Economic Evaluation of Fulvestrant 500 mg Compared to Generic Aromatase Inhibitors in Patients with Advanced Breast Cancer in Sweden

Abstract

Objectives: In Sweden, breast cancer (BC) represents 30% of newly diagnosed cancers and is the most common cancer in women. For hormone-dependent BC, endocrine therapies varying in efficacy and price are available. The aim of this study is to assess the cost effectiveness of fulvestrant 500 mg as a second-line hormonal therapy for postmenopausal women with estrogen receptor-positive metastatic or locally advanced BC versus letrozole, anastrozole, and exemestane in Sweden. Methods: A three-state (pre-progression, post-progression, and death) partitioned-survival model was used to estimate progression-free (PFS) and overall survival (OS) by extrapolating trial results beyond the trial period to capture costs and benefits over a lifetime perspective. The comparative effectiveness was sourced from a network meta-analysis. The evaluation was conducted from a Swedish national payer perspective; costs, resource use, and quality of life were based on published sources and expert opinion. Results: Compared to anastrozole, letrozole, and exemestane the incremental cost-effectiveness ratios (ICERs) were €33,808, €33,883, and €49,225 per QALY with incremental costs of €13,283, €14,986, and €13,862, and incremental QALYs of 0.393, 0.442, and 0.282, respectively. Incremental cost per life-year (LY) gained €21,312 (incremental LY of 0.623), €20,338 (incremental LY of 0.737), and €27,854 (incremental LY of 0.498) for respective comparators. Applying the upper and lower credible intervals for PFS/OS from the meta-analysis had the greatest effect on the ICER in the sensitivity analysis. The results were relatively stable when varying other parameters. Conclusions: Our results indicate that fulvestrant 500 mg may be a cost-effective alternative to aromatase inhibitors at a threshold of €100,000/QALY.