Biosimilars Versus Originators in Children With Juvenile Idiopathic Arthritis: A Real-World Experience

Introduction: We aimed to evaluate the efficacy, safety, and immunogenicity profile of Etanercept (ETA) and Adalimumab (ADA) biosimilars (BIOs) compared to their originators in children with juvenile idiopathic arthritis (JIA). Method: Eighty-one JIA children treated with ETA or ADA originators or BIOs were examined at baseline (T0) and after 3- (T1), 6- (T2), 12- (T3), and 24-(T4) months after starting treatment. Results: Lower Juvenile Arthritis Disease Activity Score 10 (JADAS-10) scores were reported at T1, T2, T3, and T4 in JIA children treated with BIOs than originators (all p < 0.05). At T1 and T3, anti-drugs antibodies levels were lower in children receiving BIOs than originators (p = 0.04 and p = 0.0007, respectively), even after adjustments (both p < 0.05). Relapses were lower for BIOs compared to originators (p < 0.001). Safety profile was comparable between the groups (p > 0.05). Discussion: A better overall profile of BIOs than originators was demonstrated in JIA children, but larger confirmatory studies are needed.