Switching of monoclonal antibodies against the calcitonin gene-related peptide or its receptor in migraine. Results from a Spanish Cohort.

Background Switching between calcitonin gene-related peptide(CGRP) monoclonal antibodies(mAbs) may be a beneficial strategy after discontinuation. The aim of this study was to evaluate switching outcomes of effectiveness/tolerability. Methods Retrospective multicentric study of migraine patients who switched to another CGRP-mAb due to lack of tolerability or effectiveness (defined as <30% reduction of monthly headache days[MHD]). Assessment was performed before and three months after switch. The main outcome was the response rate of MHD. Secondary outcomes included other effectiveness/tolerability measures. Results 90patients were included: 75(83.3%) women, 72(80%) chronic and 18(20%) episodic migraine. Mean age was 45.9 ± 11 years and mean duration of migraine was 29.2 ± 12.4 years. Mean time under first mAb prior to switch was 10.4 ± 4.9 months. Most frequent switches were erenumab-galcanezumab 38(42.2%) and erenumab-fremanezumab 21(23.3%). Lack of effectiveness (50/90, 55.6%) or tolerability (40/90, 44.4%) provoked switching. Most common adverse events(AEs) leading to discontinuation were constipation and flu-like syndrome in 16(40%) patients each. RR of MHD 30–50% occurred in 10 patients(11.1%), ≥50% in 32(35.6%) and < 30% in 48(53.3%). Significant reduction was proved after switch in MHD (20[IQR:15–29] vs 13[IQR:7–23];p < 0.001) and MMD (15[IQR:12–20] vs 10[IQR:7–16];p < 0.001). After switching, 38(42.2%) experienced AEs, but tolerability improved in 50% of patients who discontinued due to lack of tolerability. RR compared between switches to different CGRP-mAb classes showed no differences. Conclusion Switching may become an individualized strategy in migraine refractory patients who discontinue CGRP-mAbs due to lack of effectiveness/tolerability. In this study, supportive data are provided to the growing evidence of switch and future needs are highlighted.