Cost-effectiveness of denosumab (Dmab) versus zoledronic acid (ZA) for prevention of skeletal-related events (SREs) in patients (pts) with castrate-resistant prostate cancer (CRPC) and bone metastases (BM).

Abstract

59 Background: It has become more important to understand the incremental cost/benefit of new medicines as healthcare costs rise. Subcutaneous Dmab is superior to intravenous ZA for prevention of SREs in pts with CRPC and BM (Fizazi, 2011). In addition, a lower proportion of pts receiving Dmab progressed to moderate/severe pain than those receiving ZA (Brown, 2011). Dmab can be used in pts regardless of renal status or concomitant use of nephrotoxic drugs. These analyses assess the lifetime, real world cost-effectiveness of Dmab vs ZA in pts with CRPC and BM from a US managed care perspective. Methods: A lifetime Markov model was developed to estimate SREs, quality adjusted life-years (QALYs), and costs. The relative rate reduction in SREs for Dmab vs ZA was based on a large head-to-head phase 3 trial (N=1,901). The real world SRE rate in ZA pts was derived from a large commercial claims database analysis (Hatoum, 2008). SRE QALY decrements were estimated using the time trade-off method (Matza, 2011). SRE costs were estimated from a nationally representative commercial claims database (Barlev, 2010). Wholesale acquisition drug cost (Analysource, 2011), drug administration, and renal monitoring costs (National Fee Analyzer, 2011) were included. Compliance and mortality were assumed to be the same in both groups. Costs and QALYs were discounted at 3% annually. Results: With a median pt survival of 1.7 years, Dmab reduced the number of SREs and increased pts’ QALY vs ZA. The lifetime cost/pt on Dmab was $7,430 higher than ZA. Cost/QALY gained was $65,134, commonly considered good value based on oncologists’ implied threshold in the US (Nadler, 2006). Cost/SRE avoided was $9,212. Conclusions: Dmab is cost-effective in preventing SREs in pts with CRPC and BM compared with ZA in the US. The overall value of Dmab is based on superior efficacy and more efficient administration. [Table: see text]