Cost-utility of denosumab for the treatment of postmenopausal osteoporosis in Spain

Abstract

Josep Darbà,1 Lisette Kaskens,2 Francesc Sorio Vilela,3 Mickael Lothgren4 1Department of Economics, Universitat de Barcelona, 2BCN Health Economics and Outcomes Research SL, 3Amgen SA, Barcelona, Spain; 4Amgen (Europe) GmbH, Zug, Switzerland Background: The objective of this study was to estimate the cost-effectiveness of denosumab for fracture prevention compared with no treatment, generic bisphosphonates, and strontium ranelate in a cohort of osteoporotic postmenopausal women in Spain. Methods: A Markov model represented the possible health state transitions of Spanish postmenopausal women from initiation of fracture prevention treatment until age 100 years or death. The perspective was that of the Spanish National Health System. Fracture efficacy data for denosumab were taken from a randomized controlled trial. Fracture efficacy data for alendronate, ibandronate, risedronate, and strontium ranelate were taken from an independent meta-analysis. Data on the incidence of fractures in Spain were either taken from the published literature or derived from Swedish data after applying a correction factor based on the reported incidence from each country. Resource use in each health state was obtained from the literature, or where no data had been published, conservative assumptions were made. Utility values for the various fracture health states were taken from published sources. The primary endpoints of the model were life-years gained, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios for denosumab against the comparators. Results: Denosumab reduced the risk of fractures compared with either no treatment or the other active interventions, and produced the greatest gains in life-years and QALYs. With an annual acquisition cost of €417.34 for denosumab, the incremental cost-effectiveness ratios for denosumab versus no treatment, alendronate, risedronate, and ibandronate were estimated at €6,823, €16,294, €4,895, and €2,205 per QALY gained, respectively. Denosumab dominated strontium ranelate. Sensitivity analyses confirmed the robustness of these findings. Conclusion: Our analyses show that denosumab is a cost-effective intervention for fracture prevention in osteoporotic postmenopausal women in Spain compared with alendronate and risedronate, and is a dominant treatment option compared with strontium ranelate. Keywords: osteoporosis, post-menopausal, cost-utility, denosumab, Spain