Background and importance Migraine is a neurological disorder with a high prevalence. Monoclonal antibodies against the calcitonin gene-related peptide pathway (CGRP-mAbs) are indicated for the prevention of chronic migraine (CM).

Aim and objectives The aim of this study was to assess effectiveness and safety of CGRP-mAbs in CM in clinical practice.

Material and methods Descriptive retrospective study was conducted in patients with CM receiving CGRP-mAbs between May 2018 and September 2021. Electronic clinical history and prescription software Farmatools were used to record data: gender, age, previous preventive treatment, CGRP-mAb prescribed, dosage, duration of therapy and monthly migraine days. Effectiveness was measured by the reduction in pain intensity (any subjective clinical improvement) and the reduction ≥50% of monthly migraine days from baseline. Failure to meet both criteria was considered as non-response. Effectiveness endpoints were measured at 3 and 9 months. Safety was evaluated according to adverse events (AE) and discontinuations of treatment.

Results Thirty-nine patients were included, 33 (85%) were women and 6 (15%) men. Mean age was 48 (23–74) years. Mean of prior preventive drugs was 6 (3–14), including: botulinum toxin A (n=39), topiramate (n=30), flunarizine (n=28), amitriptyline (n=27), zonisamide (n=26) and propranolol (n=24). Nineteen (49%) patients received galcanezumab 120 mg monthly (with 240 mg induction dose), 13 (33%) erenumab 70 mg monthly and 7 (18%) fremanezumab 225 mg monthly. Mean duration of therapy was 11 (4–22) months. Baseline monthly migraine days were ≥8 in all patients. At 3 months: 66% of patients presented both reduction in pain intensity and reduction ≥50% of monthly migraine days, 5% presented only reduction in pain intensity and 29% no response. At 9 months: 48% patients presented both reduction in pain intensity and reduction ≥50% of monthly migraine days, 10% presented only reduction in pain intensity and 42% no response. According to the safety profile, 8% patients presented injection site reactions as AE. No discontinuations of treatment were reported.

Conclusion and relevance CGRP-mAbs presented an adequate effectiveness in more than half of the patients at 3 months, although this effectiveness was slightly reduced at 9 months. CGRP-mAbs were well tolerated, with few AEs.

Conflict of interest No conflict of interest