Pharmacotherapeutic group: Analgesics, calcitonin gene-related peptide (CGRP) antagonists, ATC code: N02CD06
Mechanism of action
Rimegepant selectively binds with high affinity to the human calcitonin gene-related peptide (CGRP) receptor and antagonizes CGRP receptor function.
The relationship between pharmacodynamic activity and the mechanism(s) by which rimegepant exerts its clinical effects is unknown.
Clinical efficacy: acute treatment
The efficacy of VYDURA for the acute treatment of migraine with and without aura in adults was studied in three randomized, double-blind, placebo-controlled trials (Studies 1-3). Patients were instructed to treat a migraine of moderate to severe headache pain intensity. Rescue medicinal products (i.e., NSAIDs, paracetamol, and/or an antiemetic) was allowed 2 hours after the initial treatment. Other forms of rescue medicinal products such as triptans were not allowed within 48 hours of initial treatment. Approximately 14% of patients were taking preventive medicinal products for migraine at baseline. None of the patients in Study 1 were on concomitant preventive medicinal products that act on the calcitonin gene-related peptide pathway.
The primary efficacy analyses were conducted in patients who treated a migraine with moderate to severe pain. Pain freedom was defined as a reduction of moderate or severe headache pain to no headache pain, and most bothersome symptom (MBS) freedom was defined as the absence of the self-identified MBS (i.e., photophobia, phonophobia, or nausea). Among patients who selected an MBS, the most commonly selected symptom was photophobia (54%), followed by nausea (28%), and phonophobia (15%).
In Study 1, the percentage of patients achieving headache pain freedom and MBS freedom at 2 hours after a single dose was statistically significantly greater in patients who received VYDURA compared to those who received placebo (Table 2). In addition, statistically significant effects of VYDURA compared to placebo were demonstrated for the additional efficacy endpoints of pain relief at 2 hours, sustained pain freedom from 2 to 48 hours, use of rescue medication within 24 hours, and ability to function normally at 2 hours after dosing. Pain relief was defined as a reduction in migraine pain from moderate or severe severity to mild or none. Pivotal single attack, double-blind, placebo-controlled studies 2 & 3 were conducted in patients with migraine who received one 75 mg rimegepant bioequivalent dosage form.
Table 2: Migraine Efficacy Endpoints for Acute Treatment Studies
| | Study 1 | Study 2 | Study 3 |
| VYDURA 75 mg | Placebo | Rimegepant 75 mg | Placebo | Rimegepant 75 mg | Placebo |
| Pain Free at 2 hours | | | | | | |
| n/N* | 142/669 | 74/682 | 105/537 | 64/535 | 104/543 | 77/541 |
| % Responders | 21.2 | 10.9 | 19.6 | 12.0 | 19.2 | 14.2 |
| Difference compared to placebo (%) | 10.3 | | 7.6 | | 4.9 | |
| p-value | | <0.0001 a | | 0.0006a | | 0.0298 a |
| MBS Free at 2 hours | | | | | | |
| n/N* | 235/669 | 183/682 | 202/537 | 135/535 | 199/543 | 150/541 |
| % Responders | 35.1 | 26.8 | 37.6 | 25.2 | 36.6 | 27.7 |
| Difference compared to placebo (%) | 8.3 | | 12.4 | | 8.9 | |
| p-value | | 0.0009 a | | <0.0001 a | | 0.0016 a |
| Pain Relief at 2 hours | | | | | | |
| n/N* | 397/669 | 295/682 | 312/537 | 229/535 | 304/543 | 247/541 |
| % Responders | 59.3 | 43.3 | 58.1 | 42.8 | 56.0 | 45.7 |
| Difference compared to placebo | 16.1 | | 15.3 | | 10.3 | |
| p-value | | <0.0001a | | <0.0001a | | 0.0006a |
| Sustained Pain Freedom 2 to 48 hours | | | | | | |
| n/N* | 90/669 | 37/682 | 53/537 | 32/535 | 63/543 | 39/541 |
| % Responders | 13.5 | 5.4 | 9.9 | 6.0 | 11.6 | 7.2 |
| Difference compared to placebo (%) | 8.0 | | 3.9 | | 4.4 | |
| p-value | | <0.0001a | | 0.0181b | | 0.0130b |
*n=number of responders/N=number of patients in that treatment group
a Significant p-value in hierarchical testing
b Nominal p-value in hierarchical testing
MBS: most bothersome symptom
Figure 1 presents the percentage of patients achieving migraine pain freedom within 2 hours following treatment in Study 1.
