OBJECTIVES: To provide an overview of the available real-world data about the use of biosimilar and originator drugs in Lombardy Region, for the treatment of rheumatological, dermatological and gastroenterological diseases, also defining the economic savings generated in case of higher biosimilars’ utilization.

METHODS: An observational study, based on Pharmacy Departments databases, was conducted in 6 hospitals. Data about the typology of administered drugs, number of drugs prescribed, diagnosis and related treatment costs were collected, considering treatment-naïve patients, affected by rheumatological, dermatological or gastroenterological diseases, who received an originator or a biosimilar in 2018-2019, assuming a 24-month follow-up. The potential economic savings generated from switching between originator and biosimilar drugs of the same class (focusing on Anti-TNFα), was defined.

RESULTS: The sample was composed of 1,885 patients, 51% of whom affected by dermatological disease. Most patients were treated with an originator (85%) and for 24 months (61%).Biosimilars are mainly used in the gastroenterological setting (51%), whereas a lower utilization rate emerged in both the dermatological (6%) and the rheumatological area (20%). Considering the drugs’ acquisition hospital costs, patients treated with biosimilars require lower economic resources, for all the settings investigated, with a saving per patient, ranging from 71% to 89%. If a therapeutical switch would have been applied from the originators to their biosimilars (considering adalimumab, etanercept, infliximab and rituximab therapeutical principles), hospitals would benefit from economic savings equal to -47% for the rheumatological setting, -58% for the dermatological one and -34% for gastroenterological patients.

CONCLUSIONS: Despite biosimilars represent both a clinical and a financial opportunity, a low biosimilar penetration could suggest area of resources efficiency in particular concerning the possibility to apply a switch within different therapeutical class. However, if their use would become greater, significant economic hospitals’ savings emerged, with a disease-specific treatment costs optimization.