Introduction: Pruritus associated with PBC affects sleep and social and emotional wellbeing. Limited data exist on the impact of pruritus on health utility (a value between 0 [death] and 1 [perfect health]), commonly used in health technology assessments to calculate quality-adjusted life years and compare different conditions. A recent UK study explored EQ-5D utilities in a broad PBC population.1 Here, using data from the Phase 2b GLIMMER study (post hoc) investigating linerixibat for the treatment of pruritus in PBC (NCT02966834), the impact of itch severity on health utility in PBC is explored and quantified for the first time.
Methods: Patients in GLIMMER recorded itch twice daily on a 0–10 numeric rating scale (NRS) and completed the EQ-5D-5L at study entry, baseline (BL) and end of treatment. BL followed a 4-week single-blind placebo run-in. Patients were classed as having mild (< 4), moderate (≥4 to < 7) or severe pruritus (≥7 to 10) based on mean Worst Daily Itch NRS score in the 7 days prior to BL.
Results: The GLIMMER population (N=147) was 94% female with a mean (SD) age at BL of 55.8 (11.04) years. Most patients had moderate pruritus (n=76), with similar numbers with mild (n=35) and severe (n=36) pruritus. At BL, alkaline phosphatase levels were higher with greater itch severity: mean (SD) 177 (115.4) and 249 (190.8) IU/L in patients with mild and severe itch, respectively. Overall, mean (SD) BL utility was 0.69 (0.23), lower than the general PBC population (Figure) and with a clear and notable impact of pruritus severity on health utility. Thus, patients with mild or moderate pruritus at BL had similar utilities (0.75 [0.17] and 0.76 [0.17], respectively), marginally lower than the general UK population (mean at age 55–64 years: 0.804). Patients with severe pruritus at BL had notably worse utility (0.49 [0.28]), similar to patients with severe Parkinson’s disease (0.47 [0.22]; Figure). Over the course of the study health utility declined in the placebo group (–0.01) and increased across all linerixibat arms (0.04–0.05). Although improvements were small (confidence intervals crossed zero), the directional change supports a treatment effect of linerixibat.
Discussion: Pruritus (particularly severe pruritus) has a significant negative impact on HRQoL and health utility. Presence and severity of itch should be evaluated in PBC and prioritized in treatment plans.
1. Rice et al. Clin Gastroenterol Hepatol 2021;19:769–76.