Figure 1: Percentage of Patients Achieving Pain Freedom within 2 Hours in Study 1
Figure 2 presents the percentage of patients achieving MBS freedom within 2 hours in Study 1.
Figure 2: Percentage of Patients Achieving MBS Freedom within 2 Hours in Study 1
The incidence of photophobia and phonophobia was reduced at 2 hours following administration of VYDURA 75 mg as compared to placebo in all 3 studies.
Clinical efficacy: prophylaxis
The efficacy of rimegepant was evaluated as a prophylactic treatment of migraine in a randomized, double-blind, placebo-controlled study (Study 4).
Study 4 included male and female adults with at least a 1-year history of migraine (with or without aura). Patients had a history of 4 to 18 migraine attacks of moderate to severe pain intensity per 4-week period within the 12 weeks prior to the screening visit. Patients experienced an average of 10.9 headache days during the 28-day observational period, which included an average of 10.2 migraine days, prior to randomization into the study. The study randomized patients to receive rimegepant 75 mg (N=373) or placebo (N=374) for up to 12 weeks. Patients were instructed to take randomized treatment once every other day (EOD) for the 12-week treatment period. Patients were allowed to use other acute treatments for migraine (e.g., triptans, NSAIDs, paracetamol, antiemetics) as needed. Approximately 22% of patients were taking preventive medicinal products for migraine at baseline. Patients were allowed to continue in an open-label extension study for an additional 12 months.
The primary efficacy endpoint for Study 4 was the change from baseline in the mean number of monthly migraine days (MMDs) during Weeks 9 through 12 of the double-blind treatment phase. Secondary endpoints included the achievement of a ≥ 50% reduction from baseline in monthly moderate or severe migraine days.
Rimegepant 75 mg dosed EOD demonstrated statistically significant improvements for key efficacy endpoints compared to placebo, as summarized in Table 3 and shown graphically in Figure 3.
Table 3: Key Efficacy Endpoints for Study 4
| | Rimegepant 75 mg EOD | Placebo EOD |
| Monthly Migraine Days (MMD) Weeks 9 through 12 | N=348 | N=347 |
| Change from baseline | -4.3 | -3.5 |
| Change compared to placebo | -0.8 | |
| p-value | 0.010a | |
| ≥ 50% Reduction in Moderate or Severe MMDs Weeks 9 through 12 | N=348 | N=347 |
| % Responders | 49.1 | 41.5 |
| Difference compared to placebo | 7.6 | |
| p-value | 0.044a | |
| a Significant p-value in hierarchical testing |
Figure 3: Change from Baseline in Monthly Migraine Days in Study 4
Long-term efficacy
Patients participating in Study 4 were allowed to continue in an open-label extension study for an additional 12 months. Efficacy was sustained for up to 1 year in an open-label study extension in which patients received rimegepant 75 mg every other day plus as needed on non-scheduled dosing days (Figure 4). A portion composed of 203 patients assigned to rimegepant completed the overall 16-month treatment period. In these patients, the overall mean reduction from baseline in the number of MMDs averaged over the 16-month treatment period was 6.2 days.
Figure 4: Longitudinal Plot of the Change in Mean Number of Monthly Migraine Days (MMDs) from the Observation Period Over Time during Double-Blind Treatment (Months 1 to 3) and during Treatment with Open-label Rimegepant (Months 4 to 16)
Paediatric population
The European Medicines Agency has waived the obligation to submit the results of studies with VYDURA in all subsets of the paediatric population in the prophylactic treatment of migraine headaches (see section 4.2 for information on paediatric use).
The European Medicines Agency has deferred the obligation to submit the results of studies with VYDURA in one or more subsets of the paediatric population in the acute treatment of migraine (see section 4.2 for information on paediatric use).