LBA14_PR - FALCON: A phase III randomised trial of fulvestrant 500 mg vs. anastrozole for hormone receptor-positive advanced breast cancer

Date 08 October 2016
Event ESMO 2016 Congress
Session Breast cancer, metastatic
Topics Breast Cancer
Presenter Matthew Ellis
Citation Annals of Oncology (2016) 27 (6): 1-36. 10.1093/annonc/mdw435
Authors M.J. Ellis1, I. Bondarenko2, E. Trishkina3, M. Dvorkin4, L. Panasci5, A. Manikhas6, Y. Shparyk7, S. Cardona-Huerta8, K. Cheung9, M.J. Philco-Salas10, M. Ruiz-Borrego11, Z. Shao12, S. Noguchi13, L.M. Grinsted14, M. Fazal15, M. Stuart16, J.F. Robertson9
  • 1Lester And Sue Smith Breast Center, Baylor Clinic, Baylor College of Medicine, 77030 - Houston/US
  • 2Oncology Department, Dnipropetrovsk State Medical Academy, 49102 - Dnipropetrovsk/UA
  • 3Department Of Oncology, Leningrad Regional Oncology Centre, St-Petersburg/RU
  • 4Department Of Oncology, Clinical Oncology Dispensary, Omsk/RU
  • 5Department Of Oncology, Jewish General Hospital, Montreal/CA
  • 6City Clinical Oncology Dispensary, City Clinical Oncology Center, 198255 - St. Petersburg/RU
  • 7Department Of Chemotherapy, Lviv State Oncology Regional Treatment and Diagnostic Centre, 79031 - Lviv/UA
  • 8Technologico De Monterrey, Hospital San Jose, Monterrey/MX
  • 9Division Of Medical Sciences And Graduate Entry Medicine, University of Nottingham, Derby/GB
  • 10Instituto Oncológico De Lima, Unidad de Investigación, Lima/PE
  • 11Department Of Oncology, Hospital Universitario Virgen del Rocio, Sevilla/ES
  • 12Shanghai Cancer Center, Fudan University, Shanghai/CN
  • 13Department Of Breast And Endocrine Surgery, Osaka University Graduate School of Medicine, Osaka/JP
  • 14Global Medicines Development, AstraZeneca, Cambridge/GB
  • 15Global Medicines Development, AstraZeneca, Gaithersburg/US
  • 16Global Medicines Development, AstraZeneca, Macclesfield/GB

Abstract

Background

This Phase III, randomised, double-blind, multicentre trial (FALCON; NCT01602380) compared the selective estrogen receptor (ER) degrader (SERD) fulvestrant with anastrozole in patients with ER- and/or progesterone receptor-positive locally advanced or metastatic breast cancer who had not received prior hormonal therapy.

Methods

Patients were randomised 1:1 to fulvestrant (500 mg IM on Days 0, 14, 28, then each 28 days) or anastrozole (1 mg daily). The primary endpoint was progression-free survival (PFS), assessed via RECIST 1.1, surgery/radiotherapy for disease worsening, or death. Secondary endpoints were: overall survival (OS); objective response rate (ORR, complete response [CR] or partial response [PR]); duration of response (DoR); expected DoR (EDoR); clinical benefit rate (CBR; CR, PR, or stable disease ≥24 weeks); duration of clinical benefit (DoCB); expected DoCB (EDoCB); health-related quality of life (HRQoL); and safety.

Results

In total, 462 patients (fulvestrant, n = 230; anastrozole, n = 232) were randomised. The primary endpoint was met as shown by a statistically significant improvement in PFS with fulvestrant vs. anastrozole (hazard ratio 0.797 [95% confidence interval 0.637, 0.999]; p = 0.0486; median PFS, 16.6 vs. 13.8 months, respectively). Secondary outcomes are shown in the Table (OS maturity was 31% at a median follow-up of 25.0 months). Treatment impact on HRQoL was similar in both treatment groups. The most common adverse events were arthralgia (16.7% vs. 10.3%) and hot flushes (11.4% vs. 10.3%) for fulvestrant and anastrozole, respectively.

Conclusions

These results confirm the superior efficacy of fulvestrant over anastrozole in postmenopausal women with hormone receptor-positive locally advanced or metastatic breast cancer who have not received prior hormonal therapy.

Clinical trial identification

ClinicalTrials.gov identifier: NCT01602380

Legal entity responsible for the study

AstraZeneca

Funding

AstraZeneca

Disclosure

M.J. Ellis: Employment, leadership, stock or other ownership, patents, royalties or intellectual property - Bioclassifier LLC; Consulting or advisory role - AstraZeneca, Pfizer, Novartis, Celgene. K-L. Cheung: Honoraria, speakers bureau - Chugai: Research Funding–AstraZeneca. S. Noguchi: Honoraria, consulting or advisory role–AstraZeneca, Chugai, Nippon Kayaku, Novartis, Pfizer, Taiho; Research funding – AstraZeneca, Chugai, Nippon Kayaku, Novartis, Pfizer, Taiho, Takeda; Patents, royalties or intellectual property – Sysmex. L.M. Grinsted: Employment, stock or other ownership – AstraZeneca. M. Fazal: Employment – AstraZeneca. M. Stuart: Former employment, and current stock or other ownership – AstraZeneca; Current employment – Kingston Oncology Ltd. J.F. Robertson: Stock or other ownership – Oncimmune; Honoraria, consulting or advisory role, travel or expenses – AstraZeneca, Bayer AG; Research funding – AstraZeneca, Bayer AG, Novartis; Expert testimony – AstraZeneca. All other authors have declared no conflicts of interest.

Secondary endpoint Fulvestrant (N = 230) Anastrozole (N = 232)
OS maturity (% deaths) 29.1% 32.3% Hazard ratio (95% CI) 0.88 (0.63, 1.22); p = 0.428
ORR 46.1% [89/193] 44.9% [88/196] Odds ratio (95% CI) 1.07 (0.72, 1.61); p = 0.729
Median DoR 20.0 months 13.2 months -
EDoR 11.4 months 7.5 months Ratio (95% CI) 1.52 (1.23, 1.89); p < 0.001
CBR 78.3% [180/230] 74.1% [172/232] Odds ratio (95% CI) 1.25 (0.82, 1.93); p = 0.305
CR 3.0% [7/230] 3.4% [8/232] -
PR 37.4% [86/230] 35.3% [82/232] -
SD ≥24 weeks 37.8% [87/230] 35.3% [82/232] -
Median DoCB 22.1 months 19.1 months -
EDoCB 21.9 months 17.5 months Ratio (95% CI) 1.26 (1.13, 1.39); p < 0.001