A comprehensive evaluation of the transition to a biosimilar of adalimumab in rheumatoid arthritis and psoriatic arthritis: a single-center experience with a focus on imaging outcomes.

Objective: Limited data in Latin America exists regarding the efficacy of switches from original biologicals to biosimilars in real-life scenarios. Currently, no studies assess this switch using imaging. The objective of this study was to evaluate clinical, functional, ultrasonographic, and radiological responses in a group of patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA) switched from original adalimumab (oADA) to biosimilar (bADA) (GP2017).

Methods: A prospective cohort study included diagnosed RA and PsA patients undergoing oADA treatment. At the baseline visit, blood analysis, X-rays, ultrasound, and an interview for sociodemographic and clinical data were conducted. Evaluators were unaware of each other's data. Patients switched to bADA during follow-up and were assessed in the same program within 3 to 12 months post-switch (only including patients with all evaluations).

Results: Out of 270 RA cohort patients, 35 met the criteria for complete pre- and post-control post-switch to bADA (GP2017), along with 15 PsA patients. The mean time between the switch and the second evaluation was 4.1 months (interquartile range 7). No statistical differences were observed in disease activity or functional capacity. Regarding imaging, no difference was found in X-ray erosion number; however, ultrasonography revealed decreased power Doppler (PD) activity, but not grayscale changes. No differences in acute phase reactants, joint count, or patient visual analog scale were observed between controls.

Conclusions: In this analysis of the switch between oADA and bADA, no differences were found in disease activity, functional capacity, or radiographic progression. Ultrasonography indicated improvement of PD findings.