Efficacy and Safety of Thrombopoietin Receptor Agonists in Patients with Primary Immune Thrombocytopenia: A Systematic Review and Meta-analysis

Immune thrombocytopenia (ITP) is an autoimmune disease characterized by increased platelet destruction and impaired platelet production. In this study, we conducted a systematic review and meta-analysis to determine the efficacy and safety of thrombopoietin receptor agonists (TPO-RAs) in primary ITP patients. Thirteen randomized controlled trials were included in this study, the pooled results of which demonstrated that TPO-RAs significantly increased platelet response (R) and durable response (DR) rates [risk ratio (RR): 2.77, 95% confidence interval (CI): 2.01-3.82, P = 5.9 × 10; RR: 7.52, 95% CI: 3.94-14.35, P = 9.2 × 10; respectively] and that TPO-RAs significantly reduced the incidences of any or severe bleeding events (RR: 0.80, 95% CI: 0.67-0.95, P = 0.013; RR: 0.52, 95% CI: 0.27-0.99, P = 0.048; respectively). Moreover, our results indicated that there was a significant reduction in the proportion of patients needing rescue medications in the TPO-RA groups compared with the control groups (RR: 0.50, 95% CI: 0.42-0.59, P = 2.0 × 10) and that the rates of any or severe adverse events were similar between the TPO-RA and control regimens (RR: 1.01, 95% CI: 0.92-1.10; RR: 0.74, 95% CI: 0.54-1.01; respectively). These findings demonstrate that TPO-RAs are an effective and safe second-line treatment option for primary ITP patients.