A Probabilistic Cost-Effectiveness Analysis of Venetoclax and Obinutuzumab as a First-Line Therapy in Chronic Lymphocytic Leukemia in Canada.

BACKGROUND: Venetoclax is a first-in-class targeted therapy option that is an inducer of apoptosis in chronic lymphocytic leukemia (CLL) cells. The open-label phase III CLL14 clinical trial showed that venetoclax combined with obinutuzumab (VEN+O) is superior to obinutuzumab combined with chlorambucil in newly diagnosed patients with CLL. The aim of this study was to assess the health economic value of VEN+O for the frontline treatment of CLL in Canada from a publicly funded healthcare system perspective.

METHODS: A partitioned survival analyses model was developed including three health states: progression free, progressed, and death. A cycle length of 28 days and a time horizon of 10 years was assumed. VEN+O treatment for a fixed duration of 12 months was compared to obinutuzumab combined with chlorambucil, fludarabine plus cyclophosphamide plus rituximab, bendamustine plus rituximab, chlorambucil plus rituximab, ibrutinib, and acalabrutinib. The population in the model included both unfit and overall frontline CLL patients, two subgroups were also assessed (patients with del17p/TP53 mutations and patients without del17p/TP53 mutations). Survival data extrapolated from the CLL14 trial were used to populate the model. Uncertainty was assessed via one-way sensitivity analyses, probabilistic analyses, and scenario analyses.

RESULTS: Based on the probabilistic analyses, unfit frontline CLL patients receiving VEN+O were estimated to incur costs of Canadian dollars ($) 217,727 [confidence interval (CI) $170,725, $300,761] (del17p/TP53: $209,102 [CI $159,698, $386,190], non-del17p/TP53: $217,732 [CI $171,232, $299,063]) and accrue 4.96 [CI 4.04, 5.82] quality-adjusted life-years (del17p/TP53: 3.11 [CI 2.00, 4.20], non-del17p/TP53: 5.04 [CI 4.05, 5.92]). Obinutuzumab combined with chlorambucil, bendamustine plus rituximab, chlorambucil plus rituximab, and ibrutinib accrued lower quality-adjusted life-years and higher costs and as such, VEN+O was the dominant treatment option. The full incremental analysis showed that acalabrutinib was more expensive and more efficacious compared with VEN+O with an incremental-cost-effectiveness-ratio of $2,139,180/quality-adjusted life-year versus VEN+O and not a cost-effective option in Canada. Probabilistic analyses show that at a willingness to pay of $50,000/quality-adjusted life-year gained, VEN+O has the greatest probability of being cost effective.

CONCLUSIONS: VEN+O is a cost-effective treatment option for unfit frontline CLL patients and provides value for money to healthcare payers.