Comparison of costs of different biologic therapies after dose optimization

Abstract

Background: In Croatia, in the treatment of IBD, anti-tumour necrosis factor alpha (anti-TNF) agents infliximab, adalimumab and golimumab, and anti-integrin antibody vedolizumab are available. In patients achieving remission with anti-TNFs, loss of response should be treated firstly by dose optimisation (dose increase or interval shortening). Our aim was to compare costs of different biologic therapies considering the costs of dose optimisation. Method(s): During March of 2017, we collected data of 91 patients with Crohn's disease and ulcerative colitis currently receiving biologic therapy at the Department of Gastroenterology and Hepatology of Clinical Hospital Centre Osijek, Croatia. Data of our interest were: diagnosis, drug used, date of first and last drug application, projected date of next application, drug dosage of last application, and data of whether patient is receiving induction or maintenance therapy. We calculated the projected yearly cost of maintenance therapy with each biologic drug including costs of dose optimisation. Projected yearly costs of maintenance therapy with different biologics were then compared. Drug prices were obtained from currently active list of medications of Croatian Health Insurance Fund. Result(s): 19% of our patients on infliximab and 26% of our patients on adalimumab had dose optimisation due to loss of response. Projected average yearly dose per patient for infliximab considering dose optimisation is 3053 mg/y compared with yearly dose recommended in summary of product characteristics (SmPC), which is 2600 mg/y. For adalimumab, projected average yearly dose per patient considering dose optimisation is 1337 mg/y compared with 1040 mg/y recommended in SmPC. Projected cost of maintenance therapy per year after dose optimisation is 1.2 times higher (12824 vs. 10920 EUR) for infliximab and 1.3 times higher (16055 vs. 12487 EUR) for adalimumab when comparing to costs of maintenance therapy in doses recommended in SmPC. Results are presented in Table 1. Conclusion(s): As our results show, costs of maintenance therapy for certain biologics are higher when considering dose optimisation. Costs of dose optimisation should be considered in pharmacoeconomic analysis of different biologic therapies in inflammatory bowel disease.