FOR IMMEDIATE RELEASE

Novel Approach in Targeted Treatment Offers New Hope in Breast Cancer

Toronto (June 4, 2012) — For the first time in cancer treatment, researchers demonstrate the effectiveness of a new way to attach chemotherapy to trastuzumab (T-DM1, trastuzumab emtansine). This antibody drug link or conjugate allows for chemotherapy to be carried or delivered right to cancer cells and is associated with reduced toxicity for patients.

"These findings mean a new direction for the treatment of cancers, and potentially for earlier stages of disease, by improving the way chemotherapies can now be combined with targeted therapies and can be delivered more directly to the cancer cells," says Dr. Sunil Verma, EMILIA study senior author and Chair, Breast Medical Oncology at Sunnybrook's Odette Cancer Centre. The EMILIA clinical trial is a large, randomized, multi-national Phase III study evaluating T-DM1 versus Xeloda® (capecitabine) and lapatinib, for patients with advanced or metastatic breast cancer overexpressing HER2 (ErbB2). The results from this pivotal trial were presented today at the Plenary Session at the American Society of Clinical Oncology Annual Meeting.

Chemotherapy drugs are effective in killing cancer cells but therapy may also harm healthy cells and results in significant side effects for the patient. Targeted therapies or monoclonal antibody drugs such as trastuzumab or lapatinib are used to block the growth of cancer cells and are traditionally delivered along with standard chemotherapy agents. Trastuzumab emtansine (T-DM1), a new way of linking the chemotherapy to the targeted drug trastuzumab, allows for a more directed delivery of chemotherapy to the cancer cell. T-DM1 is made up of the antibody trastuzumab and the chemotherapy DM1 attached together using a stable linker molecule.

Study findings indicate that T-DM1 was efficacious and well tolerated. The study showed that the risk of disease worsening, or risk of death (progression-free survival; PFS), was reduced by 35 percent for people who received T-DM1 compared to those who received lapatinib plus Xeloda® (capecitabine) chemotherapy (HR=0.65, p-value <.0001). There was also a trend for patients who received T-DM1 for better overall survival (OS, the other co-primary endpoint of the study) than those who received lapatinib plus Xeloda®, but these data are currently not mature.

The EMILIA clinical trial Phase III study was conducted across 26 countries in 213 centres, with 991 patients diagnosed with advanced or metastatic breast cancer.

According to the Canadian Cancer Society, an estimated 23,400 Canadians will be diagnosed with breast cancer, and an estimated 5,100 will have died of the disease in 2011. HER2 positive breast cancer accounts for approximately 20 per cent of breast cancers that overexpress the HER2 receptor.

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Media contact:
Natalie Chung-Sayers
Sunnybrook
416-480-4040