Background/Purpose:  Rituximab (RTX) is a chimeric monoclonal antibody that specifically targets CD20 positive B cells and is used successfully for a variety of pediatric rheumatologic conditions. One pediatric autoimmune disease for which RTX has gained particular interest is systemic lupus erythematosus (SLE). Herein, we report on the safety and effectiveness of use of RTX in 104 subjects with a variety of pediatric autoimmune diseases, with a focus on SLE.

Methods: This was a retrospective study of children treated by 1 or more pediatric rheumatologists at Children’s of Alabama (CoA) with at least 1 course (2 doses of 750 mg/m², maximum of one gram, 2 weeks apart) of RTX between August 1, 2007 and April 1, 2014. To evaluate effectiveness, we documented for all patients the MD Global assessment of disease activity and corticosteroid dosage at baseline (just prior to RTX) and at 12 months of follow-up. For SLE patients, we additionally documented complement levels, ESR, CBC, creatinine, albumin, urine protein, and anti-DNA levels. For safety outcomes, we documented infusion reactions and severe adverse events. Comparisons were performed with the Student’s t-test.

Results: 104 children were included in the study.  The single most common diagnosis was SLE (n = 50), and the next most common diagnosis was dermatomyositis (n=11). In total, 464 RTX infusions were administered during the study period. A total of 251.4 person-years of follow-up was available (median 2.4 years; range 1 month – 6.4 years.) Among patients with one-year follow-up data available, mean daily corticosteroid dose decreased from 29.8 ± 25.7 mg to 8.7 ± 13.1 mg (n = 98; p < 0.001) and  mean MD global assessment of disease activity decreased from 34.4 ± 19.2 to 15.7 ± 12.3 (n = 88; p < 0.001). Among SLE patients with data available at 12 months of follow-up, significant improvements were observed in corticosteroid dosage and MD global assessment of disease activity, as well as in multiple SLE-associated markers of disease activity (Table.) Overall, RTX was well-tolerated. There were no infusion reactions requiring emergent intervention. The incidence of hospitalized infections among the cohort as a whole (83.5/1,000 person-years) and among the 50 SLE patients (92.2/1,000 person-years) is similar to previous studies of children with SLE treated with cyclophosphamide. One patient died after transition to adult care.

Conclusion: RTX can be safely administered to children with a variety of rheumatic conditions and appears to contribute to decreased disease activity and steroid burden.

Table. Effectiveness data among 48 SLE patients with at least 12 months of follow-up.