Real-World Effectiveness of Calcitonin Gene-Related Peptide-Binding Monoclonal Antibodies for Migraine Prevention: A Systematic Review.

Background:Migraine is a neurological disease with a high incidence. The new anti-calcitonin gene-related peptide monoclonal antibodies (anti-CGRP mAbs) have demonstrated effectiveness in preventing episodic and chronic migraine. Objective:To collect evidence of the real-world effectiveness of anti-CGRP mAbs by assessing outcomes such as reduction in monthly migraine days (MMDs), reduction in monthly headache days (MHDs), and percentage of patients having a 50% reduction in MMDs. Data Sources:The PubMed database was searched for the period from inception to October 20, 2021. Study Selection and Data Extraction:Of interest for this review were studies that evaluated the real-world effectiveness of anti-CGRP mAbs in terms of MMDs and reduction in MHDs. The search terms included "migraine", "monthly migraine days", and various drug names. The data are reported in terms of patients' baseline characteristics and treatment effectiveness. Data Synthesis:A total of 46 studies were evaluated, of which 30 (enrolling a total of 4273 patients across 10 countries) were included in the systematic review. The greatest absolute reduction in MMD was from 20.4 at baseline to 10.7 after 3 months of treatment. After 6 months, the greatest absolute difference was 10, relative to baseline. The largest absolute reduction in MHD at 3 months was from 22 to 8, whereas at 6 months, the greatest absolute reduction in MHD was 13. The treatment could be considered clinically effective (≥ 50% reduction in MMDs) for 41% of patients at 3 months and about 44% of patients at 6 months. Conclusions:Despite substantial variability in baseline values, this review confirmed the effectiveness of anti-CGRP mAbs, which yielded important clinical reductions in both MMDs and MHDs.