Erenumab and galcanezumab in chronic migraine prevention: effects after treatment termination

BACKGROUND: Monoclonal antibodies (mAbs) targeting the CGRP pathway are safe and efficacious therapies for the prevention of migraine. In this study we assessed the effects of discontinuation of preventive erenumab and galcanezumab treatment in patients with chronic migraine. METHODS: This retrospective pooled analysis included completers of the open-label extension study phase for the preventive treatment of chronic migraine with galcanezumab (NCT02614261; 9 months) and erenumab (NCT02174861; 12 months) in a single headache center. We compare migraine data until week 12 after open-label treatment completion, when patients did not have any pharmacological preventive medication, to study baseline values of the double-blind trial period, and to the last 4 weeks of the open-label extension. The assessment included changes in monthly migraine days, headache hours, days with severe headache and acute headache medication use. RESULTS: Data from 16 patients after galcanezumab (n = 9) and erenumab (n = 7) open-label treatment completion were analyzed. The mean number of monthly migraine days was 18.38 ± 3.74 at baseline, and 12.19 ± 4.53 in the last 4 weeks of the open-label extension (p < 0.001). Monthly migraine days remained significantly reduced compared to baseline during the entire 12-week observation period after open-label termination (p = 0.002), with a reduction of 5.38 ± 4.92 in weeks 1–4 (p = 0.001), 4.75 ± 4.15 in weeks 5–8 (p = 0.001), and 3.93 ± 5.45 in weeks 9–12 (p = 0.014). There was no significant difference in monthly migraine days between the 12 weeks after open-label termination and the last 4 weeks of the open-label phase (p = 0.228). All other analyses revealed numerical improvement through week 12 in comparison to baseline. CONCLUSIONS: In this small, self-selected cohort, the results indicate a therapeutic effect of monoclonal antibodies targeting the CRGP pathway in chronic migraine prevention after treatment termination up to 12 weeks.