A Cost-Effectiveness Analysis of Abemaciclib in Combination with Adjuvant Endocrine Therapy for HR+, HER2-,...

The monarchE trial demonstrated that the addition of 2 years of abemaciclib to adjuvant endocrine therapy (ET) significantly reduced the risk of disease recurrence in patients with hormone receptor positive (HR+), and human epidermal growth factor receptor 2-negative (HER2-), node-positive early breast cancer (EBC) at high risk of disease recurrence. Abemaciclib meets a critical unmet need for more effective adjuvant therapy for this patient population. This study evaluates the cost-effectiveness (CE) of abemaciclib plus ET compared to ET alone.

A five-state cohort transition model, which presents a United Kingdom (UK) perspective, is parameterized using data from the monarchE trial and literature. Cost-effectiveness results are presented in terms of cost/quality-adjusted life year (QALY) over a lifetime time horizon. Various assumptions were tested through sensitivity and scenario analyses and uncertainty was assessed through probabilistic analysis.

Patients receiving abemaciclib plus ET were predicted to experience higher QALYs (11.16 compared to 10.42) at an increased cost (£87,541 compared to £48,625), leading to an incremental cost-effectiveness ratio (ICER) of £52,317 per QALY gain compared to ET alone. The increased costs associated with the addition of abemaciclib were partially offset by a reduction in distant disease recurrence and associated costs. The scenario and sensitivity analyses supported robust base case results.

Despite the ICER exceeding usual willingness-to-pay (WTP) levels in the UK, a consequence of using list prices, the CE model utilizing the latest data cut from the monarchE trial, demonstrated that the upfront cost of abemaciclib reduces the risk of a terminal breast cancer prognosis and its associated cost and quality of life impact. The addition of 2 years of abemaciclib provides an option for the treatment of HR+, HER2-, node-positive, high-risk EBC.