208 Long-term efficacy of erenumab in patients with chronic migraine who failed ≥3 prior prophylactic treatments

Objective Erenumab is a fully human monoclonal antibody. Following a 12-wk double-blind (DB), placebo- controlled chronic migraine (CM) study, a 52-wk open-label extension (OLE) study assessed long-term efficacy and safety of erenumab. We report the long-term efficacy of erenumab in a subgroup of patients in the OLE who failed ≥3 prior prophylactic treatments due to lack of efficacy and/or poor tolerability before enrolment in the parent study. Methods During the 52-wk OLE patients received erenumab every 4wks. Following a protocol amendment, patients who had not reached wk28, had a dose increase to 140mg to allow them to receive the higher dose for ≥6 months; patients completing wk28 visit remained on 70mg throughout OLE. OLE treatment phase data were summarised by visit for all pts (combined treatment groups). Results Of 605 pts enrolled in the OLE, 226 had ≥3 prior prophylactic TFs. Mean(SD) MMD at baseline for the TF subgroup was 18.95(4.2);overall,18.11(4.5). At wk52, erenumab treatment resulted in a sustained reduction in MMD from baseline(TF,−7.94[6.5];overall,−9.29[6.6]) and 47% of pts in the ≥3 TF subgroup achieved ≥50% response. Conclusion Erenumab treatment resulted in sustained efficacy in pts with ≥3 TF, a difficult-to-treat popula- tion, with greater efficacy for 140mg vs 70mg. 13m6ark.weatherall1@nhs.net