Galcanezumab Efficacy Through the Dosing Interval in Japanese Patients with Episodic Migraine: Post Hoc Analysis of a Phase 2 Randomized Trial

Introduction The efficacy and safety of galcanezumab as a preventive treatment in Japanese patients with episodic migraine was demonstrated in a phase 2, randomized, placebo-controlled trial (conducted December 2016-January 2019). This post hoc analysis assessed the consistency of galcanezumab efficacy through the monthly dosing interval.Methods Patients with 4-14 migraine headache days/month were randomized (2:1:1, stratified by baseline migraine frequency) to subcutaneous placebo (n = 230), 120-mg galcanezumab (with 240-mg loading dose; n = 115) or 240-mg galcanezumab (n = 114) once monthly for 6 months. Outcomes included change from baseline in weekly migraine headache days, proportion of patients with migraine headache on each day, and proportion of patients with worsening migraine headache days during each month ([average of weeks 3-4] - [average of weeks 1-2] > 0).Results In the 120-mg (approved dose) galcanezumab group, mean change from baseline in weekly migraine headache days was consistent and significantly greater (p < 0.05) than placebo for weeks 1-4; efficacy was consistent when averaged across months 1-6 and in most individual months. Averaged across months 1-6, the proportion of patients with migraine headache was significantly lower with galcanezumab than placebo on every day in both dose groups and was not significantly different between days 2 and 28 with 120-mg galcanezumab (p = 0.161). Within each month, the proportion of patients with migraine headache was generally consistent from days 2-28. The proportion of patients with worsening during the dosing interval did not significantly exceed 50% in any group during any month.Conclusions This post hoc analysis supports the consistency of efficacy of galcanezumab across 6 months of treatment and suggests that wearing-off within the dosing interval does not occur on a population level in Japanese patients with episodic migraine.