CALCA and migraine disorder: Efficacy in MOH patients was also reported for onabotulinumtoxinA (BoNT-A) in a subanalysis of the pooled PREEMPT trials [39], but in a meta-analysis [40] this was true for reduction in monthly migraine days (MMDs) but not for response rate and the effect size of anti-CGRP/rec mAbs was greater, and drop-out rates were lower than those of BoNT-A.