Rituximab (anti-CD20 monoclonal antibody) in children with chronic refractory symptomatic immune thrombocytopenic purpura: efficacy and safety of treatment.

This retrospective study investigated the effects of rituximab in 19 pediatric patients (15 girls and 4 boys) with chronic refractory symptomatic immune thrombocytopenic purpura (ITP). Patients received from 2 to 5 weekly infusions of rituximab (375 mg/m(2)); 15 patients were younger than 12 years when treated. The median follow-up time was 30 months (range, 9-43 months). The overall response rate was 68% (13/19 patients). Six responders relapsed at a median of 4.5 months (range, 3-8 months). Seven patients still displayed a platelet count >150,000/microL at a median of 33 months (range, 14-43 months) after rituximab treatment. Six of 15 patients treated with 4 or 5 weekly infusions and 1 of 4 patients treated with 2 or 3 infusions are still in remission. No difference was detected between splenectomized and nonsplenectomized patients. The duration of ITP disease at the time of treatment did not influence the response rate. Patients still in remission showed significantly lower levels of CD19+ cells after 4 and 6 months than nonresponding or relapsed patients (P < .05). No major infections were reported during follow-up. Our data show the efficacy and tolerability of rituximab in young children with refractory symptomatic ITP. Nonrelapsed patients showed a more prolonged B-cell depletion.