Evaluating the wearing-off effects of fremanezumab in high-frequency episodic migraine and chronic migraine: A real-world observational study in Japan

Objective: To determine the rate of wearing-off effects of monthly and quarterly dosing of fremanezumab based on real-world data. Methods: We conducted an observational, single-center cohort study including 101 high-frequency episodic migraine or chronic migraine patients receiving fremanezumab over a 9-month observation period. Weekly migraine days (WMDs) were assessed by headache diaries. Regarding monthly dosing, comparisons of WMDs were performed between week (W) 1–2 and W3–4 and between W2 and W4 in months 3, 6 and 9. Regarding quarterly dosing, comparisons of WMDs were performed between W1–2 and W11–12 and between W2 and W12 in the first, second and third quarters. Wearing-off effects were defined as a >1 day increase in WMDs at any of the 3 time points. Results: There was no increase in mean WMDs at the end or the second half of the week in the monthly and quarterly dosing groups over 9 months. Wearing-off effects occurred in 6.7–11.7% of the 60 patients in the monthly dosing group and 9.8% of the 41 patients in the quarterly dosing group. Conclusion: Our findings of a low incidence of wearing-off effects support the sustainability of the effect of fremanezumab as headache prophylaxis.