6ER-041 Switching calcitonine gene-related peptide monoclonal antibodies (CGRP mAb) in patients with refractory migraine: real-world data

<h3>Background and Importance</h3> There is growing evidence about the benefit of using a second CGRP mAb in patients with loss of response to one of them. We have clinical experience with patients who have used two or more CGRP mAbs. <h3>Aim and Objectives</h3> To assess the effectiveness of using other CGRP mAbs for the treatment of chronic migraine in patients who have already been treated with one of them. <h3>Material and Methods</h3> A retrospective, observational study in a third-level hospital. All patients who had received two or more CGRP mAbs from January 2020 to September 2024 were included. The data collected from the electronic health record and the prescribing software were: age, gender, baseline monthly migraine days and every 3 months, number of CGRP mAbs used for each patient and each treatment duration. Response to treatment was defined as a reduction of at least 50% of the baseline monthly migraine days. Treatment was interrupted when loss of response was detected in the quarterly visits. <h3>Results</h3> Forty patients: 75% female, median age 45 years (IQR 37–54), median baseline monthly migraine days 23 (IQR 16–30). 16 (40%) did not have response after 2 (n=5), 3 (n=8) or 4 (n=3) CGRP mAbs. 13 (32%) had treatment switches with good response: 2 patients were in treatment with 4 consecutive CGRP mAbs during 18 and 37 months respectively, achieving a reduction of 87% and 85% in baseline monthly migraine days; 2 patients with 3 consecutive CGRP mAbs during 50 and 27 months had a reduction of 78% and 73%; 9 patients were a median of 19 months (IQR 12–24) with one CGRP mAb and 11 months (IQR 7–12) with a second one, with a median reduction of 67% (IQR 63%-87%) in baseline monthly migraine days.11 (28%) had a reduction of 75% (IQR 65%-83%) in baseline migraine days during 15 months (IQR 9–21) (median values). They failed to 1 (n=7) or 2 (n=4) other CGRP mAbs. <h3>Conclusion and Relevance</h3> Our data suggest that switching CGRP mAbs might be an option for patients with many monthly migraine days when loss of optimal response is detected. On the other hand, patients with no response to one CGRP mAb may not respond to other ones. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest