Trial results for rimegepant for migraine prevention in Japanese subjects were posted on ClinicalTrials.gov on 2025-07-14. The study demonstrated that rimegepant led to a mean reduction of -2.4 migraine days per month from Week 9 to 12, compared to -1.4 days for placebo. This represented a statistically significant difference of -1.1 days (p=0.0021) between the treatment groups.
Background
Rimegepant is being evaluated for the prevention of migraine. This particular study focused on its efficacy and safety in a Japanese population.
Trial design
The study (NCT05399485) was a Phase 3, double-blind, placebo-controlled trial evaluating rimegepant for migraine prevention in Japanese subjects. It enrolled 496 participants with migraine. Participants were randomized to receive either rimegepant or placebo. The trial aimed to assess the efficacy, safety, and tolerability of rimegepant.
Key results
The trial reported several key measurements and analyses regarding migraine prevention:
- Mean Change From Baseline in Number of Migraine Days Per Month From Week 9 to 12 of the Double-Blind Treatment (DBT) Phase:
- Rimegepant group: -2.4 Days/month (Least Squares Mean)
- Placebo group: -1.4 Days/month (Least Squares Mean)
- Percentage of Participants With at Least 50% Reduction From Baseline in the Mean Number of Moderate to Severe Migraine Days Per Month in the Last 4 Weeks (Weeks 9 to 12) of the DBT Phase:
- Rimegepant group: 41.7% of participants
- Placebo group: 34.4% of participants
- Mean Change From Baseline in Number of Migraine Days Per Month Over the Entire DBT Phase (Weeks 1 to 12):
- Rimegepant group: -2.5 Days/month (Least Squares Mean)
- Placebo group: -1.1 Days/month (Least Squares Mean)
- Mean Change From Baseline in Number of Migraine Days Per Month From Week 1 to 4 of the DBT Phase:
- Rimegepant group: -2.7 Days/month (Least Squares Mean)
- Placebo group: -0.8 Days/month (Least Squares Mean)
- Mean Number of Acute Migraine-specific Medication Days Per Month From Week 9 to 12 of the DBT Phase:
- Rimegepant group: 5.0 Days/month (Least Squares Mean)
- Placebo group: 5.8 Days/month (Least Squares Mean)
- Mean Change From Baseline in the Migraine-Specific Quality-of-Life Questionnaire (MSQoL) v 2.1 Role Function - Restrictive Domain Score at Week 12 of the DBT Phase:
- Rimegepant group: 7.8 Score on a scale (Least Squares Mean)
- Placebo group: 3.7 Score on a scale (Least Squares Mean)
Key analyses included:
- For the outcome of mean change from baseline in number of migraine days per month from Week 9 to 12, a Mixed Models Analysis showed a difference in Least Squares Mean of -1.1 (95.0% CI: -1.73 to -0.38) between groups, with a p-value of 0.0021.
- For the percentage of participants with at least 50% reduction in moderate to severe migraine days, a Mantel Haenszel analysis showed a difference in percentage of 7.3 (95.0% CI: -1.4 to 15.9) between groups, with a p-value of 0.0989.
What this means
The results indicate that rimegepant significantly reduced the number of migraine days per month in Japanese subjects compared to placebo, particularly during Weeks 9 to 12 of the treatment phase. The observed reduction in migraine days and the improvement in migraine-specific quality of life scores suggest a clinically meaningful benefit for migraine prevention in this population. While a higher percentage of rimegepant-treated participants achieved at least a 50% reduction in moderate to severe migraine days, this specific outcome did not reach statistical significance (p=0.0989).
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT05399485, titled "Efficacy and Safety Study of Rimegepant for Migraine Prevention in Japanese Subjects (Japan Only)," were posted on 2025-07-14 on clinicaltrials.gov.