Efficacy and Safety of CGRP Monoclonal Antibodies for the Prevention of Migraine Compared with Placebo: A Systematic Review and Meta-Analysis

Abstract Background: Calcitonin gene-related peptide monoclonal antibodies (CGRP mAbs) are a novel class of drugs for migraine that includes erenumab, fremanezumab, galcanezumab and eptinezumab. In clinical trials, CGRP mAbs have been reported to show good efficacy in the prevention of episodic migraines or chronic migraines. Our aim was to evaluate the efficacy and safety of CGRP monoclonal antibodies in this study.Methods: We systematically searched for randomized controlled trials in the PubMed, Embase, ClinicalTrials.gov, and Cochrane Library databases. The primary outcome was overall mean change from baseline to end of treatment in the number of monthly migraine headache days (MMHDs). The secondary outcomes included 50% response rate, in the number of monthly headache days (MHDs), in the number of monthly headache hours (MHHs), and in the number of monthly acute migraine-specific medication days (MSMDs). The safety outcomes were evaluated in terms of reported adverse events. Results: Eighteen studies including 11,099 patients were included in the meta-analysis. The meta-analysis showed that CGRP mAbs exhibited a significant benefit in reducing the number of MMHDs compared to placebo (Episodic migraine: Std. MD -0.42, 95% CI -0.47 to -0.36; Chronic migraine: Std. MD -0.28, 95% CI -0.35 to -0.21). Similarly, CGRP mAbs were superior to placebo in the secondary outcomes of 50% response rate, MHDs, MHHs, and MSMDs. With respect to safety, serious adverse events and withdrawal due to adverse events were not significantly associated with CGRP mAbs. Fremanezumab was associated with a significantly higher incidence of any adverse event compared with placebo (RR 1.10, 95% CI 1.03 to 1.17). Galcanezumab was associated with significantly higher treatment-emergent adverse events compared with placebo (RR 1.11, 95% CI 1.04 to 1.17). Constipation and injection site pain were significantly higher with erenumab than placebo. Injection site erythema and injection site induration were significantly higher with fremanezumab than placebo. Upper respiratory tract infection, injection site erythema, injection site pruritus and injection site reaction were significantly higher with galcanezumab than placebo. Conclusions: This study confirms that CGRP mAbs are effective as preventive treatments for episodic migraines and chronic migraines. Adverse reactions at the injection site were associated with erenumab, fremanezumab and galcanezumab therapy. Constipation was more common with erenumab. The risk of upper respiratory tract infection was higher with galcanezumab.Systematic review registration: Our PROSPERO protocol registration number: CRD42019125928. Registered 26 November 2019.