Cost-Effectiveness of Biosimilar Denosumab Versus Bisphosphonates in Postmenopausal Osteoporosis

BACKGROUND/OBJECTIVES: Postmenopausal osteoporosis (PMO) is a major public health and economic burden in the USA. The objective of this study was to evaluate the cost-effectiveness of biosimilar denosumab compared with alendronate, risedronate, ibandronate, and zoledronic acid in treating women with PMO at high risk of fracture from a US payer perspective. METHODS: A cost-effectiveness analysis was conducted using a Markov cohort model and a lifetime horizon was applied to capture long-term costs and effects. Treatment effects were based on published network meta-analyses. The cost of biosimilar denosumab was estimated on the basis of assumptions; other costs were obtained from publicly available sources. Main outcomes included quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs). RESULTS: Biosimilar denosumab was associated with greater efficacy and higher costs versus all comparators. Over a lifetime horizon, the ICER was $101,017, $93,544, $100,515, and $144,995 per QALY gained for biosimilar denosumab compared with alendronate, risedronate, ibandronate, and zoledronic acid, respectively. Cost-effectiveness was most sensitive to starting age, discount rate, treatment duration, and biosimilar price. At a willingness-to-pay (WTP) threshold of $150,000 per QALY gained, biosimilar denosumab was likely to be cost-effective compared with alendronate, risedronate, ibandronate, and zoledronic acid in the treatment of PMO. At a WTP threshold of $100,000 per QALY gained, biosimilar denosumab was likely to be cost-effective relative to risedronate, while ICERs relative to alendronate and ibandronate only marginally exceeded this WTP threshold. CONCLUSIONS: Biosimilar denosumab was estimated to be cost-effective compared with alendronate, risedronate, ibandronate, and zoledronic acid at a WTP threshold of $150,000/QALY gained and compared with risedronate at a threshold of $100,000/QALY gained. As a lower-cost alternative to reference denosumab, biosimilar denosumab may enhance patient access to effective PMO treatment in the USA.