Trial results for a Phase 4 study evaluating rimegepant for the prevention of migraine in adults were posted on ClinicalTrials.gov on 2026-05-22. The study demonstrated that rimegepant reduced the mean number of migraine days per month by 2.1 days over 12 weeks, compared to a 0.5-day reduction with placebo.
Background
The study investigated rimegepant for migraine prophylaxis in adults who had a history of inadequate response to oral preventive medications. This population represents individuals who have not achieved satisfactory migraine prevention with existing oral therapies.
Trial design
The Phase 4 study (NCT05518123) enrolled 962 participants with migraine. The study evaluated the efficacy and tolerability of rimegepant for migraine prophylaxis in adults with a history of inadequate response to oral preventive medications, comparing it against placebo over a 12-week double-blind treatment phase.
Key results
Key efficacy results from the 12-week double-blind treatment phase include:
- Mean Change in Migraine Days Per Month (Weeks 1-12): Rimegepant showed a reduction of -2.1 Migraine Days per month compared to -0.5 Migraine Days per month for placebo. The least square mean difference was -1.6 (95% CI: -2.13, -1.15), p=0.0001.
- Percentage of Participants with >= 50% Reduction in Moderate or Severe Migraine Days (Weeks 1-12): 34.0% of participants in the rimegepant arm achieved this reduction, versus 13.8% in the placebo arm. The difference in percentage was 20.1% (95% CI: 13.7, 26.5), p=0.0001.
- Mean Change in Migraine-Specific Quality-of-Life Questionnaire (MSQ) Restrictive Role Function Domain Score at Week 12: Rimegepant showed a change of 21.1 Units on a scale compared to 14.6 Units on a scale for placebo. The least square mean difference was 6.6 (95% CI: 3.6, 9.54), p=0.0001.
- Mean Change in Migraine Interictal Burden Scale (MIBS) Score at Week 12: Rimegepant showed a change of -1.9 Units on a scale compared to -1.0 Units on a scale for placebo. The least square mean difference was -0.9 (95% CI: -1.36, -0.38), p=0.0006.
Further analysis showed a mean change from observation phase in migraine days per month in the first 4 weeks of the DBT phase of -1.8 for rimegepant versus -0.1 for placebo (LSM difference -1.7, p=0.0001), and in the last 4 weeks of the DBT phase of -2.3 for rimegepant versus -0.9 for placebo (LSM difference -1.4, p=0.0001).
What this means
The results of this Phase 4 study indicate that rimegepant significantly reduced the number of monthly migraine days and improved quality of life measures compared to placebo in adults with a history of inadequate response to oral preventive medications. The observed reduction of -1.6 in least square mean migraine days per month and the 20.1% greater proportion of participants achieving a 50% reduction in moderate or severe migraine days suggest a meaningful clinical benefit for this patient population. These findings support the use of rimegepant as an effective preventive treatment option for individuals who have not responded sufficiently to other oral preventive therapies.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for the study NCT05518123, titled "Efficacy and Tolerability of Rimegepant for the Prevention of Migraine in Adults With History of Inadequate Response to Oral Preventive Medications", were posted on 2026-05-22 on clinicaltrials.gov.