We aimed to compare the efficacy and safety of the original product (OP) and biosimilar product (BP) of adalimumab in pediatric rheumatic diseases.The study group consisted of patients who had received original or biosimilar adalimumab (ABP 501) therapy for at least 3 months. The patients were divided into uveitis and arthritis groups based on the indication of adalimumab treatment. Assessment of disease activity was performed by Juvenile Arthritis Disease Activity Score in patients with juvenile idiopathic arthritis, and by standardization of uveitis nomenclature criteria in patients with uveitis.The study included 140 patients, of which 87 were treated with OP and 53 with BP. In the arthritis group, 26 (63.4%) and 20 (57.1%) patients reached inactive disease according to JADAS-27 in the original and biosimilar adalimumab groups, respectively. In the uveitis group the mean number of exacerbations throughout the treatment period was 0.84 ± 1.07 in the OP group, and 0.58 ± 0.79 in the BP group. There were 71 treatment-emergent adverse events in the OP group and 38 in the BP group.There was no significant difference between the biosimilar and the original product in efficacy and safety.
