OBJECTIVES: To assess the comparative costs and outcomes with and without the use of difelikefalin for haemodialysis patients with CKD-associated pruritus (CKD-aP).

METHODS: Utilising a Markov model, a cost-utility analysis was performed to assess the incremental cost per QALY gained of CKD-aP treatment which included difelikefalin with best supportive care compared to best supportive care alone in Australia. Health states (severe, moderate, mild and no CKD-aP) of the Markov model were defined based on the Total 5-D Itch Scale score and treatment received. Pooled individual patient data from the double-blind 12-week KALM-1 and KALM-2 studies, along with their 52-week Open Label Extension (OLE) periods were used to derive transition probabilities between 5-D Itch health states over time. The OLE study and assumptions around treatment waning were used to extrapolate health state membership beyond the trial duration to a 10-year model horizon. Implementation of a stopping rule was modelled at week 12, limiting continued difelikefalin treatment to patients with a ≥5-point improvement from baseline in total 5-D Itch score. Utility values were derived from a mapping study between 5-D Itch total scores and EQ-5D-3L. Costs were calculated from the perspective of the Australian healthcare system, with health state costs based on rates of hospitalisation defined by severity of itch.

RESULTS: The difelikefalin with best supportive care treatment arm had greater QALYs than the best supportive care only treatment arm (2.95 vs 2.78) but was more costly (A$19,112 vs A$10,161). The incremental cost per QALY gained of difelikefalin compared to best supportive care was A$51,312 which is considered within an acceptable range in Australia.

CONCLUSIONS: Difelikefalin for treatment of CKD-aP in haemodialysis patients is an effective and cost-effective intervention relative to current practice in Australia.