Intervention thresholds for denosumab in the UK using a FRAXA®-based cost-effectiveness analysis

The objective was to undertake a health economic analysis of denosumab for the treatment of osteoporosis in women from the UK, using the FRAXA (R) tool. Denosumab was cost-effective in women with a risk of major osteoporotic fracture meeting or exceeding approximately 20 % who are unable to take, comply with or tolerate generic alendronate. Denosumab is a novel biologic agent developed for the treatment of osteoporosis, which has been shown to reduce the risk of fractures in a phase-III trial. The objective of the present study was to undertake a health economic analysis of denosumab in women from the UK. Ten-year probabilities of a major osteoporotic fracture at which denosumab is a cost-effective alternative to no treatment, generic alendronate, risedronate and strontium ranelate were estimated. A previously published Markov model was adapted to incorporate fracture and mortality risk assessments based on absolute fracture probability, as estimated by FRAXA (R). The model included treatment persistence and residual effect after discontinuation. At a willingness-to-pay (WTP) of A 30,000 pound per quality-adjusted life year and a 10-year fracture probability equivalent to a woman with a prior fragility fracture, denosumab was cost-effective compared to no treatment from the age of 70 years. At the same WTP, denosumab was-irrespective of age-cost-effective compared to no treatment at a major osteoporotic fracture probability of approximately 20 %. Denosumab was estimated to cost-effectively replace strontium, risedronate and generic alendronate at 10-year probabilities exceeding 11, 19 and 32 %, respectively. FRAXA (R) facilitates the estimation of cost-effectiveness-based intervention thresholds applicable to patients with different combinations of clinical risk factors, which more closely matches the situation in clinical practice. Denosumab is cost-effective in patients with major osteoporotic fracture probabilities meeting or exceeding approximately 20 % who are unable to take, comply with or tolerate generic alendronate.