparator: Matching placebo once daily for 12 weeks during the double-blind treatment phase; Participants will receive matching placebo once daily during the 12-week double-blind treatment phase. Eligible participants may subsequently enter a 12-week open-label extension phase and receive open-label rimegepant 75 mg once daily. During the open-label extension phase, participants may also take an additional dose of rimegepant 75 mg for the acute treatment of breakthrough migraine attacks, up to 10 doses per month.	Drug: Placebo; Matching placebo orally disintegrating tablet administered once daily during the 12-week double-blind treatment phase. Participants who enter the 12-week open-label extension phase will receive open-label rimegepant 75 mg once daily. During the open-label extension phase, participants may also take an additional dose of rimegepant 75 mg for the acute treatment of breakthrough headache attacks, up to 10 doses per month.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change From Observation Phase in Monthly Migraine Days (MMDs) Over the Entire Double-Blind Treatment Phase	Change from the Observation Phase in the number of monthly migraine days (MMDs) over the 12-week Double-Blind Treatment Phase. Monthly migraine days will be assessed using participant-reported electronic diary data.	12 Weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants Achieving a ≥50% Reduction From the Observation Phase in Monthly Migraine Days (MMDs) Over the Entire Double-Blind Treatment Phase	A responder is defined as a participant who achieves a reduction of at least 50% from the Observation Phase in monthly migraine days (MMDs). Monthly migraine days will be determined using participant-reported electronic diary data.	12 Weeks
Change From Observation Phase in Moderate or Severe Monthly Headache Days Over the Entire Double-Blind Treatment Phase	Change from the Observation Phase in the number of moderate or severe monthly headache days. Headache intensity will be recorded using participant-reported electronic diary data.	12 Weeks
Change From Observation Phase in Monthly Acute Migraine Medication Use Days Over the Entire Double-Blind Treatment Phase	Change from the Observation Phase in the number of monthly acute migraine medication use days. Acute migraine medication use will be captured using participant-reported electronic diary data.	12 Weeks
Change From Baseline in Migraine-Specific Quality of Life Questionnaire (MSQ) Restrictive Role Function Domain Score	The Migraine-Specific Quality of Life Questionnaire (MSQ) version 2.1 Restrictive Role Function domain assesses limitations in daily social and work-related activities due to migraine. Scores range from 0 to 100, with higher scores indicating better functioning and fewer migraine-related limitations.	Week 12
Change From Observation Phase in Monthly Migraine Days Over the Entire Double-Blind Treatment Phase in Participants With Historical Medication Overuse Headache and Medication Overuse	Change from the Observation Phase in the number of monthly migraine days among participants with both historical medication overuse headache and medication overuse during the Observation Phase. Monthly migraine days will be determined using participant-reported electronic diary data.	12 Weeks
Change From Baseline in MSQ Restrictive Role Function Domain Score in Participants With Historical Medication Overuse Headache and Medication Overuse	The Migraine-Specific Quality of Life Questionnaire (MSQ) version 2.1 Restrictive Role Function domain assesses limitations in daily social and work-related activities due to migraine. Scores range from 0 to 100, with higher scores indicating better functioning and fewer migraine-related limitations. This analysis will be performed among participants with both historical medication overuse headache and medication overuse during the Observation Phase.	Week 12
Percentage of Participants Achieving Medication Overuse Headache Remission	Percentage of participants with both historical medication overuse headache and medication overuse during the Observation Phase who achieve medication overuse headache remission during the Double-Blind Treatment Phase.	12 Weeks

Collaborators and Investigators

• Sponsor: Pfizer
• Investigators: Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

Helpful Links

• To obtain contact information for a study center near you, click here.

Study record dates

Study Major Dates

• Study Start (Estimated): July 29, 2026
• Primary Completion (Estimated): September 12, 2028
• Study Completion (Estimated): December 11, 2028

Study Registration Dates

• First Submitted: July 22, 2026
• First Submitted That Met QC Criteria: July 22, 2026
• First Posted (Actual): July 27, 2026

Study Record Updates

• Last Update Posted (Actual): July 27, 2026
• Last Update Submitted That Met QC Criteria: July 22, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Migraine Prevention
• Additional Relevant MeSH Terms: rimegepant sulfate
• Other Study ID Numbers: C4951085; 2026-525295-25-00 (Registry Identifier: CTIS (EU))

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No