P1-17. The cost-effectiveness of ustekinumab in moderate to severely active Crohn’s disease in Sweden and Norway
Amanda Hansson-Hedblom , Chrissy Almond , Fredrik Borgström , Indeg Sly , Dana Enkusson , Anders Troelsgaard Buchholt , Linda Karlsson 
Affiliates:  Quantify Research, Stockholm, Sweden,  BresMed, Sheffield, United Kingdom,  Janssen-Cilag AB, Solna, Sweden
Novel Crohn’s disease (CD) treatment ustekinumab is a human monoclonal antibody blocking pro-inflammatory cytokines interleukins (IL)-12 and IL-23. We assessed the cost-effectiveness of ustekinumab in moderate-to-severely-active CD in Sweden and Norway.
A cost-effectiveness model was constructed with a decision tree structure for the induction phase and a Markov cohort structure for the maintenance phase. The model contains five health-states: remission, mild, moderate-severe, surgery and death. Ustekinumab was compared to adalimumab in a conventional-care-failure population and to vedolizumab in a TNF-alpha-inhibitor-failure population. Induction efficacy for ustekinumab, utilities and discontinuation probabilities were sourced from phase-III clinical trials. Maintenance and comparator efficacy were based on network-meta-analyses and treatment-sequence-analyses. Unit costs and resource use for the countries were obtained from literature and validated by local clinical experts. The analyses had a societal perspective, a life-time time-horizon, and a 2-year treatment duration. Univariate and probabilistic sensitivity analyses (PSA) were performed to test the robustness of the results. Cost-effectiveness was estimated using quality-adjusted life-years (QALYs).
Ustekinumab dominated adalimumab in the conventional-care-failure population in both countries. The incremental cost-effectiveness ratio (ICER) in the TNF-alpha-inhibitor-failure population versus vedolizumab was €30,282 in Sweden and €9,008 in Norway (Table 1). In both countries, results were sensitive to increasing treatment duration and excluding indirect costs. Increasing treatment duration improved cost-effectiveness versus adalimumab but increased the ICER versus vedolizumab. PSA showed that at respective country’s reference willingness-to-pay (WTP) (SEK 600,000/€63,000 and NOK 600,000/€65,000), probability of cost-effectiveness versus adalimumab was 94% in both countries, and 72% in Sweden and 82% in Norway versus vedolizumab.
Results indicate ustekinumab dominates adalimumab in a conventional-care-failure population, and is cost-effective versus vedolizumab in a TNF-alpha-inhibitor-failure population.