4CPS-051 Evaluation of the response of monoclonal antibodies against migraine after the application of a treatment interruption protocol

<h3>Background and Importance</h3> Monoclonal antibodies targeting the calcitonin gene-related peptide (CGRP) ligand or its receptor are available for migraine prevention. European guidelines suggest discontinuing monoclonal antibody therapy after 12–18 months, although treatment can also be continued if deemed necessary. <h3>Aim and Objectives</h3> To establish the effectiveness of antibodies CGRP in the treatment of migraine and to analyse the response to retreatment in patients who discontinued therapy after 1 year of treatment. <h3>Material and Methods</h3> Observational and retrospective study. All patients who initiated treatment between August 2020 to June 2024 were included. Demographic data were collected (age, sex), clinical variables (type of migraine) and pharmacotherapeutic variables (type of monoclonal antibody, switch). Treatment effectiveness was calculated as the mean number of monthly migraine days (MMD) and the reduction ≥50% of MMD. According to our centre’s protocol, these treatments should be withdrawn after 1 year. Response was assessed after 1 year of treatment and evolution after withdrawal (resumption of treatment versus maintenance of response) and 3 months after restarting treatment. Response was analysed in patient subgroups: type of migraine, type of antagonist and time to reintroduction. The statistical software SPSS v. 25 was used for the analysis. <h3>Results</h3> Fifty-five patients were included, of whom 90.9% (n=50) were women. Median age: 47 years (38–55). 72.7% of patients (n=40) had chronic migraine. The effectiveness results are detailed in table 1. 27.3% (n=15) required a change of treatment due to ineffectiveness. 70.9% (n=39) achieved a ≥50% reduction in MMD (p=0.005). 34.5%(n=19) did not need to restart treatment with a median maintenance of response of 9.5 months (3–15), while 58.2% (n=32) of patients were reintroduced due to clinical deterioration. After restart, 53.1% (n=17) achieved a ≥50% reduction in MDD (p=0.102). Regarding the response of the different subgroups of patients requiring reintroduction, no significant differences were found. <h3>Conclusion and Relevance</h3> Half of the patients requiring reintroduction of treatment achieve the goal within 3 months. One third of patients maintain response after 1 year of treatment. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest