OnabotulinumToxinA Reduces Pharmacological Burden in Chronic Migraine Patients: A Two-Center Prospective Cohort Study

Background: Chronic migraine (CM) is a highly disabling and difficult-to-manage condition with a high pharmacological and economic burden. OnabotulinumtoxinA (BTx) was the first treatment specifically approved for CM. The main aim of this study was to assess whether the initiation of BTx is associated with discontinuation of previously prescribed preventive therapies. Methods: This study was a prospective cohort investigation conducted in two headache centers: Carlo Besta (Milan) and Policlinico Campus Bio-Medico (Rome). We included patients with CM and previous oral preventive treatments initiating BTx. We analyzed persistence with preventive therapies over 12 months of follow-up and evaluated the conversion rate from chronic to episodic migraine (EM), along with change in migraine days, symptomatic intake, and HIT-6. Results: A total of 95 patients were included in the main analysis, showing a discontinuation of treatment in 28.4% of patients at 12 months. In the exploratory analysis, a CM to EM conversion rate of 58.9% was achieved at 12 months; meanwhile, HIT-6, migraine days, and symptomatic intake showed a sizeable improvement. Conclusion: Treatment with BTx was associated with a reduction in drug burden at 12 months and a CM to EM conversion rate of almost 60% at 12 months, also contributing to a reduction in the economic burden of the disease.