OBJECTIVES: To evaluate the cost-effectiveness of fulvestrant versus anastrozole as first-line treatment for locally advanced or metastatic breast cancer in postmenopausal women with oestrogen receptor-positive tumours.

METHODS: A partitioned survival model with monthly cycles was developed with three health states including progression-free, progressed disease and death. Progression-free survival and overall survival data were obtained from the FIRST (Robertson et al., 2009; Ellis et al., 2015) and FALCON (Robertson et al., 2016) studies. Parametric survival analysis was conducted to extrapolate the data to a life-time horizon of 15 years. Patients entered the model at age 62 years old, based on the average age from the control arm in the FALCON trial. The economic evaluation was done from a UK NHS perspective. Outcomes of interest were quality adjusted life years (QALYs) and life years gained (LYG). EQ-5D data from Lloyd 2006 were used to determine the utilities in the model. All costs and outcomes were discounted at an annual rate of 3.5%.

RESULTS: Fulvestrant resulted in an additional 0.51 QALYs and one LYG compared to anastrozole. The base case results estimated an incremental cost-effectiveness ratio (ICER) of £59,914.38 per QALY gained, which exceeds the threshold set by NICE. The cost per LYG was £28,824.68. The probabilistic sensitivity analysis (PSA) showed similar results to the base case. The ICER from the PSA was £59,744.40 per QALY and £31,698.74 per LYG. At a threshold of £20,000 and £30,000, the probability of fulvestrant being cost-effective was 5.58% and 10.02%, respectively.

CONCLUSIONS: Fulvestrant is considered more effective than anastrozole, but at a higher cost. Due to the high ICER, fulvestrant is not considered a cost-effective treatment for this population.