Budget impact analysis of infliximab biosimilar: the Italian scenery

Chronic inflammatory diseases, while seriously impairing patients' quality of life, are a heavy financial cost to the National Health Service (NHS) and to society. The availability of biological drugs - among which infliximab (Remicade (R)) - greatly improved treatment efficacy. On the other hand, these drugs are an expensive resource. Infliximab patent protection is going to expire, and a biosimilar has been recently approved. A budget impact (BI) analysis was conducted to evaluate the favourable consequences - for the Italian NHS - of the biosimilar availability in terms of cost containment (savings), thanks to its lower price compared to the originator's. The analysis model expects that some patients in treatment with the originator will switch (according to a prudent assumption of the market uptake rate) to the biosimilar and that many naive patients will directly start treatment with the biosimilar (according to a bolder uptake rate assumed). Separately considering all the different diseases for which infliximab is indicated, the number of patients who might potentially use the biosimilar is estimated - based on disease prevalence and incidence rates, the overall proportion of treated patients and the infliximab market share. The time horizon extends to five years (starting from 2015). The biosimilar price discount is 25%. The results from the analysis show (in the base case) that the availability of the biosimilar would provide overall annual savings over (sic)16 million to the NHS in 2019, while the cumulated savings in the five years period would be no less than (sic)47 million. The sensitivity analysis highlights that such favourable results would be even more substantial, to the extent that switching from originator to biosimilar could be safely recommended.