A systematic review and meta-analysis of safety and efficacy of safinamide for motor fluctuations in patients with Parkinson's disease

Background: Safinamide, a recently developed drug with several mechanisms of action has been investigated as an add-on therapy for Parkinson's disease patients suffering from motor complications due to the usage of anti-Parkinson's medications such as levodopa and dopaminergic drugs. The aim of the study is to investigate the efficacy and safety of Safinamide as add-on therapy for Parkinson's disease patients. Methods: A computerized literature search was conducted of PubMed, EMBASE, ClinicalTrial.gov and Cochrane Library until August 2019. We selected relevant randomized controlled trials comparing safinamide groups to placebo groups. Relevant outcomes were pooled as mean difference (MD) and risk ratio (RR) using Review Manager 5.3. Results: We found that the overall MD of changes in “off-time” and “on time without troublesome dyskinesia” favored the safinamide group over the placebo group (MD -0.72 h, 95% CI -0.89 to -0.56 and MD 0.71 h, 95% CI 0.52 to 0.90, respectively). Additionally, the overall MD of change in Unified Parkinson's Disease Rating Scale part three (UPDRS III) favored the safinamide group (MD -1.83, 95% CI -2.43 to -1.23). In case of adverse events, the pooled meta-analysis did not favor the safinamide group over the placebo group. Conclusions: In this study, we provide class I evidence about the potential role of safinamide as an add-on therapy for Parkinson's disease patients suffering from motor fluctuations. However, a few included studies did not mention the data of important outcomes. Also, we report high risk of bias in individual studies. Future randomized controlled trials with different doses are recommended to provide more evidence for the efficacy and safety of safinamide as a treatment for motor complications of anti-Parkinson's medications.