Effect of Tocilizumab on growth impairment in systemic juvenile idiopathic arthritis with long-term corticosteroid therapy

Abstract

Background. The safety and efficacy of tocilizumab (TCZ), an anti-IL-6 receptor monoclonal antibody, have been reported in the treatment of children with systemic juvenile idiopathic arthritis (sJIA).Objectives. Growth of children during the TCZ study was analyzed.Methods. Forty-five sJIA patients (8.1 ± 4.2 years) were enrolled. Mean standard deviation score (SDS) for height (HTSDS), height velocity (HVSDS) and changes in SDS from baseline (∆SDS) were determined. Correlation between ∆SDS and several factors such as age, disease duration and corticosteroid exposure were evaluated. Yearly height velocity was analyzed for 28 patients for whom we had data for 1 year prior to TCZ administration and who had received TCZ for more than 1 year.Results. Of the 45 patients, 38 (84%) obtained a clinical response at week 144. The mean baseline HTSDS was − 2.7 ± 2.0 and inversely correlated with disease duration. Significant improvement was seen in change in HVSDS from 1 year prior to 1 year after baseline (− 6.0 ± 4.0 to − 2.5 ± 3.9, p = 0.0064). Reduction in corticosteroid exposure was significantly associated with improvement in HVSDS (p = 0.0027).Conclusions. Growth impairment evidenced by HTSDS was more prominent in patients with longer standing disease. Catch-up growth was observed in patients who required less or no corticosteroid during TCZ treatment.