Background: Teriparatide is a promising new agent for the treatment of osteoporosis.

Methods: The objective of this study was to evaluate the cost-effectiveness of teriparatide-based strategies compared with alendronate sodium for the first-line treatment of high-risk osteoporotic women. We developed a microsimulation with a societal perspective. Key data sources include the Study of Osteoporotic Fractures, the Fracture Intervention Trial, and the Fracture Prevention Trial. We evaluated postmenopausal white women with low bone density and prevalent vertebral fracture. The interventions were usual care (UC) (calcium or vitamin D supplementation) compared with 3 strategies: 5 years of alendronate therapy, 2 years of teriparatide therapy, and 2 years of teriparatide therapy followed by 5 years of alendronate therapy (sequential teriparatide/alendronate). The main outcome measure was cost per quality-adjusted life-year (QALY).

Results: For the base-case analysis, the cost of alendronate treatment was $11 600 per QALY compared with UC. The cost of sequential teriparatide/alendronate therapy was $156 500 per QALY compared with alendronate. Teriparatide treatment alone was more expensive and produced a smaller increase in QALYs than alendronate. For sensitivity analysis, teriparatide alone was less cost-effective than alendronate even if its efficacy lasted 15 years after treatment cessation. Sequential teriparatide/alendronate therapy was less cost-effective than alendronate even if fractures were eliminated during the alendronate phase, although its cost-effectiveness was less than $50 000 per QALY if the price of teriparatide decreased 60%, if used in elderly women with T scores of -4.0 or less, or if 6 months of teriparatide therapy had comparable efficacy to 2 years of treatment.

Conclusions: Alendronate compares favorably to interventions accepted as cost-effective. Therapy with teriparatide alone is more expensive and produces a smaller increase in QALYs than therapy with alendronate. Sequential teriparatide/alendronate therapy appear expensive but could become more cost-effective with reductions in teriparatide price, with restriction to use in exceptionally high-risk women, or if short courses of treatment have comparable efficacy to that observed in clinical trials.