FALCON Trial: Fulvestrant vs Anastrozole in Hormone Receptor–Positive Advanced Breast Cancer

By: Julia Fiederlein Cipriano, MS
Posted: Friday, November 17, 2023

The primary analysis of the international phase III FALCON trial revealed significantly improved progression-free survival for endocrine therapy–naive, postmenopausal patients with hormone receptor–positive, HER2-negative locally advanced or metastatic breast cancer who received first-line treatment with the estrogen receptor antagonist fulvestrant vs the aromatase inhibitor anastrozole, according to John Robertson, MD, of the University of Nottingham, United Kingdom, and colleagues. They presented the results of the prespecified final overall survival analysis during the European Society for Medical Oncology (ESMO) Congress 2023 (Abstract 384MO).

“No significant difference in overall survival was seen between fulvestrant and anastrozole,” the investigators commented. “The positive trend observed in overall survival for fulvestrant in nonvisceral disease compared with visceral disease is consistent with the primary analysis.”

A total of 462 patients were randomly assigned in a 1:1 ratio to receive either 500 mg of fulvestrant on days 0, 14, and 28, and then monthly thereafter, or 1 mg of anastrozole daily. In the overall population, the median duration of overall survival was 44.8 months with fulvestrant and 42.7 months with anastrozole (hazard ratio [HR] = 0.97, 95% confidence interval [CI] = 0.77–1.21; P = .7579); consistent findings were documented across the prespecified subgroups.

Patients with nonvisceral disease who were treated with fulvestrant vs anastrozole experienced a 15% reduction in the risk of death (median overall survival, 65.2 vs 47.8 months; HR = 0.85); however, the data did not demonstrate statistical significance. The median durations of overall survival were 37.2 and 40.7 months, respectively, in those with visceral disease (HR = 1.06, 95% CI = 0.80–1.42).

The investigators reported no meaningful differences in quality of life between the treatment arms. No new safety signals were identified.

Disclosure: For full disclosures of the study authors, visit cslide.ctimeetingtech.com.

ESMO Congress 2023