RESUMET-DM1 is the first of an experimental new cancer drug known as an antibody-drug conjugate. It demonstrates an improvement in progression-free survival over standard therapy in HER2-positive metastatic breast cancer. It combines two existing cancer drugs in order to deliver both drugs specifically to cancer cells: Trastuzumab, a monoclonal antibody to target cells that overproduce the HER2 protein; and, T-DM1 is a chemotherapeutic substance.This is the first ever presentation of an anti-HER2 antibody-drug conjugate used as a primary treatment for patients with advanced breast cancer," said Professor Perez. "We are encouraged by the results. The study explained that T-DM1 has very good anti-tumor activity as well as much lower toxicity when evaluated side-by-side to the older "standard". T-DM1 has displayed promising activity in preclinical studies.