OBJECTIVES: Non-medical switching (NMS) of biosimilars in hospitals may result in treatment discontinuation or increased health resource utilization (HRU). This retrospective cohort study aims to assess the impact of the introduction of CT-P13 on the healthcare expenditures of patients who were treated with originator infliximab (OI) or CT-P13.

METHODS: Gastroenterology, immunoallergology (IMM) and rheumatology (RHE) patients treated between September 2017 and December 2020 at a university hospital in Western Switzerland were included and divided into seven cohorts, based on their treatment pathway (i.e., use and discontinuation of CT-P13 and/or OI). Costs in Swiss francs (CHF) were obtained from the hospital's cost accounting department and length of stay (LOS) was extracted from inpatient records. Comparisons of costs and LOS between cohorts were calculated by bootstrapping.

RESULTS: Sixty IMM, 84 RHE and 114 GAS patients were included. Inpatient and outpatient costs averaged (sd) CHF 1,611 (1,020) per hospital day (HD) and CHF 4,991 (6,931) per infusion, respectively. The mean (sd) LOS was 20 (28) days. Average costs of IMM and RHE patients were higher than those of GAS patients, however, differences in costs and LOS between cohorts could not be explained by the NMS between OI and CT-P13. Differences in HRU were marginal.

CONCLUSIONS: The introduction of CT-P13 and the disruption of patients' treatment management were not associated with differences in average outpatient and inpatient costs and LOS, in contrast to the results reported in the the literature. Future research should focus on the cost-effectiveness of NMS policies and the potential benefits for patients.