Impact of biosimilars on the costs of advanced therapies for inflammatory bowel diseases: a population-based study in Italy

OBJECTIVE: The use of advanced therapies (biologics and small molecules) for treating inflammatory bowel diseases (IBD) has increased in recent years. We aimed to evaluate the incidence and prevalence of IBD in an Italian province (Barletta-Andria-Trani), the rate of IBD patients treated with advanced therapies, and their costs. METHODS: Case searching used predefined read codes to systematically search computer diagnostic and prescription records from 1 January 2018 to 31 December 2023. All the cases of ulcerative colitis and Crohn's disease were extracted from the electronic database of the Local Health Agency 'Barletta-Andria-Trani'. The same database was queried to assess the rate of IBD patients treated with advanced therapies. RESULTS: During the observational period, the prevalence of Crohn's disease and ulcerative colitis increased significantly from 146.6/100 000 to 203.6/100 000 [95% confidence interval (CI): 0.09-0.11] and from 303.2/100 000 to 408.3/100 000 (95% CI: 0.05-0.06), respectively. The incidence of Crohn's disease and ulcerative colitis showed no statistically significant increase: from 8.3/100 000 to 10.5/100 000 (95% CI: -0.6 to 1.44) and from 13.7/100 000 to 17.6/100 000 (95% CI: -0.12 to 1.6), respectively. The rate of IBD patients treated with advanced therapies increased from 11.9 to 19.3%. Opposite, the costs for advanced therapies decreased from € 1 481 558.19 to 1 171 132.50 (-20.95%). CONCLUSION: This population-based study found increased advanced therapies use partially because of the higher IBD prevalence observed during the study period, but with decreasing costs, mainly attributable to the significant use of anti-tumor necrosis factor αlpha biosimilars.