Cost-effectiveness of zoledronic acid and strontium-89 as bone protecting treatments in addition to chemotherapy in patients with metastatic castrate-refractory prostate cancer. (ISRCTN 12808747) TRAPEZE.

e16108 Background: Bony metastatic CRPC has a poor prognosis and high morbidity. TRAPEZE is a factorial RCT using 3 agents, docetaxel (D), zoledronic acid (ZA) and strontium-89 (Sr89). All have palliative benefits and are used in bony metastatic CRPC to control bone symptoms. This study aims to assess the cost-effectiveness of adding bone-protecting treatments—zoledronic acid (ZA) and strontium-89 (Sr89)—to docetaxel chemotherapy for patients with castrate-refractory prostate cancer (CRPC). Methods: Data on resource use and health outcomes collected prospectively in the TRAPEZE 2x2 factorial trial were used to compare the cost-effectiveness of ZA vs. no ZA, and Sr89 vs. no Sr89. Costs are estimated from the NHS perspective. Outcomes are expressed as quality-adjusted life-years (QALYs) and cost-effectiveness is presented as incremental cost per additional QALY. Results: Based on the availability of generic zoledronic acid, the per-patient cost for ZA was £12,667, £251 (95% CIs: -£1,099 to £1,602) higher th...