Roche
has said it will submit its new breast cancer drug trastuzumab for regulatory
review in the US and Europe later this year. The decision is based on new Phase III data that showed patients treated with
HER2-positive metastatic breast cancer taking trastuzumab (TDM-1), lived
significantly longer without their disease getting worse.
The drug is seen as a successor to Roche’s ageing HER2+ breast cancer drug
Herceptin (trastuzumab), which made Roche $5.3 billion in sales last
year.
The EMILIA open label trial was studying 991 patients who had been
previously treated with Herceptin and a chemotherapy agent.
The patients taking Roche’s new drug saw a significant increase in
progression-free survival, compared to those who received GSK’s breast cancer
drug Tyverb in combination with Roche’s Xeloda. The overall survival data has not yet been released - this is expected
later this year, along with Roche’s submission for the drug to the EMA and the
FDA.
Hal Barron, chief medical officer of Roche, said: “We are excited about the
EMILIA results because trastuzumab emtansine is our first antibody drug
conjugate, and it may help people who still need more treatment options for
this aggressive disease. “We will work to submit these data to regulatory authorities as quickly as
possible,” he added.
T-DM1 uses a new, targeted antibody that can kill breast cancer cells at a
later stage of the disease after the failure of other chemotherapy and cancer
drugs. It is designed to target and inhibit HER2 signalling and deliver the
chemotherapy directly inside HER2-positive cancer cells. Currently around 25% of breast cancer cases are positive for the HER2
mutation, the protein targeted by Herceptin.
The drug latches on to HER2, interfering with it without killing the cell,
but it must be given with chemotherapy. What T-DM1 does differently is attach trastuzumab and the chemotherapy DM1
together using a stable linker, that is designed to keep trastuzumab emtansine
in one piece until it reaches specific cancer cells.