PSY103 - MODELLING AVERAGE COST AND COST-PER-RESPONDER FOR BIOLOGICAL TREATMENTS FOR MODERATE-TO-SEVERE PLAQUE PSORIASIS WITH DOSE ESCALATION AND REAL-WORLD DRUG SURVIVAL

Abstract

The cost of biological treatment of moderate-to-severe plaque psoriasis in real life depends not only on price and dosing schedule, but also on dose escalation and drug survival. A number of real-world studies have shown dose escalation with etanercept (ETA), infliximab (INF) and ustekinumab (UST) as well as high levels of discontinuation with secukinumab (SEC), INF and ETA. The aim of this study was to model the impact of dose escalation and drug survival on average cost and cost-per-responder. Drug survival and cost of treatment was modelled over 5 years in periods of 4 weeks using discontinuation rates estimated from a literature review. Discontinuation rates were assumed to be linear over time. Costs included drug costs based on labelled dosing or pivotal trials at public selling prices in Sweden. Dose escalation was modelled using a dose multiplier from week 13 for ETA and INF and week 25 for UST, reflecting average dose escalation found in real life. Average costs per 4-week treatment were calculated as total costs divided by total number of treatment periods. Costs from year 2 to 5 were discounted using an annual 3% discount rate. Average cost per PASI100 responder was calculated based on response rates at week 12 or 16 from a Network Meta-Analysis. Sensitivity analyses was conducted for dose multipliers and discontinuation rates. The average cost-per-responder varied between 27.000 SEK for brodalumab (BRO) and ixekizumab (IXE) and 94.000 SEK for UST. Costs-per-responder were sensitive to dose multiplier and less sensitive to drug survival. Costs per responder were more predictable for BRO and ADA than other biologics. Dose escalation and shorter drug survival have high impact on average cost and cost-per-responder. Low induction costs result in more predictable average costs and costs-per-responder. More real world evidence is needed for modern biologics.