The Efficacy and Safety of Different Dosages of Rituximab for Adults with Immune Thrombocytopenia: A Systematic Review and Meta-Analysis

Background. Rituximab has been frequently used as a second-line treatment for patients with immune thrombocytopenia (ITP). The optimal dose and course of rituximab are uncertain. Methods. A comprehensive search for randomized controlled trials reporting the use of low-dose (100 mg) or standard-dose (375 mg/m(2)) rituximab in ITP treatment was conducted. Meta-analyses were performed on CRR (complete response rate), ORR (overall response rate), PRR (partial response rate), SRR (sustained response rate), infection rate, SB (significant bleeding) rate, and SAE (serious adverse event) rate. Results. A total of 12 studies were included, comprising 869 patients. Compared to the control group, rituximab treatment resulted in an obvious increase in CRR (P < 0.00001), ORR (P < 0.0001), and SRR at month 6 and 12 (P = 0.0007, P = 0.0003), without increasing the infection rate (P = 0.12) and SAE rate (P = 0.11). No significant differences in CRR (RR 1.61 vs. 1.42, P = 0.45), ORR (RR 1.26 vs. 1.49, P = 0.28), PRR (RR 1.25 vs. 1.00, P = 0.11), SRR at month 12 (RR 2.00 vs. RR 1.64, P = 0.54), infection rate (RR 0.85 vs. 1.46, P = 0.36), and SB rate (RR 0.14 vs. 1.19, P = 0.17) were found in subgroups of low dose and standard dose. Conclusion. Rituximab was effective and safe for adult patients with ITP. A low-dose rituximab regimen might be an effective alternative to the standard-dose regimen in ITP, as it showed similar CRR, ORR, and SRR at month 12 and was relatively safer with a lower cost.