P633 Choice of first biologic in moderate to severe ulcerative colitis – a decision analysis using time-on-treatment and UK costs

Abstract

Abstract Background Vedolizumab and anti-TNFα drugs are biologics that are used to treat moderate to severe ulcerative colitis (UC). In the UK, the decision of which drug to use at first-line is often based on a combination of clinical factors and the price of the drug (based on the one-year cost analysis from the NICE appraisal). The cost of the treatment pathway is rarely considered. Therefore, we investigated whether the choice of first-line biologic affects time-on-treatment and the overall treatment pathway costs by creating a cost model for vedolizumab followed by an anti-TNFα (VDZ–anti-TNFα) compared to anti-TNFα followed by vedolizumab (anti-TNFα–VDZ). Methods A targeted literature search identified 19 studies reporting time-on-treatment data for vedolizumab or anti-TNFαs in UC. We pooled data into four categories: 1) vedolizumab in people who were biologic-naïve (VDZ-1L), 2) anti-TNFα in people who were biologic-naïve (anti-TNFα-1L), 3) vedolizumab after first-line anti-TNFα (VDZ-2L) and 4) anti-TNFα after first-line vedolizumab (anti-TNFα-2L). We then fitted parametric curves to inform time-on-treatment estimates for each category. We calculated ‘direct’ treatment costs by considering drug acquisition, drug administration, dose escalation, concomitant use of immunomodulators and drug monitoring; all costs were sourced from four NHS hospital trusts (cost year 2022). As the duration of the anti-TNFα–VDZ pathway was shorter in duration than VDZ–anti-TNFα (62- vs 44-months), we modelled third line options in the shorter pathway using a weighted basket approach. Third line options included colectomy, tofacitinib, ustekinumab or dose escalation of second-line biologic. Results Over the 62-month time horizon (duration of the longer VDZ–anti-TNFα pathway), pathway costs per patient were similar: £41,439 for VDZ–anti-TNFα and £48,027 for anti-TNFα–VDZ (or £8,021 per year and £9,295 per year, respectively). The model predicted that using vedolizumab first-line delayed the time to costly third-line therapies compared to first-line anti-TNFα. This delay resulted from the pooled time-on-treatment data: VDZ-1L median time-on-treatment 43-months (n=585 people) and anti-TNFα-2L 19-months (n=47); anti-TNFα-1L 17-months (n=7690) and VDZ-2L 27-months (n=549). Conclusion When viewed over a longer period and considering all associated direct costs, a biologic treatment pathway that begins with first-line vedolizumab is not more expensive than one beginning with first-line anti-TNFα in treating moderate to severe UC in the UK. The model shows that considering the longer-term costs of a treatment pathway can give a different result compared to considering the short-term costs of single therapies alone.