Dr. Baselga Compares mTOR Inhibitors in Breast Cancer
Jose Baselga, MD, PhD
Published Online: Monday, December 3, 2012
José Baselga, MD, PhD, Physician-in-Chief, Memorial Sloan-Kettering Cancer Center, compares results from two trials analyzing the mTOR inhibitors temsirolimus and everolimus in breast cancer.
A phase II trial looked at a 25 mg/week dose of temsirolimus in patients with pretreated breast cancer who tested positive for ER, PR or HER2. The study found that temsirolimus as a single agent has minimal activity. However, the BOLERO-2 study that analyzed everolimus at 10 mg/day and exemestane at 25 mg/day for postmenopausal patients achieved its primary endpoint of progression-free survival.
Baselga says that the oncology community is trying to determine why temsirolimus and everolimus, both mTOR inhibitors, produced vastly different results in similar studies.
Baselga suggests that everolimus could only be working in patients with refractory disease. A more likely reason of the variance in results, according to Baselga, is dosing differences, which could explain the lower rate of mucositis in the temsirolimus study.
Although the potential for next-generation sequencing of breast cancer tumors to improve treatment strategies is widely recognized, questions swirl about the optimal use of such increasingly available technologies in clinical practice for today’s patients.
A wide-ranging analysis of more than 5500 breast cancer tumors that combined genomic and protein expression testing has identified promising targets to explore for treating patients with poor prognoses, with particularly notable findings involving androgen receptor (AR) expression