Efficacy of Erenumab in Patients With Treatment-Resistant Chronic Migraine and Medication Overuse Headache

Objective: To evaluate the efficacy and safety of erenumab, a monoclonal antibody that targets the calcitonin gene-related peptide (CGRP) receptor, in patients with treatment-resistant chronic migraine and medication overuse headache. Methods: A single-center, retrospective observational study conducted at University Medical Center on 73 patients with both medication-overuse headache and treatment-resistant chronic migraine who failed at least three oral preventive medications and/or botulinum toxin injections. Clinical data were extracted from the medical records and patient interviews. The patients received monthly erenumab injections 70 mg. Key outcomes included monthly migraine days, headache severity (visual analog scale VAS), headache impact test (HIT-6), acute medication use, and global impression of change (PGIC) over a 3-month follow-up period. Results: Significant reductions were observed in monthly migraine days (mean: 12.3 days, p<0.001), HIT-6 scores (mean: 21 points, P <0.001), headache severity (VAS score reduction: 6.1, P <0.001), and acute medication use (mean: 14.8 days, P <0.001). Most patients reported a ``very good'' or ``good'' improvement with minimal side effects. Conclusion: Erenumab demonstrated substantial efficacy and safety in reducing the frequency and severity of chronic migraine with medication overuse, improving the quality of life, and decreasing acute medications use. These findings support its role as a valuable therapeutic option for this challenging condition.