PCN138 HEALTHCARE RESOURCE UTILIZATION AND TOTAL DIRECT COSTS OF CARE AMONG PATIENTS WITH WALDENSTRÖM MACROGLOBULINEMIA (WM) INITIATING IBRUTINIB IN FIRST LINE VS LATER LINES

Abstract

Ibrutinib is an all-oral, once-daily regimen approved in the US for WM patients across all lines of treatment. Real-world evidence quantifying the benefits of initiating ibrutinib early in patients’ treatment journeys is lacking. This study compared healthcare-resource-utilization (HRU) and total-direct-costs-of-care (TDC; pharmacy+medical) in adults initiating ibrutinib as first-line (1L) vs later-line (2L+) treatment for WM. This retrospective study evaluated ibrutinib patients from the HealthCore Integrated Research Database between 12/01/2013 and 02/28/2019; index date was first claim of ibrutinib. Adults diagnosed with WM with ≥12-month prior (baseline) and ≥1-month post-index continuous enrollment (CE) were included. Patients were followed until earliest of treatment change, discontinuation, CE, or study end date (03/31/2019). Cohort assignments were based on baseline WM treatment. Inverse-probability-of-treatment-weighing (IPTW) was used to account for differences in baseline characteristics. IPTW-adjusted all-cause and WM-related HRU, and TDC mean differences were reported on a per-patient-per-month (PPPM) basis. Among 140 eligible patients, 87 and 53 started ibrutinib as 1L and 2L+ treatment with mean 636 and 714 days of CE follow-up, respectively. Patient characteristics were balanced between 1L (n=138) and 2L+ (n=141) after IPTW-adjustment. Adjusted all-cause HRU findings indicated that 1L patients used significantly fewer outpatient services compared to 2L+ patients (1.1; P<0.001). 1L patients also incurred significantly lower TDC than 2L+ patients ($2,307; P=0.042). This was largely driven by lower medical costs ($1,928; P=0.005) from fewer inpatient ($975; P=0.049), ER ($96; P<0.001), physician ($52; P=0.026), and other outpatient services ($804; P=0.045) costs. WM-related HRU and cost were directionally consistent with all-cause outcomes. Ibrutinib use among WM 1L patients was associated with significantly lower outpatient service use and TDC compared with patients who used ibrutinib in later lines. These data support the value of reduced health-system burden and economic benefits of using ibrutinib early in patients’ treatment journeys.