Clinical adverse effects of natalizumab: Protocol for a meta-analysis of randomized double-blind placebo-controlled clinical trails.

BACKGROUND: Natalizumab (NAT), a humanized monoclonal antibody, which binds in both α4ß1 integrins and α4ß7 integrins, is approved for the treatment of multiple sclerosis (MS) and Crohn's disease (CD). An uncommon but serious adverse event from NAT treatment is known as progressive multifocal leukoencephalopathy (PML). However, clinical comprehensive safety evidence of NAT is limited. METHODS: We will search Medline, Embase, Cochrane library, and ClinicalTrials.gov website from inception to May 9, 2018. Double-blind, randomized placebo-controlled trials reporting safety data of NAT will be eligible for inclusion. Outcome variables will include adverse events (AEs) varying degrees and AEs occurring in ≥ 5% patients with NAT or placebo. STATA software (version 12, Statacorp, College Station, TX) will be utilized to assess risk of bias and synthesize data. Outcomes will be reported by weight mean difference (WMD), risk ratios (RRs), and their 95% confidence intervals (95% CIs). I statistic will be used to evaluate heterogeneity among studies. RESULTS: This systemic review and meta-analysis will evaluate serious AEs and AEs of NAT as compared to placebo. CONCLUSION: Our study will provide a comprehensive picture of AEs of NAT.