This week, breast cancer researchers have been reporting encouraging clinical trial results with the drug everolimus at the San Antonio Breast Cancer Symposium. Everolimus is a mTOR inhibitor, first approved by the FDA for treatment of kidney cancer and then for post-transplant control of the immune system.
Ruth O’Regan, MD, director of the Translational Breast Cancer Research Program at Winship Cancer Institute, has led clinical studies of everolimusÂ in breast cancerÂ and has championed the strategy of combining mTOR inhibitors with current treatments for breast cancer.
She recently explained the rationale to the NCI Cancer Bulletin:
She views the combination therapy as a potential alternative to chemotherapy for treating ER-positive advanced breast cancer when hormonal therapies have stopped working.
When resistance to hormonal therapies occurs, Dr. O’Regan explained, additional signaling pathways become activated. Unlike chemotherapy, which targets rapidly dividing cells, mTOR inhibitors are an example of the kind of treatment that may block growth-promoting signaling pathways.
Currently, Winship researchers are examining a combination involving everolimus and the EGFR inhibitor lapatinib for “triple-negative” breast cancer, a particularly aggressive and difficult-to-treat variety.