Brogan P, Yeung RSM, Cleary G, et al. - A phase IIa, international, open-label, single-arm study (PePRS: Pediatric Polyangiitis Rituximab Study) was conducted to evaluate safety, tolerability, pharmacokinetics, as well as efficacy of rituximab among pediatric patients suffering from granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA). During the initial 6-month remission induction phase, patients were administered 4 weekly intravenous rituximab infusions (MabThera/Rituxan), 375 mg/m ² body surface area, and glucocorticoids. A total of 25 new-onset or relapsing patients (GPA, 19 [76%]; MPA, 6 [24%]) were enrolled at 11 centers. It was noted that ≥ 1 adverse event, mostly Grade 1/2 and primarily infusion-related reactions, occurred in all patients; serious adverse events occurred in 7 patients and 31 infection AEs occurred in 17 patients. There were no deaths. Findings demonstrated the good tolerability as well as the effectiveness of rituximab in pediatric patients, and rituximab showed an overall safety profile in these patients that was comparable with that of rituximab-treated adult patients with GPA or MPA. Rituximab was shown to be related to a positive benefit-risk profile for use in pediatric patients experiencing active GPA or MPA.