Roche announces positive Phase II results for trastuzumab emtansine (T-DM1) in HER2-positive metastatic breast cancer

Basel, 07 April 2011


Roche (SIX: RO, ROG; OTCQX: RHHBY) today announced topline results of its first randomized trial of trastuzumab emtansine (T-DM1) in HER2-positive metastatic breast cancer. The Phase II trial, known as TDM4450g, compared trastuzumab emtansine (T-DM1) single agent to the combination of Herceptin (trastuzumab) and chemotherapy (docetaxel) in previously untreated patients. The results showed that patients treated with trastuzumab emtansine ( T-DM1 ) in this study lived significantly longer with their disease under control (PFS) and experienced fewer side effects typical of chemotherapy.

“These encouraging data support our ongoing development program for trastuzumab emtansine (T-DM1) in first-line HER2-positive metastatic breast cancer,’’ said Hal Barron, M.D., Chief Medical Officer and Head of Global Development. “Trastuzumab emtansine (T-DM1) is a novel treatment with the potential to improve outcomes for patients with HER2-positive breast cancer due to its efficacy and favourable safety profile.”

Data from the TDM4450g study will be submitted for presentation at a future medical congress.

An earlier analysis of this study presented at the 35th Congress of the European Society of Medical Oncology (ESMO) in 20101 showed encouraging results in tumour shrinkage (overall response rate ORR) in patients with a minimum of 4 months of follow-up. In addition, the study showed that trastuzumab emtansine (T-DM1) significantly reduced the burden of typical side effects associated with conventional chemotherapy.

About Breast Cancer

Breast cancer is the most common cancer among women worldwide. Each year about 1.4 million new cases of breast cancer are diagnosed worldwide, and over 450,000 people will die of the disease annually2.

In HER2-positive breast cancer, increased quantities of the HER2 receptor are present on the surface of the tumour cells. This is known as ‘HER2 positivity’ and affects approximately 15-25 percent of women with breast cancer.

About the TDM4450g study

The TDM4450g Phase II study is a randomized, multicentre international, two-arm, open-label clinical trial including 137 patients with first-line HER2-positive metastatic breast cancer. Patients from approximately 64 sites were randomized to receive either trastuzumab emtansine (T-DM1) or Herceptin and chemotherapy (docetaxel). The primary endpoints of the study were progression-free survival (PFS) and safety. Secondary endpoints include, objective response, duration of objective response, and clinical benefit rate.

About trastuzumab emtansine (T-DM1)

Trastuzumab emtansine (the generic, or International Non-proprietary Name for T-DM1) is an antibody-drug conjugate (ADC), being studied for HER2-positive metastatic breast cancer. Due to their targeted nature, ADC s allow for the administration of a highly potent, otherwise intolerable , cytotoxic agent.

Because a stable linker is used, the ADC largely remains intact outside the cancer cell, with the cytotoxic agent in an inactive state until it enters the cancer cell, thereby minimising exposure of normal cells to the chemotherapy. The humanized monoclonal antibody (trastuzumab) binds to the HER2-positive cancer cells, and is thought to block out of control signals that contribute to cancer growth and survival while also calling on the body’s immune system to attack the cells. After binding, trastuzumab emtansine (T-DM1) is internalized into those cancer cells, DM1 containing metabolites of the conjugate specifically destroy the cells.

Genentech, a member of the Roche Group, licenses technology for trastuzumab emtansine (T-DM1) under an agreement with ImmunoGen, Inc.

About Roche

Headquartered in Basel, Switzerland, Roche is a leader in research-focused healthcare with combined strengths in pharmaceuticals and diagnostics. Roche is the world’s largest biotech company with truly differentiated medicines in oncology, virology, inflammation, metabolism and CNS. Roche is also the world leader in in-vitro diagnostics, tissue-based cancer diagnostics and a pioneer in diabetes management. Roche’s personalised healthcare strategy aims at providing medicines and diagnostic tools that enable tangible improvements in the health, quality of life and survival of patients. In 2010, Roche had over 80’000 employees worldwide and invested over 9 billion Swiss francs in R&D. The Group posted sales of 47.5 billion Swiss francs. Genentech, United States, is a wholly owned member of the Roche Group. Roche has a majority stake in Chugai Pharmaceutical, Japan. For more information:

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1) E. Perez et al. T-DM1 TDM4450, ESMO 2010, Abstract LBA3
2) Ferlay J, Shin HR, Bray F, Forman D, Mathers C and Parkin DM GLOBOCAN 2008, Cancer Incidence and Mortality Worldwide: IARC Cancer Base No. 10 [Internet]. Lyon, France: International Agency for Research on Cancer; 2010. Available from: