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

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