Fremanezumab for the Treatment of Migraine Complicated by Medication Overuse: A Systematic Review

Background Monoclonal antibodies targeting the calcitonin gene-related peptide (CGRP) pathway, such as fremanezumab, are effective for migraine prevention. However, their effectiveness in treating migraine complicated by medication overuse, remains underexplored. Objective This systematic review aims to evaluate the effectiveness of fremanezumab in adults with migraine complicated by medication overuse. Methods We systematically searched PubMed and Embase (Ovid) databases for studies on fremanezumab, selecting primary studies that included adults with migraine complicated by medication overuse and reported at least one efficacy outcome. The search was performed in January 2024 and then updated in June 2024. Risk of bias for randomized controlled trials was assessed using the Cochrane Risk of Bias 2 (RoB 2) tool, while real-world studies were evaluated using both the ROBINS-I and ROB-ME tools. Data extraction and analysis followed established guidelines. Results Our search identified 176 records, of which 2 clinical trials and 7 real-world studies were included. Included studies recruited a total of 1422 adults with migraine complicated by medication overuse. In post hoc analyses from clinical trials, fremanezumab significantly reduced monthly migraine days, days with acute headache medication use, and Headache Impact Test (HIT-6) scores compared to placebo during a 12-week period. The real-world studies reported a reduction in monthly headache days at 6 months, and a high reversion rate from medication overuse headache (MOH) after one year of treatment. Conclusion Both post hoc analyses from clinical trials and real-world studies support fremanezumab benefits in reducing migraine frequency, medication use, and headache-related disability in adults with migraine complicated by medication overuse. Given the limited quality of data, further real-world research with standardized reporting criteria is needed to substantiate long-term benefits and establish optimal treatment protocols.