Efficacy & safety of adalimumab biosimilar in axial spondyloarthritis: A retrospective study from a tertiary care centre in South India.

Background & objectives While originator anti-tumour necrosis factor (TNF) agents have demonstrated good efficacy in the management of axial spondyloarthritis, the therapeutic equivalence and safety profile of their Indian biosimilars remain uncharacterised. This study aimed to evaluate the efficacy and safety of adalimumab biosimilar in patients diagnosed with axial spondyloarthritis. Methods This retrospective, single-centre observational study from India assessed the efficacy and safety of adalimumab biosimilar in axial spondyloarthritis patients with high disease activity. We recorded baseline characteristics, swollen/tender joint counts, and Bath ankylosing spondylitis disease activity index (BASDAI) scores at 0, 12, and 24 wk. The primary outcome was the percentage of patients achieving a BASDAI50 response at 12 wk; adverse events were also monitored. Results The study included 96 axial spondyloarthritis patients (84 male, mean age 29.1 yr) and showed that adalimumab biosimilar was efficacious, with 54per cent achieving BASDAI50 response at 12 weeks and 70 per cent at 24 wk. Mean BASDAI significantly improved from 5.8 at baseline to 2.9 at 12 wk and 2.3 at 24 wk. Safety concerns were minimal, though two patients developed tuberculosis despite prophylaxis. Most patients accessed the biosimilar through government funding, and dose spacing was attempted in a few. Interpretation & Conclusions Adalimumab biosimilar is efficacious in patients with axial spondyloarthritis without major safety concerns.