Predicting breast cancer drug response by 20/20 GeneSystems’ PredicTOR test

20/20 GeneSystems, Inc. (www.2020gene.com) will present results this week at the Breast Cancer Symposium 2012 (San Francisco) of a 45 patient study showing the usefulness of its PredicTOR ™ test in predicting response of breast tumors to the drug Herceptin®. That drug blocks the HER2 pathway which is activated in many breast tumors. However, about half of breast tumors treated with Herceptin® do not respond to that drug, often because a second cancer causing pathway, mTOR, is also active. 20/20's PredicTOR™ test measures key proteins in the mTOR pathway in order to suggest that tumors may also benefit from treatment with a drug that targets that pathway.

Using tumors surgically removed prior to Herceptin® therapy, the 20/20 test correctly classified 28 of 32 tumors that ultimately responded to the drug and 10 of 13 tumors that failed to respond. The company plans to further validate the test in the coming months using samples from several hundred patients, and if successful, hopes to make its test available to oncologists by this time next year. Those patients with a positive PredicTOR ™ score would likely be prescribed an mTOR inhibitor in addition to Herceptin®. Currently two drugs that target mTOR are approved in the U.S. with several others in late stage development.

"The mTOR pathway is of large interest in personalized cancer therapy and breast cancer in particular. A number of pharmaceutical companies, including Pfizer and Novartis, are commercializing mTOR inhibitors, "says Saranya Chumsri, M.D., an Assistant Professor and oncologist in the Breast Cancer unit at the Greenebaum Cancer Center, University of Maryland. "These drugs can be very powerful but they are highly targeted and do have concerning side effects. It may only work in small subsets of patient populations. A test identifying likely responders could be of tremendous value to personalized oncology."

PredicTOR ™ was developed using 20/20's patented layered immunohistochemistry technology, which measures multiple protein biomarkers in standard formalin-fixed paraffin-embedded tissue sections.

Source: 20/20 GeneSystems, Inc.