The Economic Impact of the Introduction of Infliximab-Biosimilar: Preliminary Results from a Study on Rheumatologic Patients in Tuscany, Italy

Background: The introduction of biosimilars can be a chance to significantly impact on the sustainability of National Healthcare Systems; however the real economic impact still needs to be clarified. Objectives: To assess the economic impact of the use of biosimilar infliximab (BI) considering rheumatoid arthritis (RA) patients and Tuscany (Italy) as case study, benefiting from the “counterfactual” set in 2015 when the Tuscan Health Authority encouraged physicians to switch patients from originator infliximab (OI) to BI. Methods: We estimated the economic impact of the introduction of BI in Tuscan rheumatoid arthritis (RA) patients from the perspective of the Regional Health System and valuing direct costs related to biologics (infliximab and other treatment), emergency room visits, hospitalizations and specialist visits using data from Tuscan healthcare administrative databases. We performed two analyses on: 1) patients naïve to infliximab from January 1st, 2012 to December 31st, 2016, treated with OI before 2015 and with OI or BI after 2015; 2) prevalent infliximab users from January 1st, 2013 to December 31st, 2013 (before the BI recommendation) and from January 1st, 2015 to December 31st, 2015 (post the BI recommendation). We evaluated costs up to 1 year in the first analysis and up to 2 years in the second one. Results: The mean annual direct costs related to infliximab (OI or BI) among naïve patients (n = 214) decreased from 9,823 ± 5,308 Euro in 2012 to 7,406 ± 4,406 Euro in 2016 (p = 0.025), similarly for the mean overall direct costs related to the disease management that decreased of about 4,000 Euro from the first (13,793 ± 6,222 Euro per patient/year) to the last observation year (9,989 ± 5,729 Euro per patient/year, p = 0.004). We also observed a decrease of both direct costs related to infliximab and overall direct costs by comparing prevalent infliximab RA patients in the pre‐recommendation group (n = 354) to patients in the post recommendation group (n = 334). In particular, mean costs related to infliximab over 2 years were 15,315 ± 9,843 Euro per patient among those treated with OI and 12,383 ± 9,141 Euro per patient among those treated with either OI or BI (p < 0.001); similarly, 2 years mean overall direct costs were 20,622 ± 9,712 Euro per patient and 18,414 ± 9,441 Euro per patient, respectively (p = 0.003). Conclusions: The introduction of BI produced a reduction of direct costs for the management of RA patients. This template analysis can be repeated whenever a new biosimilar drug enters the market. Causal mechanisms underlying the economic impact warrant further analysis.