Systematic review: efficacy and safety of rituximab for adults with idiopathic thrombocytopenic purpura.
Background: Rituximab, a monoclonal anti-CD20 antibody, is increasingly used to treat idiopathic thrombocytopenic purpura (ITP).
Objective: To systematically review the literature on the efficacy and safety of rituximab for the treatment of adults with ITP.
Methods: MEDLINE, EMBASE, the Cochrane Library, abstracts from the American Societies of Hematology and Clinical Oncology annual meetings, and bibliographies of relevant articles and reviews were searched in duplicate until April 2006. Methods: Descriptive and comparative studies in any language that met predefined inclusion criteria were eligible. Efficacy analysis was restricted to studies enrolling 5 or more patients. Methods: Platelet count response, toxicities, dose, previous treatments, baseline platelet count, duration of ITP, study design, and sources of funding were extracted in duplicate.
Results: We identified 19 eligible reports on efficacy (313 patients) and 29 on safety (306 patients). Weighted means for complete response (platelet count > 150 x 10(9) cells/L) and overall response (platelet count > 50 x 10(9) cells/L) with rituximab were 43.6% (95% CI, 29.5% to 57.7%) and 62.5% (CI, 52.6% to 72.5%), respectively. Responses lasted from 2 to 48 months. Nearly all patients had received corticosteroids, and 53.8% had undergone splenectomy. Nine patients (2.9%) died.
Conclusions: There were no controlled studies, and no studies met all criteria for study quality. Reported deaths could not necessarily be attributed to rituximab. Overall, the number of rituximab-treated patients with ITP reported in the literature is small. Conclusions: Rituximab resulted in an overall platelet count response in 62.5% of adults with ITP. However, this finding derives from uncontrolled studies that also reported significant toxicities, including death in 2.9% of cases. These data suggest that providers should avoid indiscriminate use of rituximab and that randomized, controlled trials of rituximab for ITP are urgently needed.