Denosumab for elderly men with osteoporosis: A cost-effectiveness analysis from the us payer perspective

Purpose: To evaluate cost-effectiveness of denosumab (Dmab) versus other osteoporotic treatments (txt) in male osteoporosis (MOP) patients ≥75 years (yrs) from a US 3rd party payer perspective. Methods: A lifetime cohort Markov model previously developed for post-menopausal osteoporosis (PMO) was used for the study. During each 6-month cycle, patients could experience a hip, vertebral or other osteoporotic fracture (fx), remain in a non-fx state, remain in a post fx state or die (Figure 1). Background fx risks, mortality rates, persistence rates, health utilities, medical and drug costs were derived from published sources. Bone mineral density (BMD) improvements have shown to be similar between MOP and PMO populations. A recent fx trial showed zoledronate (Zol) to have effects in men similar to those reported previously in women; therefore fx efficacy data from PMO were used. Lifetime expected costs and quality-adjusted life-yrs (QALYs) were estimated for Dmab, generic alendronate (Alen), risedronate, ibandronate, teriparatide, and Zol. Rates of non-persistence for oral and injectable drugs were taken from published reports. Patients in the model were 78 yrs-old, with BMD T-score≤-2.12 and prevalent vertebral fx of 23%, based on the ≥75 yr-old sub-group population in the ADAMO trial comparing 1 yr of Dmab vs. placebo. In the base-case, model assumed patients received txt effects up to 2 yrs after discontinuing (offset time). Costs and QALYs were discounted 3% annually. One-way and probabilistic sensitivity analyses were conducted. Results: Total lifetime costs and QALYs for all txts are shown in Table 1. Dmab had an incremental cost-effectiveness ratio (ICER) of $16,888 compared to Alen and dominated all other txts. Results were most sensitive to changes in drug costs of Dmab and relative risks of hip fx. The probability of Dmab being cost-effective compared to other txts was 75% at a threshold of $50K/QALY and 88% at a threshold of $100K/QALY. In a sensitivity analysis using offset time of 5 yrs for all txts except Dmab (2 yrs) and teriparatide (2.5 yrs), Dmab had an ICER of $21,963 compared to Alen and dominated all other txts. Anticipating the availability of generic Zol, when the price was reduced by 35% and 65% of the brand price (to $705 and $379 annually, respectively), Dmab remained dominant compared to Zol. Conclusion: Dmab is cost-effective compared to other osteoporotic txts in the US elderly male osteoporosis population.