Double-Blind, Randomized Placebo Controlled Trial of Fulvestrant Compared With Exemestane After Prior Nonsteroidal Aromatase Inhibitor Therapy in Postmenopausal Women With Hormone Receptor-Positive, Advanced Breast Cancer: Results From EFECT.

Author(s): Chia S, Gradishar W, Mauriac L, Bines J, Amant F, Federico M, Fein L, Romieu G, Buzdar A, Robertson JF, Brufsky A, Possinger K, Rennie P, Sapunar F, Lowe E, Piccart M

Affiliation(s): Division of Medical Oncology, British Columbia Cancer Agency, University of British Columbia, Vancouver, British Columbia, Canada; Division of Hematology and Medical Oncology, Feinberg School of Medicine, Northwestern University, Chicago, IL; Department of Medical Oncology, Institut Bergonie, Bordeaux; Department of Medical Oncology, CRLC Val d' Aurelle- Paul Lamarque, Montpellier, France; Medical Oncology, Instituto National de Cancer, Rio de Janeiro; Departmento de Radiologia, Faculdade de Medicina da USP, University of Sao Paulo, Sao Paulo, Brazil; Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University Hospitals Leuven, Leuven; Medicine Department, Jules Bordet Institute, Brussels, Belgium; Investigacion Clinica, Centro Oncologico de Rosario, Rosario, Argentina; M.D. Anderson Cancer Center, University of Texas, Houston, TX; Professorial Unit of Surgery, Nottingham City Hospital, Nottingham; Clinical Development, AstraZeneca Pharmaceuticals, Macclesfield, Cheshire, United Kingdom; Division of Hematology/ Oncology, University of Pittsburgh School of Medicine, Pittsburg, PA; Department of Oncology and Haematology, Charite Campus Mitte, Universitatsmedizin, Berlin, Germany; and Clinical Development, AstraZeneca Pharmaceuticals, Wilmington, DE.

Publication date & source: 2008-03-03, J Clin Oncol., [Epub ahead of print]

Publication type:

PURPOSE: The third-generation nonsteroidal aromatase inhibitors (AIs) are increasingly used as adjuvant and first-line advanced therapy for postmenopausal, hormone receptor-positive (HR+) breast cancer. Because many patients subsequently experience progression or relapse, it is important to identify agents with efficacy after AI failure. Materials and METHODS: Evaluation of Faslodex versus Exemestane Clinical Trial (EFECT) is a randomized, double-blind, placebo controlled, multicenter phase III trial of fulvestrant versus exemestane in postmenopausal women with HR+ advanced breast cancer (ABC) progressing or recurring after nonsteroidal AI. The primary end point was time to progression (TTP). A fulvestrant loading-dose (LD) regimen was used: 500 mg intramuscularly on day 0, 250 mg on days 14, 28, and 250 mg every 28 days thereafter. Exemestane 25 mg orally was administered once daily. RESULTS: A total of 693 women were randomly assigned to fulvestrant (n = 351) or exemestane (n = 342). Approximately 60% of patients had received at least two prior endocrine therapies. Median TTP was 3.7 months in both groups (hazard ratio = 0.963; 95% CI, 0.819 to 1.133; P = .6531). The overall response rate (7.4% v 6.7%; P = .736) and clinical benefit rate (32.2% v 31.5%; P = .853) were similar between fulvestrant and exemestane respectively. Median duration of clinical benefit was 9.3 and 8.3 months, respectively. Both treatments were well tolerated, with no significant differences in the incidence of adverse events or quality of life. Pharmacokinetic data confirm that steady-state was reached within 1 month with the LD schedule of fulvestrant. CONCLUSION: Fulvestrant LD and exemestane are equally active and well-tolerated in a meaningful proportion of postmenopausal women with ABC who have experienced progression or recurrence during treatment with a nonsteroidal AI.