Why carry out this study?

Chronic migraine is a highly disabling condition, and many patients do not respond to initial preventive therapies, creating an unmet need for effective strategies.

OnabotulinumtoxinA and erenumab both target CGRP-related mechanisms, raising the question of whether switching after the initial therapy failed offers clinical benefit.

What was learned from this study?

Approximately 18% of patients experienced a ≥ 50% reduction in monthly headache days after switching treatments, with no significant difference between onabotulinumtoxinA-to-erenumab and erenumab-to-onabotulinumtoxinA sequences.

While the overall response rate was modest, findings suggest that treatment switching may be beneficial for a subset of patients.

The results underscore the need for personalized treatment strategies and highlight the importance of identifying biomarkers or clinical predictors of response in future prospective studies.