The Non-medical Switch from Reference Adalimumab to Biosimilar Adalimumab is Highly Successful in a Large Cohort of Patients with Stable Inflammatory Rheumatic Joint Diseases: A Real-Life Observational Study

Introduction The adalimumab biosimilar (ADAbio) Amgevita (R) has a similar efficacy and safety profile as the adalimumab reference (ADA) Humira (R). We studied the clinical consequences of a non-medical switch from ADA to ADAbio in adult patients with mainly established rheumatoid arthritis (RA), psoriatic arthritis (PsA), and spondyloarthritis (SpA). Methods Patients that received treatment with ADA for at least three months were switched to ADAbio. Data was collected retrospectively from 1 year before the switch up to 6 months after. Results A total of 603 patients were switched from ADA to ADAbio (switch group). During a 1-year follow-up, over 93% of all patients underwent a successful transition in terms of disease activity and safety from ADA to biosimilar, supporting the bioequivalence of both drugs in patients with stable inflammatory rheumatic joint diseases. Forty patients (6.6%) switched back to ADA (re-switch group). There were no objective changes in disease activity score in 28 joints using C-reactive protein (DAS28-CRP), or adverse effects before and after the switch between both groups. Conclusions In line with earlier reports, the transition to ADAbio went successful in the majority of patients with stable inflammatory rheumatic joint diseases. Patient-reported symptoms without objective signs that indicate a flare of disease activity after the switch to ADAbio are probably explained by nocebo effects. A pre-emptive approach to counteract nocebo effects and stimulate placebo response may have a positive impact on health outcomes for patients and preserve the economic benefits of cost savings that can be achieved by prescribing a biosimilar instead of the reference drug.