Total Migraine Freedom, a Potential Primary Endpoint to Assess Acute Treatment in Migraine: Comparison to the Current FDA Requirement Using the Complete Rizatriptan Study Database

Objective.- To examine total migraine freedom (TMF), defined as pain freedom and absence of associated symptoms, using rizatriptan clinical trial data and to explore advantages of TMF as a single primary composite efficacy endpoint. Background.- The FDA has set a higher regulatory hurdle for registration of new migraine agents requiring both pain freedom (or relief) and absence of each associated symptom (phonophobia, photophobia, and nausea). Methods.- Twelve studies representing phase III + efficacy/safety studies of rizatriptan 10 mg in adults treating migraine were included in the meta-analysis. The percentage of patients achieving TMF at 2 hours by study and combined by treatment group was summarized by treatment paradigm (early/mild pain, moderate/severe, menstrual migraine). To demonstrate the impact of the strict migraine regulatory hurdle on clinical trial design and to compare it to TMF, simulation via bootstrap sampling was used. Results.- Odds ratios (rizatriptan vs placebo, all P < .001) for TMF were 6.2 (95% CI: [4.9, 7.7]) for moderate/severe, 2.7 (95% CI: [1.8, 4.0]) for menstrual, and 3.1 (95% CI: [2.4, 4.0]) for early/mild. Most with moderate/severe migraine reported photophobia and/or phonophobia at baseline, but only half had nausea. Simulation results showed a substantial loss of power analyzing absence of pain and each symptom compared with the composite TMF endpoint across all treatment paradigms. Conclusion.- Rizatriptan 10 mg was superior to placebo in achieving TMF at 2 hours post-dose across all treatment paradigms. Given that the majority of patients with migraine do not exhibit all 3 associated symptoms, the TMF endpoint has significant advantages vs establishing efficacy on pain and each symptom individually.