First-line fulvestrant plus anastrozole for hormone-receptor-positive metastatic breast cancer in postmenopausal women: a cost-effectiveness analysis

Purpose In a recent randomized, open-label trial (S0226), the addition of fulvestrant to anastrozole therapy decreased the risk of progression and death in patients with hormone-receptor-positive metastatic breast cancer. However, the cost-effectiveness of incorporating fulvestrant into the first-line setting is unknown. Methods We developed a Markov model to assess the costs and clinical outcomes of fulvestrant plus anastrozole compared with anastrozole as a first-line therapy in a cohort of patients with advanced hormone-receptor-positive breast cancer. The transition probabilities were estimated from the fitted survival curves in the S0226 trial. Health care costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) were calculated for fulvestrant plus anastrozole compared with anastrozole from US payer’s perspective. Results Fulvestrant plus anastrozole led to an improvement of 0.11 QALYs compared with treatment with anastrozole alone. However, incorporating fulvestrant into the first-line therapy produced significantly higher health care costs ($72,496 vs. $38,959 for all eligible patients, and $73,728 vs. $37,239 for patients with no previous hormonal adjuvant therapy), resulting in ICERs of $300,564 and $194,450/QALY, respectively. Two-way sensitivity analysis showed that when the cost of fulvestrant decreased to $1.5/mg for all eligible patients or $3.5/mg for patients with no previous hormonal adjuvant therapy, at the perfect health in progression-free status, the ICER became $141,320 and $145,543 per QALY. Conclusion Substituting fulvestrant as a first-line therapy for hormone-receptor-positive metastatic breast cancer is not cost-effective compared with anastrozole based on the willing-to-pay threshold of $150,000 per QALY.