Background and Importance Migraine therapy is a major challenge. Monoclonal antibodies against calcitonin gene-related peptide (anti-CGRP mAb), as fremanezumab and erenumab, are indicated for migraine prophylaxis in adults.

Little is known about the comparative persistence of fremanezumab and erenumab, two anti-CGRP mAbs commonly used in our clinical practice.

Aim and Objectives To compare the persistence of fremanezumab and erenumab in patients with migraine and to identify factors associated with it.

Material and Methods We conducted a retrospective, non-interventional, longitudinal study. All chronic or episodic migraine naive patients over 18 years treated with fremanezumab or erenumab in our centre were included.

Persistence was defined as the duration of time from initiation to discontinuation of therapy (last dispensing or end of follow-up in August 2023). Permissible gap (days between two prescription fills exceeding the allowable refill period) was 60 days.

Covariates collected from medical record were: age, gender, baseline migraine days per month (MDM) and Medication Possession Ratio (MPR).

We compared qualitative variables using the χ² distribution. For quantitative variables, we used either the Mann-Whitney U test or the Student’s t-distribution based on normality assessment.

Kaplan-Meier survival analysis was performed and differences were evaluated using the log-rank test. Adjusted risk of discontinuation was assessed with Cox Proportional Hazard models. Significance level was 0.05.

Results Eighty patients were included, 86.3% were female. Age (mean±SD) was 48±10 years. MPR was 98.4±4.1, 61.3% were treated with fremanezumab. Baseline MDM (median) was 17 days (IQ 12–28). There were no statistically significant differences between the groups.

Overall, mean persistence duration was 482 days (CI 95% 404–559). Persistence with fremanezumab was 743 days (CI 95% 638–848) and persistence with erenumab was 548 days (CI 95% 368–729);p=0.001. According to adjusted Cox-model by MDM HR was 3.5 (CI 95% 1.7–6.9;p=0.001) for anti-CGRP mAb and 1.1 (CI 95%, 1.04–1.15 p=0.001) for baseline MDM.

Conclusion and Relevance In our study, naive patients treated with fremanezumab had higher persistence rates than those treated with erenumab. Baseline MDM was also found to influence persistence.

Conflict of Interest No conflict of interest.