T-DMI, a combination of trastuzumab (Herceptin) and a cell-killing agent developed by ImmunoGen, has demonstrated superior progression-free survival when compared to just Herceptin and chemotherapy. A Phase II trial with 137 patients with HER2-positive metastatic breast cancer focused on T-DMI as the initial breast cancer treatment.

Progression-free survival, also known as PFS is used to describe how long a disease (usually cancer) does not get worse while the patient is on a medication; it is also used to measure the period after the medication is stopped.

T-DM1 used to be known as trastuzumab-DM1. Trastuzumab was developed by Genentech, which belongs to pharmaceutical giant Roche.

Roche says details of its findings will be submitted for presentation at a future conference. Last year, favorable preliminary data on T-DM1 was reported, showing encouraging results in tumor shrinkage in patients with a minimum of 4 months of follow-up, but without details on progression-free survival. Side-effects were also much less when compared to conventional chemotherapy.

Daniel Junius, President and CEO of ImmunoGen, said:

“This top-line information about T-DM1’s performance in the first-line setting is very encouraging and adds to the favorable efficacy and safety data reported across a number of T-DM1 studies. We look forward to learning the detailed data when they are reported at a medical conference.”

Trastuzumab emtansine uses Imunogen’s TAP (Targeted Antibody Payload) technology along with the trastuzumab antibody. This is a global development collaboration agreement between Roche (Genentech) and ImmunoGen.

It is undergoing Phase III trials for second-line and first-line treatment of HER2-positive metastatic breast cancer. A Phase II trial comparing safety of T-DM1 started in 2010.

Hal Barron, M.D., Chief Medical Officer and Head of Global Development, Roche, said:

“These encouraging data support our ongoing development program for trastuzumab emtansine (T-DM1) in first-line HER2-positive metastatic breast cancer. 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.”

Breast cancer is the most common female cancer globally. There are approximately 1.4 million new breast cancer diagnoses each year worldwide. Over 450,000 people with breast cancer die from the disease yearly.

Between 15% and 25% of women with breast cancer have the HER2-positive type. Sources: Roche, ImmunoGen

Written by Christian Nordqvist