Background and Importance Therapeutic options for migraine prevention in non-responder patients to monoclonal antibodies (mAbs) targeting Calcitonin Gene-Related Peptide (CGRP) and its receptor are often limited. There are no recommendations of switching between mAbs classes.

Aim and Objectives To assess the effectiveness and safety of mAb switching in non-responder migraine patients.

Material and Methods Retrospective observational study in a tertiary hospital (1-January-2021 to 31-July-2023). We included patients who received a first mAb for ≥3 months, were non-responders and switched to another mAb class. Patients were excluded if they switched due to side effects. Monthly headache days (MHD) were collected to assess the ≥50% responder rates and the absolute reduction of MHD at 3 months, as well as the absolute reduction of monthly acute medication days (AMD). Data were recorded from electronic medical records and patient interviews. The study was approved by the Ethics Committee. Informed consent was obtained.

Results We identified 110 patients who had received galcanezumab (n=57) and fremanezumab (n=53) as their first mAb. Of these, 24 (21,8%) switched to the CGRP-receptor mAb, erenumab. Of 105 patients treated with erenumab, 30 (28,6%) switched to a CGRP-ligand mAb. Three patients switched because of side effects, so 51 patients were included.

The ≥50% responder rate was 40% and 61,9% at 3 months with erenumab and CGRP-ligand mAb, respectively. MHD reduction: 17±7,4 to 13,8±8,7 and 16±7,7 to 8,4±6,1, respectively. AMD reduction: 16,1±9,9 to 15,4±10,2 and 11,7±9,2 to 7,6±7,3. Seven patients (35%) changed to a third mAb in patients that switched from ligand mAb to receptor mAb, 23,8% in the other group.

Conclusion and Relevance Switching seems to be a promising treatment option especially in migraine patients that switched from CGRP-receptor mAb to CGRP-ligand mAb. However, some of them need to switch to a third mAb. More studies are needed to describe which patients will respond to CGRP-mAb switching.

Conflict of Interest No conflict of interest.