Thrombopoietin receptor agonists and rituximab for treatment of pediatric immune thrombocytopenia: A systematic review and meta-analysis of prospective clinical trials

Background Children with immune thrombocytopenia (ITP) may require second-line ITP therapies. The high remission rate in pediatric patients, need for extended-duration use of thrombopoietin receptor agonists (TPO-RAs), drug adherence, potential side effects, monitoring, and cost effectiveness are factors that should be considered in decision-making about second-line therapies. Rituximab (RTX) has been used off-label for years to treat ITP but there are limited studies about its efficacy and safety in children. To date, no studies have directly compared TPO-RAs with RTX for the treatment of childhood ITP. Methods This systematic review analyzed the overall platelet response, durability of treatment effect, and safety for RTX use in comparison to TPO-RAs in pediatric ITP. MEDLINE/PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched through December 2020 and meta-analysis was conducted using proportions of success/failure for each intervention in the selected studies. Results The proportion of participants achieving the primary endpoint of a platelet response above 50,000 was similar for TPO-RAs (proportion = 0.71, 95% CI: 0.63-0.78) and RTX (proportion = 0.68, 95% CI: 0.53-0.82). However, considerable variation was found between the two groups with regards to the sustainability of the response and other secondary outcomes such as need for rescue and adverse events. RTX was associated with higher rates of rescue therapy. Conclusions In this analysis of prospective pediatric ITP studies, RTX and TPO-RAs had similar rates of overall platelet response but differed in other important measures. Prospective comparative studies are needed to better characterize second-line treatments for pediatric ITP.