Cost effectiveness of difelikefalin compared to standard care for treating chronic kidney disease associated pruritus (CKD-aP) in people with kidney failure receiving haemodialysis

Background: Chronic kidney disease-associated pruritus (CKD-aP) is associated with an increased risk of depression, poor sleep and reduced health-related quality of life. Two phase III studies (KALM-1 and KALM-2) of difelikefalin showed reduced CKD-aP severity and improved itch-related health-related quality of life in patients with moderate and severe CKD-aP receiving haemodialysis for kidney failure. Objective: We aimed to estimate the cost effectiveness of difelikefalin for patients with CKD-aP receiving haemodialysis for kidney failure compared to standard care from a UK National Health Service perspective. Methods: A cohort model was developed with four health states representing levels of pruritus intensity over time, based on the KALM trials augmented with longer term CKD-aP severity data from another haemodialysis trial (SHAREHD) for standard care. Utilities were estimated from a mapping study of 5-D Itch to EQ-5D-5L in 487 patients receiving haemodialysis, costs were estimated based on resource use alongside the SHAREHD and 2018 unit costs, and inflated to 2021 costs. Costs and quality-adjusted life-years were discounted at 3.5% per annum. A de novo economic model was developed in Microsoft Excel with scenario analyses performed using a range of assumptions. Results: In the base-case analysis over a time horizon of 64 weeks, using a placeholder cost of £75 per 28-days for difelikefalin, the incremental cost-effectiveness ratio of difelikefalin compared with standard care was £19,558/quality-adjusted life-year (QALY). Scenario analyses resulted in incremental cost-effectiveness ratios that ranged from £10,154/QALY (severe only) to £16,957/QALY (5-year horizon) for difelikefalin compared to standard care. Probabilistic sensitivity analyses suggested difelikefalin has a 48.6% probability of being cost effective at a threshold of £20,000/QALY and a 57.2% probability of being cost effective at a threshold of £30,000/QALY. Conclusions: The cost effectiveness of difelikefalin in a range of scenarios could make it an important pharmacotherapy to address the high burden of disease and unmet need for treatments associated with CKD-aP in the UK.