Treating postmenopausal women with advanced breast cancer resistant to hormonal therapy with a combination of 2 existing cancer drugs significantly improves outcome, according to results from a phase 3 clinical trial. Researchers reported at the 2011 European Multidisciplinary Cancer Congress* that women had a progression-free survival of nearly 7 months when treated with a combination of everolimus and exemestane compared to women who received only exemestane.
The trial’s lead, Professor José Baselga, from the Massachusetts General Hospital and Harvard Medical School, Boston, said, “These results are impressive and, potentially, could represent a new therapeutic option for women with advanced postmenopausal breast cancer who have previously been treated with hormonal therapy.”
The phase 3 clinical trial, BOLERO 2, was created to determine the effectiveness of everolimus in patients who have developed resistance to aromatase inhibitors. The multinational trial involved 724 patients, with an average age of 62, living in 24 countries. Previous treatments for all trial patients included the aromatase inhibitors letrozole or anastrozole. Earlier treatments of tamoxifen (48% of patients), fulvestrant (16% of patients), and chemotherapy (68% of patients) were also included.
A randomized group of 485 patients received everolimus and exemestane. Another 239 patients were given only exemestane until the disease progressed or unacceptable levels of toxicity were documented. The trial ended prematurely, after an interim analysis revealed a lack of tumor growth for nearly 11 months in patients who received everolimus, yet patients treated with only exemestane had progression-free survival for only about 4 months.
Baselga says, “This is a highly significant improvement in the time to disease progression in a patient population that is highly resistant to therapy.”
*The 2011 European Multidisciplinary Cancer Congress is the 16th congress of the European CanCer Organisation (ECCO), the 36th congress of the European Society for Medical Oncology (ESMO) and the 30th congress of European Society for Therapeutic Radiology and Oncology (ESTRO).
Source: ECCO