Biosimilars and reference biological medicines in the treatment of rheumatoid arthritis: a multicenter cross-sectional study in Catalonia, Spain.

Abstract

Objective: The objective of this study is to compare the effectiveness of reference biologic medicines used in the treatment of rheumatoid arthritis (RA) specifically adalimumab, etanercept, and infliximab, with corresponding biosimilar medicines, based on an exploratory analysis of clinical data obtained in patients treated with these medicines in five hospitals in the region of Catalonia, Spain.

Methods: There is a consultation of the database of the Registry of Patients and Treatments of the Catalan Health Service: extraction of data from adult patients diagnosed with moderate and severe active RA and with active prescription of at least one biological drug (reference or biosimilar) or JAK inhibitor. To compare the effectiveness of each reference biologic with its biosimilar, differences in mean DAS28-ESR values before and after treatment were assessed for adalimumab and its biosimilar, etanercept and its biosimilar, and infliximab and its biosimilar.

Results: The study consisted of 643 patients. The most dispensed medicines were anti-TNFs, with 303 patients on treatment. Thirty-six percent of all patients were using biosimilars. No statistically significant differences were observed in any of the three comparisons between the reference biologic medicine and its biosimilar. These findings suggest that biosimilars have comparable effectiveness to reference biologics in reducing DAS28-ESR; in addition, they can provide substantial savings to public health systems.

Conclusions: A significant number of patients diagnosed with moderate to severe active RA were treated with biological medicines and receiving the available biosimilar treatments. Future research should be conducted to confirm comparable effectiveness found to their reference biologic medicines in this exploratory analysis. Key Points • Biosimilar use: 36% of rheumatoid arthritis (RA) patients in Catalonia are treated with biosimilars, exceeding the 12% recommendation. This reflects growing acceptance of these alternatives. • Comparative effectiveness: Biosimilars of adalimumab, etanercept, and infliximab showed comparable therapeutic benefit to their reference biologics in reducing disease activity in active rheumatoid arthritis. • Real-world data: The study provides real-world data from five hospitals, making biosimilar medicines a viable choice for rheumatologists in routine rheumatoid arthritis management.