Treatment of Inflammatory Bowel Disease with Biologics in Japan: A Single-Center, Retrospective Pharmacoeconomic Study

Biologics are essential for treating inflammatory bowel disease (IBD); however, only a few studies have validated cost-effective treatment options and patient factors for biologic use using real-world data from Japanese patients with IBD. Here, we aimed to provide pharmacoeconomic evidence to support clinical decisions for IBD treatment using biologics. We assessed 183 cases (127 patients) of IBD treated with biologics between November 2004 and September 2021. Data on patient background, treatment other than biologics, treatmentrelated medical costs, and effectiveness index (ratio of the C-reactive protein-negative period to drug survival time) were analyzed using univariate and multivariate logistic regression analyses. Drug survival was determined using Kaplan-Meier survival curve analysis. The outcomes were to validate a novel assessment index and elucidate the following aspects using this index: the effectiveness-cost relationship of long-term biologic use in IBD and cost-effectiveness-associated patient factors. Body mass index >= 25 kg/m2 and duration of hypoalbuminemia during drug survival correlated significantly with the therapeutic effectiveness of biologics. There were no significant differences in surgical, granulocyte apheresis, or adverse-event costs per drug survival time. Biologic costs were significantly higher in the group showing lower effectiveness than in the group showing higher effectiveness. These findings hold major pharmacoeconomic implications for not only improving therapeutic outcomes through the amelioration of low albumin levels and obesity but also potentially reducing healthcare expenditure related to the use of biotherapeutics. To our knowledge, this is the first pharmacoeconomic study based on real-world data from Japanese patients with IBD receiving longterm biologic therapy.