The study showed that the risks of the disease worsening or death of a patient taking their drug (T-DM1), was reduced by 35%, when compared with those on apatinib plus Xeloda® (capecitabine) chemotherapy (HR=0.65, p<0.0001).
There were also indications in the trial that patients would generally live longer, but obviously more time is needed to fully mature the data of the subject patients. Roche did announce the one year survival rate to be nearly 85% and the two year rate to be 65%, which is a marked improvement from lapatinib plus Xeloda that comes in at only 77% and 47.5% for one and two years respectively.
Side effects from trastuzumab emtansine were also seen to be less, with fewer people on the drug experiencing a grade three or higher (meaning severe) reaction. Those on lapatinib plus Xeloda had a 57% reaction rate, compared to little over 40% for trastuzumab emtansine. The time-to-symptom progression, a patient-reported measure of quality of life, was also improved in people who received trastuzumab emtansine: 7.1 months in people who received trastuzumab emtansine compared to 4.6 months in people who received lapatinib plus Xeloda.
The EMILIA study is the first randomized Phase III trial of trastuzumab emtansine in people with HER2-positive mBC who had previously received Herceptin® (trastuzumab) and a taxane chemotherapy.
The results of the EMILIA data will be presented during the plenary session at the 48th Annual Meeting of the American Society of Clinical Oncology (ASCO) in Chicago by Kim Blackwell, M.D., Duke University School of Medicine (Abstract LBA1, Sunday, June 3, 1:45 p.m. CDT). The EMILIA data were also featured in the official ASCO press program on Saturday, June 2.
Hal Barron, M.D., chief medical officer and head, Global Product Development said that:
"The encouraging efficacy, safety profile and quality of life results from the EMILIA study support our belief that trastuzumab emtansine may have an important role for patients with HER2-positive metastatic breast cancer ... We are working with global regulatory authorities to submit these data as quickly as possible and hope that trastuzumab emtansine will soon be available to patients with this aggressive type of breast cancer."
Genentech and Roche say they plan to submit applications for trastuzumab emtansine in HER2-positive mBC this year to the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA). Trastuzumab emtansine is an investigational medicine. What the drug does is basically attach the antibody trastuzumab to a chemotherapy DM1, using a stable linker. Thus, the medicine is delivered inside the cell cancer cells.