A pivotal Phase III study shows Afinitor® (everolimus) tablets plus exemestane, a hormonal therapy, more than doubled the time women lived without tumor growth (progression-free survival; PFS) and significantly reduced the risk of cancer progression by 57% versus exemestane alone in patients with advanced breast cancer.
"Everolimus is the first drug to show significant efficacy when combined with hormonal therapy in women with ER+HER2- advanced breast cancer, where there continues to be a critical unmet need," said Herve Hoppenot, President, Novartis Oncology. "The magnitude of benefit seen in these patients, despite their resistance to previous hormonal therapies, shows everolimus represents a potential important new treatment approach."
BOLERO-2 (Breast cancer trials of OraL EveROlimus-2) examined the safety and efficacy of everolimus in combination with exemestane versus exemestane alone in postmenopausal women with ER+HER2- advanced breast cancer who recurred or progressed while on or following previous treatment with hormonal therapies, letrozole or anastrozole. Findings from the trial will be presented today during a Presidential Symposium at the 2011 European Multidisciplinary Cancer Congress in Stockholm, Sweden.
At a pre-planned analysis, the trial met its primary endpoint of PFS showing treatment with everolimus improved PFS to 6.9 months compared to 2.8 months (hazard ratio 0.43 [95% confidence interval (CI): 0.35 to 0.54]; p<0.0001) by local investigator assessment. This significant improvement was consistent across all subgroups including number of prior therapies, presence of visceral disease, bone metastases and prior use of chemotherapy.
Hormonal therapy remains the cornerstone of treatment for women with advanced breast cancer but most women with metastatic disease do not respond to initial treatment with hormonal therapy, and almost all initial responders develop resistance. Additionally, life expectancy is significantly shortened due to the worsening of the disease.
Everolimus targets mTOR in cancer cells, a protein that acts as an important regulator of tumor cell division, blood vessel growth and cell metabolism. Resistance to hormonal therapy in breast cancer has been associated with over-activation of the mTOR pathway.
Data from BOLERO-2 support worldwide regulatory submissions, which are planned by the end of 2011. Additional data from BOLERO-2 will be presented at upcoming medical congresses this year.
SOURCE Novartis Pharmaceuticals Corporation