Value of risk-directed thromboprophylaxis in ambulatory lung and gastrointestinal cancer care: Economic evaluation of the TARGET-TP randomized trial.

12137 Background: Thromboembolism (TE) is a major and preventable hematological complication in patients with cancer, contributing to substantial adverse health impacts for patients and the health system. Targeted Thromboprophylaxis in Ambulatory Patients Receiving Anticancer Therapies (TARGET-TP; ACTRN12618000811202) was an Australian phase III randomized trial of biomarker risk-directed enoxaparin thromboprophylaxis. The TARGET-TP intervention reduced TE (HR 0.31, p = 0.005) and six-month mortality (HR 0.48, p = 0.03) versus usual care (no prophylaxis). This study evaluated the value for money of the TARGET-TP intervention versus usual care. Methods: A within-trial and modelled economic evaluation was conducted from the Australian health system perspective. Resource use collected within the trial reflected risk stratification, thromboprophylaxis, side-effect management, and treatment of TE events. Health benefits were quantified as quality-adjusted life years (QALYs), utilities derived from SF-12v2 data. Bootstrapping was used to evaluate sampling uncertainty. A Markov model estimated long-term costs and outcomes over a 5-year horizon. Scenarios assessed the use of oral anticoagulants and stewardship, while probabilistic sensitivity analysis (PSA) tested parameter uncertainty. Results: Within-trial analysis showed the TARGET-TP intervention was associated with lower costs, while being more effective (i.e., dominant), reducing costs by $1,095 per patient and generating an additional 0.0097 QALYs, driven mainly by fewer hospitalizations. The TARGET-TP intervention was dominant in > 83% of bootstrap iterations. Modelled analyses supported these findings, with cost savings of $3,551 per patient and a gain of 0.4 QALYs. PSA demonstrated dominance in > 95% of iterations (Figure 1). The oral anticoagulant and stewardship scenarios remained dominant for rivaroxaban, while apixaban was highly cost-effective, driven by bleeding events and drug costs. Conclusions: Biomarker-driven primary thromboprophylaxis in patients with lung and gastrointestinal cancer was less costly and more effective from the healthcare system perspective, supporting its implementation in routine care. Clinical trial information: ACTRN12618000811202.