Two New England Journal of Medicine papers reporting the results of separate Phase III clinical trials for the treatment of advanced breast cancer recently received early, online first release because the studies were presented at the December 2011 CTRC-AACR San Antonio Breast Cancer Symposium. José Baselga, MD, PhD, chief of the Division of Hematology/Oncology at Massachusetts General Hospital, and Associate Director of the Mass General Cancer Center, is the lead and corresponding author of the papers.
BOLERO-2 : A Phase III clinical trial of combined treatment with everolimus (Affinitor, a kidney cancer drug) and exemestane (Aromasin, an aromatase inhibitor) for treatment of postmenopausal women with advanced, HER2-negative, estrogen-receptor-positive breast cancer, whose tumors had stopped responding to hormone-blocking therapies like exemestane.
The study found that combined treatment with both drugs increased progression-free survival an average of seven months, compared with patients receiving exemestane and a placebo. Preliminary results of the study, which was halted early when an interim analysis showed significant benefit for the participants receiving both drugs, were presented at the European Multidisciplinary Cancer Congress in September 2011. The study was funded by Novartis, which manufactures everolimus.
CLEOPATRA: A Phase III clinical trial of adding pertuzumab (an investigational anti-HER2 monoclonal antibody) to combined treatment with trastuzumab (the anti-HER2 monoclonal antibody Herceptin) and docetaxel (the anticancer drug Taxotere) as first-line treatment for women with HER2-positive metastatic breast cancer. The HER2 receptor protein is over-expressed in about 20 percent of breast cancers, driving continued tumor growth.
Trial results indicate that the addition of pertuzumab extended progression-free survival an average of six months, compared with treatment with two drugs only. Although pertuzumab and trastuzumab both bind to HER2 and block its signal, pertuzumab suppresses the receptor's binding to the HER3 receptor, an interaction essential to transmission of the cell-growth signal. The study was funded by Roche subsidiary Genentech.
"These two studies are groundbreaking," says Baselga, who also is a Professor of Medicine at Harvard Medical School. "Not only are they likely to change treatment practice for about 80 percent of the breast cancer patient population with advanced metastatic disease, but I'm also hopeful that these results will open the floodgates for new approaches in treatment for newly diagnosed, early-stage patients, eventually leading to therapies that will cure and not just control these cancers."
Mass General media contacts:
Katie Marquedant, (617) 314-3986 (mobile), firstname.lastname@example.org
Sue McGreevey, 617 724-2764, email@example.com