Cost-effectiveness intervention thresholds for romosozumab and teriparatide in the treatment of osteoporosis in the UK

Sequential romosozumab-to-alendronate or sequential teriparatide-to-alendronate can be a cost-effective treatment option for postmenopausal women at very high risk of fracture.

To estimate the 10-year probability of a major osteoporotic fracture (MOF) at which sequential treatment with romosozumab or teriparatide followed by alendronate, compared with alendronate alone, becomes cost-effective in a UK setting.

A microsimulation model with a Markov structure was used to simulate fractures, costs, and quality-adjusted life years (QALYs), in women receiving sequential treatment with either romosozumab or teriparatide followed by alendronate, compared with alendronate alone. Patients aged 50 to 90 years with a recent MOF, hip or spine fracture were followed from the start of a 5-year treatment until the age of 100 years or death. The analysis had a healthcare perspective. Efficacy of romosozumab, teriparatide and alendronate was derived from phase III randomised controlled trials. Resource use and unit costs were derived from the literature. Cost-effectiveness intervention threshold (CEIT), defined as the 10-year probability of a major osteoporotic fracture at which treatment becomes cost-effective, was compared with clinically appropriate intervention thresholds for bone-forming treatment in women with very high fracture risk as recommended by the UK National Osteoporosis Guideline Group (NOGG).

The base case analysis showed that sequential romosozumab-to-alendronate treatment was cost-effective from a 10-year MOF probability of 18–35% and above depending on age and site of sentinel fracture at a willingness to pay (WTP) of £30,000. For teriparatide-to-alendronate, treatment was cost-effective at a 10-year MOF probability of 27–57%. The results were sensitive to pricing of the drugs but relatively insensitive to treatment duration, romosozumab persistence assumptions, and site of sentinel fracture. The CEITs for romosozumab-to-alendronate treatment were lower than the clinical thresholds from the age of 70 years meaning that treatment could be considered both cost-effective and aligned with the NOGG treatment guidelines. By contrast, for teriparatide-to-alendronate the CEITs were higher than the clinical thresholds irrespective of age. However, cost-effective scenarios were found in the presence of strong clinical risk factors in addition to a recent sentinel fracture.

The results of this study indicate that sequential romosozumab-to-alendronate or teriparatide-to-alendronate treatment can be a cost-effective treatment option for postmenopausal women at very high risk of fracture.