Effects of long‐term etanercept treatment on growth in children with selected categories of juvenile idiopathic arthritis

Objective To evaluate the effects of long‐term etanercept treatment, with or without methotrexate, on growth in children with selected categories of juvenile idiopathic arthritis (JIA). Methods We conducted a 3‐year, open‐label, nonrandomized registry of 594 patients with polyarticular or systemic JIA treated with etanercept only, etanercept plus methotrexate, or methotrexate only. Height, weight, and body mass index (BMI) were assessed at baseline and at years 1, 2, and 3, using percentiles derived from US Centers for Disease Control and Prevention standardized growth charts. Results Statistically significant increases in the mean height percentiles from baseline were observed in etanercept‐treated patients at year 3 (4.8 percentile points) and in patients treated with etanercept plus methotrexate at years 1, 2, and 3 (2.4, 3.3, and 5.6 percentile points, respectively). Statistically significant increases from baseline in the mean weight percentiles were observed at years 1, 2, and 3 in both the etanercept group (7.4, 10.0, and 13.0 percentile points) and the etanercept‐plus‐methotrexate group (2.9, 6.9, and 8.4 percentile points, respectively). Statistically significant increases from baseline in the mean BMI percentiles were observed in both the etanercept group (range 9.6–13.8 percentile points) and the etanercept‐plus‐methotrexate group (range 2.1–5.2 percentile points). The mean height, weight, and BMI percentiles did not change significantly in patients in the methotrexate‐only group. Conclusion Etanercept treatment, with or without methotrexate, may contribute to the restoration of normal growth in children with JIA.