Cost-effectiveness analysis of the addition of metastasis directed therapy to intermittent hormone therapy for oligometastatic prostate cancer

Summary: The treatment landscape for patients with oligometastatic disease has recently been transformed by the emergence and adoption of metastasis-directed therapy (MDT) as a novel paradigm. The recently published phase II EXTEND trial demonstrated that combining MDT with intermittent hormone therapy improved progression free survival (PFS) and eugonadal PFS over hormone therapy alone in patients with oligometastatic prostate cancer,1 although this treatment strategy may be associated with significant costs. This current study aims to evaluate the comparative cost-effectiveness of the addition of MDT to intermittent hormone therapy from a US healthcare sector perspective. The EXTEND trial prostate intermittent hormone therapy basket included men with oligometastatic prostate cancer, with 5 or fewer metastases and treated with 2 or more months of hormone therapy prior to enrollment (ClinicalTrials.gov Identifier: NCT03599765). These patients were randomized to receive MDT with intermittent hormone therapy versus hormone therapy alone. We constructed a state-transition microsimulation model to simulate patients randomized to the study treatment arms, according to an intention-to-treat principle. Hormone therapy included luteinizing hormone-releasing hormone agonist or antagonist with or without a second-generation androgen receptor–targeting (SART) agent, with the percent of patients receiving a SART modeled based on patients included in the EXTEND trial. Hazard rates of disease progression and death were based on the individual patient data from primary analysis of the EXTEND trial. Inputs for quality of life utility weights were derived from the literature, and costs were based on Medicare reimbursement rates and literature. We performed probabilistic sensitivity analysis and estimated costs and quality-adjusted life years (QALYs) over a 3-year time horizon. We estimated the net monetary benefit using a willingness-to-pay threshold of $50,000. The addition of MDT to intermittent hormone therapy was the dominant strategy in the base case analysis. Costs were $80,267 (95% uncertainty interval $80,196 to $80,328) vs $93,844 ($93,772 to $93,917) and QALYs were 2.23 (2.23 to 2.24) vs 1.51 (1.51-1.51) for upfront MDT combined with intermittent hormone therapy versus hormone therapy alone, respectively. This reflected a net monetary benefit of $31,142 ($31,226 to $31,598) vs -$18,382 (-$18,572 to -$18,192), respectively. At 3 years, upfront MDT combined with intermittent hormone therapy is a cost-effective strategy compared to hormone therapy alone. Additional analyses are required to evaluate the comparative cost-effectiveness of these treatment approaches from a societal perspective and in the context of varying hormone therapy approaches. Kathryn E. Marqueen, MD (Presenting Author) - University of Texas MD Anderson Cancer Center; Alexander D. Sherry, MD (Co-Author) - University of Texas MD Anderson Cancer Center; Tharakeswara Bathala, MD (Co-Author) - University of Texas MD Anderson Cancer Center; Suyu Liu, PhD (Co-Author) - University of Texas MD Anderson Cancer Center; Bryan Fellman, MS (Co-Author) - University of Texas MD Anderson Cancer Center; Ana Aparicio, MD (Co-Author) - University of Texas MD Anderson Cancer Center; Amado Zurita-Saavedra, MD (Co-Author) - University of Texas MD Anderson Cancer Center; Stephen Chun, MD (Co-Author) - University of Texas MD Anderson Cancer Center; Jay Reddy, MD, PhD (Co-Author) - University of Texas MD Anderson Cancer Center; Amol Ghia, MD (Co-Author) - University of Texas MD Anderson Cancer Center; Sean McGuire, MD, PhD (Co-Author) - University of Texas MD Cancer Center; Jianbo Wang, MD (Co-Author) - University of Texas MD Anderson Cancer Center; Patrick Pilie, MD (Co-Author) - University of Texas MD Anderson Cancer Center; Craig Kovitz, MD (Co-Author) - University of Texas MD Anderson Cancer Center; Samantha Simiele, PhD (Co-Author) - University of Texas MD Anderson Cancer Center; Brian Chapin, MD (Co-Author) - University of Texas MD Anderson Cancer Center; Paul Corn, MD, PhD (Co-Author) - University of Texas MD Anderson Cancer Center; Seungtaek Choi, MD (Co-Author) - University of Texas MD Anderson Cancer Center; Iakovos Toumazis, PhD (Co-Author) - University of Texas MD Anderson Cancer Center; Chad Tang, MD (Co-Author) - University of Texas MD Anderson Cancer Center