06Adverse effects of rituximab used in children with idiopathic nephrotic syndrome. A multicentric retrospective study

Introduction Rituximab (RTX) is an effective alternative treatment for severe idiopathic nephrotic syndrome in children. Nevertheless, the actual indication of RTX within the therapeutic strategy remains controversial, given the lack of data on the safety of this treatment in this setting. Objective To retrospectively collect and describe all severe and significant adverse effects that had occurred in children treated with RTX for idiopathic nephrotic syndrome. Patients and methods All participating centres within the SNP network were asked to fill an online database for all their patients treated with RTX for INS. Data were collected from the patients’ medical charts. Severe or significant adverse effects were defined as follow: any event that led to (i) a vital risk, (ii) a hospitalization or a prolongation of hospitalization, (iii) the occurrence of sequelae or (iiii) the interruption of RTX therapy. Results Twenty-three centres participated to the study. In total, 196 cases were collected on October 10th. The mean age at diagnosis was 4.7 (± 3.2) years. The mean duration of disease was 7.5 (± 4.3) years when RTX was first used. The mean follow-up was 3.2 (± 2.5) years and 1.5 (± 1.7) years since the first and the last infusion of RTX respectively. Adverse effects were reported in 6.6% of cases during the infusion (dyspnea = 6, cardiac arrhythmia = 1, hemodynamic instability = 1, others = 7), and in 13.1% of cases after the infusion (in relation with neutropenia = 6, low IgM = 3, low IgG = 6, infectious disorder = 14, cardiac = 2, liver = 1, kidney = 1, digestive = 2, neurological = 2, others = 6, several complications can be present in the same patient). The main consequences of these adverse effects were: non-planned hospitalizations ( n  = 30), modifications or interruptions of RTX treatment ( n  = 6), significant invalidity ( n  = 3). A single adverse effect led to a life-threatening situation. Conclusion Adverse effects were reported in 18.9% of these 196 patients treated by RTX for INS. RTX treatment was interrupted or modified in 6 cases. Only 4 adverse effects led to severe consequences (either life threatening event or significant invalidity). These results will help to evaluate the benefit/risk ratio or RTX for INS in children. This is an ongoing study, therefore results can be different when they will be presented during the meeting.