Background and Importance Galcanezumab is a recombinant humanised monoclonal antibody that binds to calcitonin gene-related peptide (CGRP). It is used for the prophylaxis of chronic migraine in adults due to It has demonstrated its safety and effectiveness in reducing the frequency of episodes and improving patient functionality in the EVOLVE-1, EVOLVE-2 and REGAIN studies. However, there is no evidence on its effectiveness, tolerance and causes of treatment limitation in a real-world data.

Aim and Objectives To describe the frequency of discontinuations of treatment with galcanezumab and evaluate the causes responsible for these suspensions in our patient cohort.

Material and Methods Observational, retrospective and descriptive study developed with patients diagnosed with migraine who have received treatment with galcanezumab and it has already been suspended at the time of the study (September 2023) under follow-up by the pharmacy service of a tertiary hospital (years 2020–2023). Variables collected: demographic (sex and age) and clinical (duration of treatment with galcanezumab, diagnosis, monthly migraine episodes, previous treatments, rate reasons for discontinuation: low effectiveness, defined by a reduction below 50% in migraine attacks, intolerance and personal decision).

Results 110 patients were studied, all of them with a diagnosis of chronic migraine. 76.5% women. Mean age: 44.7 years (22–75).

Mean number of previous migraine episodes over 8 months. All of our patients had received previous treatment with three or more treatments (beta blockers, antiepileptics, antidepressants and botulinum toxin) without satisfactory experience.

17 patients discontinued treatment with galcanezumab in our hospital during the study period (15.5%). Suspension rates: 64.7% low effectiveness; 29.4% intolerance (local reaction: two patients; weight gain: one; constipation and generalised itching: one); 5.9% personal decision (upcoming pregnancy).

Conclusion and Relevance Galcanezumab has had a low dropout rate in our patients, making us consider it a safe drug in our cohort.

The percentage of suspensions due to drug intolerance has been very low, compared to the pivotal trials in which it represented the most frequent cause (mainly local reactions to the injection).

In routine clinical practice, we continue to monitor side effects of our patients.

Conflict of Interest No conflict of interest.