Background and importance Monoclonal antibodies against calcitonin gene-related peptide or its receptor (mAb-CGRP) offer improvements over available drugs in migraine prophylaxis. Safety and persistence are essential to achieve disease management goals.

Aim and objectives To assess the persistence and safety of mAb-CGRP in patients with chronic migraine in clinical practice.

Material and methods In this observational retrospective single-centre study, all patients with chronic migraine treated for at least 1 month with mAb-CGRP between December 2019 and September 2021 were included.

The primary outcome was first- and second-line persistence (patients treated less than 3 months were excluded), which was analysed using Kaplan–Meier survival curves and the log-rank test for comparison. Secondary outcomes were adverse effect rate and reasons for discontinuation.

Variables collected were age, sex, number of migraines/month, previous treatments, mAb-CGRP type, start and discontinuation date, reasons for discontinuation, mAb-CGRP switching and adverse effects (AEs).

Results Ninety-four patients with median migraines/month of 14 (IQR 10–20) were included; median age: 50 years (IQR 44–58); 84.04% women. All patients received at least three previous preventive treatments: botulinum toxin (100%), tricyclic antidepressants (90.43%), neuromodulators (88.30%), calcium-channel blockers (64.89%), beta-blockers (59.57%) and others (21.28%).

The main reason for discontinuation was ineffectiveness (80.77%). Other reasons were treatment ending, pregnancy, loss of follow-up and patient’s decision.

Median overall persistence for first- and second-line treatment was 13.6 months (95% CI 11.01 to 16.19) and 9.0 months (95% CI 4.61 to 13.39), respectively. Median persistence in first line for erenumab was 13.4 months (95% CI 10.94 to 15.86), for galcanezumab 15.3 months (95% CI 11.81 to 18.79) and fremanezumab was not reached (p>0.05). The 12-month overall persistence rates for first and second line were 67.04% and 52.10%, respectively (p>0.05).

AEs appeared in 21 patients: constipation (8.51%), injection-related headache (5.32%), fatigue/arthralgia (4.26%), injection-site reaction (4.26%), vertigo (2.13%) and menstrual disorders (2.13%). Other AEs were weight loss, insomnia and alopecia. One patient discontinued due to hypersensitivity.

Conclusion and relevance First- and second-line treatment with mAb-CGRP showed similar levels of persistence. First-line erenumab and galcanezumab also demonstrated the same results. The frequency of AEs is lower than reported in clinical trials, so we can conclude that mAb-CGRPs are safe drugs.

Conflict of interest No conflict of interest