Inflammatory bowel disease [IBD] entails a high economic burden to society. We aimed to estimate the current and future impact of the introduction of biosimilars for infliximab on IBD-related health care costs.
We designed a stochastic economic model to simulate the introduction of biosimilars in IBD, using a 5-year time horizon, based on the Dutch situation. Prevalence data on ulcerative colitis [UC] and Crohn's disease [CD] and IBD-related health care costs data were used as input. Assumptions were made on price reductions of anti-tumour necrosis factor [TNF] therapy, increase of anti-TNF prescription rate, and development of hospitalization costs. The base case scenario included a gradual decrease in prices of biosimilars up to 60%, a gradual decrease in prices of original anti-TNF compounds up to 50%, and an annual increase of anti-TNF prescription rate of 1%, and this was compared with no introduction of biosimilars. Sensitivity analyses were performed.
For the base case, cost savings over the total of 5 years were on average €9,850 per CD patient and €2,250 per UC patient, yielding in €493 million total cost savings [a reduction of 28%] for The Netherlands. Results were predominantly determined by price reduction of anti-TNF therapy, threshold price reduction at which physicians switch patients towards biosimilars and the extent to which switching will take place.
The introduction of biosimilars for infliximab can be expected to have a major impact on the cost profile of IBD. The economic impact will depend on local pricing, procurement policies and the physician's willingness to switch patients to biosimilars.