The original results published in NEJM today showed that at a pre-planned interim analysis, BOLERO-2 met its primary endpoint of PFS showing treatment with everolimus plus hormonal therapy extended PFS to 6.9 months compared to 2.8 months with hormonal therapy alone (hazard).

The side effects observed were consistent with those previously reported with everolimus with the most common Grade 3 or 4 adverse events including: stomatitis (8% vs. 1%), anemia (7% vs. 1%), hyperglycemia (5% vs. <1%), dyspnea (4% vs. 1%), fatigue (4% vs. 1%) and pneumonitis (3% vs. 0%) for the combination and exemestane-only arms, respectively. At the time of updated analysis, 137 patients died, constituting 17.2% of patients in the everolimus plus exemestane arm and 22.7% of those in the exemestane-only arm.

Hormonal therapy remains the cornerstone of treatment for women with advanced breast cancer but almost all patients who respond eventually develop resistance. Everolimus targets the mTOR pathway in cancer cells. mTOR is 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.

Each year, around 220,000 women globally will be diagnosed with ER+HER2- advanced breast cancer. Everolimus is also being investigated for the treatment of patients with HER2+ advanced breast cancer.

Regulatory submissions for everolimus based on the BOLERO-2 results are planned by the end of 2011.

SOURCE Novartis