Efficacy and continuability of 675 mg fremanezumab administration over 2 years.

Background: Real-world data on the long-term adherence to- and efficacy of fremanezumab 675 mg quarterly dosing remain scarce. Our study evaluated the efficacy of- and patient adherence to 675 mg fremanezumab for episodic migraine (EM) and chronic migraine (CM) over 2 years and analyzed the reasons for discontinuation.

Methods: Among patients attending our headache outpatient clinic, those aged ≥ 15 years who commenced fremanezumab 675 mg quarterly dose schedule from November 2021 to June 2022 were enrolled in this single-center observational study. The frequency and severity of headaches were recorded using a headache diary. The observation period ended for each patient at 24 months after treatment initiation. The reasons for discontinuation were documented based on follow-up medical records.

Results: Twenty-eight patients were enrolled, of whom 15 had CM and 13 had EM. One patient with CM was excluded due to withdrawal after the first injection. Of the 27 remaining patients, the treatment was effective in 70.4% (n = 19). 44.4% (n = 12) continued fremanezumab 675 mg until study termination. Among those patients who remained on fremanezumab for two years, seven updated the monthly headache calendars consistently: 2 had CM, and 5 had EM. Mean changes in MMD from the baseline were - 2.2 at 3 months,, -1.8 at 12 months, and - 1.6 (SD = 3.0) at 2 years. Treatment was discontinued because of sustained improvement in 25.9% (n = 7). 22.2% of cases (n = 6) experienced insufficient effectiveness, resulting in discontinuation. One patient (3.7%) discontinued because of injection-site erythema. One patient (3.7%) was discontinued because of pregnancy. Among the non-responders, three switched from fremanezumab to erenumab, with one returning to fremanezumab at a monthly injection of 225 mg after efficacy with erenumab waned. Two patients switched to galcanezumab. All patients who switched medication continued the new medication owing to its effectiveness. One patient was lost to follow-up.

Conclusions: Fremanezumab 675 mg quarterly dose effectively reduces headache frequency over an extended period and may facilitate medication cessation in patients who experience substantial recovery.