Cost-Effectiveness of Sequential Teriparatide/Alendronate Versus Alendronate-Alone Strategies in High-Risk Osteoporotic Women in the US: Analyzing the Impact of Generic/Biosimilar Teriparatide

Teriparatide, currently only available in brand form in the United States, is a costly drug approved for the treatment of postmenopausal osteoporotic women who are at high risk of fracture. Because market exclusivity for brand teriparatide expired in August 2019 in the US, we sought to understand the potential health economic impact of the availability of generic or biosimilar (generic/biosimilar) teriparatide. We examined the cost-effectiveness of daily teriparatide for 2 years followed by weekly alendronate for 10 years (ie, sequential teriparatide/alendronate) compared with alendronate alone for 10 years in community-dwelling white osteoporotic women with prior vertebral fracture at ages 65, 70, 75, and 80. Using an updated version of previously validated Markov microsimulation models, we obtained incremental cost-effectiveness ratios (ICERs) (dollars [$] per quality-adjusted life year [QALY]) with a willingness-to-pay (WTP) of $150,000 per QALY from a societal perspective with a lifelong time horizon. In the base case, we estimated the annual cost of teriparatide to be $20,161, based on the assumption of 10% brand usage (at a cost of $27,618) and 90% generic/biosimilar usage (priced 30% lower than brand). The ICERs of sequential teriparatide/alendronate compared with alendronate alone were greater than $280,000 per QALY at all ages examined. In deterministic sensitivity analyses, results were sensitive to teriparatide's cost, with the cost of a generic/biosimilar product needing to be 65% to 85% lower than brand for sequential teriparatide/alendronate to be cost-effective. In probabilistic sensitivity analyses, under the assumption that the annual cost of teriparatide was $20,161, the probabilities of sequential teriparatide/alendronate being cost-effective were less than 4% at a WTP of $150,000 per QALY. In conclusion, among community-dwelling older osteoporotic women with prior vertebral fracture in the US, even with the potential availability of generic/biosimilar teriparatide, sequential teriparatide/alendronate would not be cost-effective unless the cost of generic/biosimilar teriparatide were heavily discounted with respect to the current brand cost. (C) 2019 The Authors. JBMR Plus published byWiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.