Background and Importance Chronic migraine (CM) is a highly disabling disorder characterised by recurrent episodes of moderate to severe headache. Several preventive treatments are available, including monoclonal antibodies against calcitonin gene-related peptide (CGRP), such as fremanezumab.

Aim and Objectives The aim of this study was to evaluate the persistence, effectiveness and safety of fremanezumab in clinical practice in patients with CM.

Material and Methods This is a restrospective and descriptive study conducted at a tertiary teaching hospital. All patients who started fremanezumab as a first-line anti-CGRP therapy between August 2020 and December 2022 were included. Inclusion criteria were: age ≥ 18 years, diagnosis of CM and a minimum follow-up of 3 months.

Patients demographic and clinical data were obtained from electronic medical records. These data included age, sex, comorbidities, number and type of previous preventive treatments, and monthly migraine days (MMD) at initiation, 3 months and 6 months. Persistence was calculated as the number of days between treatment initiation and discontinuation or the end of study follow-up, whichever occurred first. Efectiveness was calculated considering a ≥50% reduction of mean MMD at 3 and 6 months. Safety was analysed according to the number and type of adverse events that occurred during treatment.

Results A total of 207 patients were included, of whom 190 (92%) were women with a median age of 48 years (18–81 years). The two most frequent comorbidities were depression (23%) and anxiety (20%). Patients had received a mean of 4.6 preventive treatments before anti-CGRP initiation, highlighting the use of antidepressants (72.4%) and onabotulinum toxin (89.3%). At 3 and 6 months of follow-up, persistence were 92.6% and 80.0%, respectively. The percentage of patients who achieved a 50% MMD reduction was 56.8% at 3 months and 54.5% at 6 months. A total of 27 patients (13%) developed side effects during fremanezumab therapy, being the most common allergic reaction or pruritus (11 patients; 5.3%) constipation (5 patients; 2.4%) and injection site reaction (5 patients; 2.4%).

Conclusion and Relevance Our results show that fremanezumab is an effective and safe treatment for CM, which has demonstrated good persistence data in clinical practice.

Conflict of Interest No conflict of interest.