EAST HANOVER, N.J., Dec. 9, 2010 /PRNewswire/ -- A new study shows that the addition of everolimus (Afinitor® tablets) to the hormonal therapy tamoxifen in patients with hormone-receptor positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) metastatic breast cancer who have been previously treated with an aromatase inhibitor (AI) delays disease progression compared to tamoxifen alone. These results were presented today at the 33rd Annual CTRC-AACR San Antonio Breast Cancer Symposium in San Antonio, Texas(1).
Findings from a randomized, Phase II study of 111 patients showed the proportion of metastatic breast cancer patients without tumor progression at six months was 61.1% for those taking everolimus plus tamoxifen (95% confidence interval [CI], 46.9 to 74.1) versus 42.1% for patients treated with tamoxifen alone (95% CI, 29.1 to 55.9); p=0.045(1).
Disease progression was delayed by a median of 8.6 months in patients treated with the combination versus 4.5 months in patients treated with tamoxifen alone, with everolimus in combination with tamoxifen providing a statistically significant reduction in the risk of disease progression by 47% (hazard ratio=0.53 [95% CI, 0.35 to 0.81]; log-rank test: p=0.0026, exploratory analysis). Side effects were generally manageable in both study arms. As of October 2010, there were 25 patient deaths in the tamoxifen arm versus nine in the everolimus plus tamoxifen arm (hazard ratio=0.32 [95% CI, 0.15 to 0.68]; log-rank test: p=0.0019)(1).
This Phase II trial is conducted by the Groupe d'Investigateurs Nationaux pour l'Etude des Cancers Ovariens et du sein (the French GINECO Group).
Everolimus is an investigational agent for the treatment of patients with breast cancer. Everolimus targets mTOR in cancer cells, a protein that acts as an important regulator of tumor cell division, blood vessel growth and cell metabolism(7,8).
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