Traditional chemotherapy drugs are often given in combination to increase their effectiveness, but doctors and medical researchers have struggled to implement new targeted cancer drugs in the same way. Research conducted on patients with advanced breast cancer by Kimberly Blackwell '89, associate professor of medicine, may change that.
Blackwell studied patients whose tumors tested positive for HER2, a protein indicating aggressive breast cancer, and for whom chemotherapy was not effective. Those taking the targeted drugs lapatinib and trastuzumab in combination lived an average of twenty weeks longer than those who took lapatinib alone.
Blackwell says trastuzumab binds to and blocks part of the HER2 growth factor that appears on the surface of some breast cancer cells while lapatinib binds to a second growth factor, EGFR, and part of HER2 that sits below the cell surface. "It's sort of a double whammy, disabling the HER2 protein in two places instead of one," she says.
This clinical trial is the first time that a pair of targeted drugs has been shown to be more effective than an approach combining chemotherapy and targeted drugs. According to Blackwell, this could be the first step toward a chemotherapy-free future.