Dual-mechanism preventive therapy in chronic migraine: an exploratory meta-analysis of onabotulinumtoxinA and anti-CGRP monoclonal antibody combination

Combination therapy with onabotulinumtoxinA and an anti-CGRP monoclonal antibody demonstrates clinically meaningful reductions in headache frequency, disability, and medication use across observational cohorts. Interpretation should remain cautious given high heterogeneity, the absence of controlled comparative designs, and limited subgroup data. Because dispersion measures were imputed in several studies, statistical precision may be overestimated, and effect sizes should be interpreted as approximate rather than definitive. Larger prospective studies are needed to clarify patient selection, durability of benefit, cost-effectiveness, and equity of access.