The investigational drug, Trastuzumab Emtansine (T-DM1), improves survival of patients with HER2-Positive metastatic breast cancer “significantly”, Genentech Inc. announced today as it published highlights of its Phase III EMILIA study results. T-DM1 was compared to lapatinib and Xeloda (capecitabine) combination therapy. The EMILIA study has met both of its co-primary endpoints: progression-free survival and significant improvements in overall survival, the company added.

Genentech, based in California, USA, is part of the Roche Group. Both companies announced that full study data will be presented at a medical meeting soon.

A BLA (Biologics License Application) has been submitted to the US FDA (Food and Drug Administration) by Genentech. Roche says it will soon do the same with EMA (the European Medicines Agency).

Hal Barron, M.D., chief medical officer and head, Global Product Development, said:

“We are extremely pleased to announce that people treated with trastuzumab emtansine survived significantly longer than those who received a standard option for this aggressive advanced breast cancer. We believe that antibody-drug conjugates have the potential to change the future treatment of cancer, and we look forward to working with regulatory authorities in the hope of bringing another potential treatment option to people with HER2-positive metastatic breast cancer.”

Trial participants in the lapatinib and Xeloda arm of the study will be able to switch over to trastuzumab emtansine if they wish. Genentech says that there are plans underway to initiate an EAP (Expanded Access Progam) in the USA so that under certain circumstances, patients with HER2-Positive metastatic breast cancer may have access to the investigational drug before it is finally approved.

Trastuzumab emtansine, an antibody-drug conjugate, has been studied by Genentech for patients with HER2-positive cancers. It is a combination of the chemotherapy DM1 and antibody trastuzumab; a stable linker was used to attach the two together.

Scientists designed trastuzumab emtansine to target and inhibit HER2 signaling, and to deliver the DM1 chemotherapy directly within the HER2-positive cancer cells.

Genentech says that its scientists have been investigating the HER2 pathway for over thirty years. The company says that “The development of HER2-targeted therapies represents one of the first successful examples of personalized healthcare”.

This is a Phase III, open label, randomized study which compares trastuzumab emtansine alone with a lapatinib/Xeloda combo. All the 911 participants have HER2-positive locally advanced or metastatic breast cancer. They had already received Herceptin and a traxane-based chemotherapy.

EMILIA has two (co-primary) endpoints: 1. Progression-free survival, and 2. Overall survival. Other endpoints include quality of life, one/two year survival rates, safety profile, duration of response, and objective response rate.

Globally, breast cancer is the most common cancer to affect adult females. 229,000 patients will be diagnosed with cancer in 2012 and 40,000 will die from it, says the American Cancer Society.

Higher levels of HER2 (Human Epidermal growth factor Receptor 2) are present on the surface of the tumor cells in patients with HER2-positive breast cancer.

Approximately 1 in every 4 breast cancer cases is of the HER2-positive type.

Roche, a major player in the cancer drugs market, is looking for a replacement for Herceptin, its third best-selling drug. In 2015 Herceptin will have to face competition from “biosimilar” generic makers. The company hopes T-DM1 may make up for the expected drop in Herceptin sales in 2015.

Written by Christian Nordvist