Targeting breast cancer

Sunnybrook researchers recently helped bring in a new era in the treatment of advanced breast cancer, with future implications for earlier stages, and other cancers.

There has been a shift in cancer treatment with the development of technology to attach chemotherapy to targeted therapy — a concept termed antibody-drug conjugate. This approach harnesses the benefits of targeted therapy (aimed solely at cancers cells) but allows new, direct delivery of chemotherapy to cancer cells. Standard treatment combines targeted therapy, and traditional chemotherapy that introduces side effects.

Dr. Sunil Verma led a large international Phase III clinical trial, called EMILIA, for advanced HER2 positive breast cancer. Results published in the New England Journal of Medicine showed patients on the antibody-drug conjugate trastuzumab emtansine (T-DM1) had improved survival with significantly reduced toxicity, compared with standard treatment.

The antibody-drug conjugate tested in the EMILIA clinical trial, T-DM1 (Trastuzumab emtansine) was approved by Health Canada on September 11th, 2013.

"These dramatic improvements mean longer survival with better quality of life. We are now exploring this approach in early stage disease," says Dr. Verma, first author of the EMILIA study and chair, breast medical oncology and head, Breast Clinical Trials at the Louise Temerty Breast Cancer Centre.

He and others are also researching targeted therapies to block cancer cell resistance in hormone receptor positive breast cancers, about 70 per cent of breast cancer patients. For Triple Negative, newer generations of drugs that damage cancer cell DNA are also being explored.