Rituximab More Effective than Splenectomy for the Second-Line Treatment of Pediatric ITP

A study published in the Journal of International Medical Research suggested that there is evidence, though low quality, that rituximab (Rituxan) may be a more effective second-line therapy than splenectomy for children with immune thrombocytopenia (ITP).

However, the efficacy and safety of these finds need to be confirmed by further high-quality clinical trials, such as randomized controlled trials.

Notably, because pediatric ITP has a good chance of resolving spontaneously, and splenectomy presents a higher risk of infection than treatment with rituximab, the American Society of Hematology (ASH) guideline panel currently recommends using rituximab rather than splenectomy as the second-line treatment in children with ITP following first-line therapy failure.

“Because of the small number of clinical trials available, most of which were single-arm studies, we obtained data from only five clinical trials showing that [rituximab] has a therapeutic effect on pediatric ITP,” the authors wrote. “However, some heterogeneity was found in our studies, and we hope that more clinical trials will be conducted to further explore the results.”

In this study, researchers reviewed prospective clinical trials of rituximab for the treatment of pediatric ITP by searching the PubMed, Cochrane Library, Web of Science, and OVID: EMBASE databases, as well as ClinicalTrials.gov. To determine the efficacy and safety of rituximab, overall response (OR), complete response (CR), partial response (PR), sustained response (SR), relapse, and adverse drug reaction (ADR) rates were examined.

Across a total of 5 studies, which included 100 patients, the pooled OR, CR, PR, SR, relapse, and ADR rates were 52% (95% CI, 0.36-0.77; P < .01, I2 = 78%), 52% (95% CI, 0.41-0.67; P = .14, I2 = 45%), 18% (95% CI, 0.10-0.33; P = .21, I2 = 33%), 43% (95% CI, 0.29-0.63; P = .46, I2 = 0%), 25% (95% CI, 0.06-0.96; P = .15, I2 = 52%), and 30% (95% CI, 0.15-0.58; P = .06, I2 = 64%), respectively.

Importantly, the different ADR rates observed in this study indicate that rituximab therapy should be initiated cautiously for pediatric patients with ITP. Moreover, in addition to the standard dose, some studies also reported that a low dose (100 mg flat dose weekly for 4 weeks) or 2 fixed doses (1000 mg on days 1 and 15) of rituximab was effective for ITP.

To assess the safety of rituximab, researchers also calculated the incidence of adverse events (AEs) in 3 studies, which was 30%. In the included trials, the most commonly reported AEs were serum conditions such as decreased IgM or depletion of peripheral B-cells. Additionally, 1 trial showed that itching and scratching occurred in patients during rituximab infusion. Fortunately, the AEs observed were mild and reversible in most cases.

“According to this meta-analysis, although the quality of individual studies was not high, [rituximab] as a second-line agent results in a good treatment response in children with ITP,” the authors wrote. “Pediatric ITP has a low risk of bleeding, and the rate of severe bleeding in children was only 20.2%; however, the small number of patients makes high-quality research difficult. Additional controlled prospective trials are urgently needed to verify the efficacy and safety of [rituximab].”

Reference:

Qu M, Zhou J, Yang S, Zhou Z. Efficacy and safety of rituximab for minors with immune thrombocytopenia: a systematic review and meta-analysis. Journal of International Medical Research. doi: 10.1177/0300060520962348