Everolimus in combination with exemestane in the treatment of postmenopausal women with estrogen receptor-positive metastatic breast cancer who are refractory to letrozole or anastrozole: Preliminary results of the BOLERO-2 trial.

Breast Cancer - HER2/ER
Session Type and Session Title: 
This abstract will not be presented at the 2011 ASCO Annual Meeting but has been published in conjunction with the meeting.
Abstract Number: 


J Clin Oncol 29: 2011 (suppl; abstr e11058)
J. Baselga, M. Campone, M. J. Piccart-Gebhart, H. A. Burris, H. S. Rugo, S. Noguchi, M. Gnant, K. I. Pritchard, F. Lebrun, J. T. Beck, Y. Ito, D. A. Yardley, I. Deleu, A. Perez, T. D. Bachelot, L. Vittori, P. Mukhopadhyay, D. Weber, T. Sahmoud, G. N. Hortobagyi; Vall d'Hebron Institute of Oncology, Vall d'Hebron University Hospital, Barcelona, Spain; Centre René Gauducheau, Saint-Herblain, France; Jules Bordet Institute, Brussels, Belgium; Sarah Cannon Research Institute, Nashville, TN; University of California San Francisco, San Francisco, CA; Osaka University, Osaka, Japan; Department of Surgery, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria; Sunnybrook Odette Cancer Centre and the University of Toronto, Toronto, ON, Canada; Institut Jules Bordet, Brussels, Belgium; Highlands Oncology Group, Fayetteville, AR; Cancer Institute Hospital of the Japanese Foundation for Cancer Research, Tokyo, Japan; Oncology Centre, AZ Nikolaas, Sint-Niklaas, Belgium; Memorial Cancer Institute, Hollywood, FL; Centre Leon Berard, Lyon, France; Novartis Pharma AG, Basel, Switzerland; Novartis Pharmaceuticals Corporation, East Hanover, NJ; Novartis Pharmaceuticals Corporation, Florham Park, NJ; University of Texas M. D. Anderson Cancer Center, Houston, TX

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Abstract Disclosures


Background: The PI3K/Akt/mTOR pathway, a key regulator of cellular proliferation, cellular metabolism, and angiogenesis, is constitutively activated in aromatase inhibitor–resistant breast cancer. Everolimus (EVE), an inhibitor of the PI3K/Akt/mTOR pathway, has single-agent activity and provides additional efficacy to long-term estrogen deprivation when combined with letrozole in the neoadjuvant setting. Combination of EVE and exemestane may improve outcomes for patients ER+ breast cancer refractory to nonsteroidal aromatase inhibitors (NSAI). Methods: In this multinational, double-blind, placebo-controlled phase III study, postmenopausal women ≥18 years old with ER+ locally advanced or metastatic breast cancer whose disease was refractory to NSAI and documented recurrence or progression were stratified by sensitivity to prior hormonal therapy and the presence of visceral metastasis and then randomized (2:1) to EVE (10 mg daily) or matching placebo orally once daily, with both arms receiving exemestane (25 mg daily). Treatment was continued until disease progression or unacceptable toxicity. The primary outcome was progression-free survival (PFS) assessed by the investigators. Secondary outcomes included overall survival, overall response rate, time to deterioration of ECOG performance status, safety, and change in QoL scores over time. Between June 2009 and January 2011, 723 patients were randomized from 24 countries; 84% had hormone sensitive-disease and 56% had visceral disease. An interim analysis based on safety and efficacy reviewed by the independent data monitoring committee will be performed when 317 PFS events have occurred. The IDMC meeting is planned for May 2011.