EDMONTON, Canada-Two docetaxel (Taxotere)-based
chemotherapy regimens in combination with the monoclonal antibody trastuzumab
(Herceptin) given after surgery significantly improved disease-free survival
(DFS) in women with early-stage HER2-positive breast cancer, according to
interim results of a phase III trial announced by the Breast Cancer
International Research Group (BCIRG) and Sanofi-Aventis. The BCIRG 006 trial
compared a standard treatment arm of four cycles of doxorubicin (Adriamycin)
and cyclophosphamide followed by docetaxel (AC-T) with two trastuzumab-containing
regimens: AC-T plus trastuzumab (AC-TH) and docetaxel plus carboplatin plus 1
year of trastuzumab (TCH) given concomitantly with chemotherapy.
The study, which enrolled 3,222 women, was sponsored by
Sanofi-Aventis and partially supported by Genentech. The study's Independent
Data Monitoring Committee reviewed findings from the trial, including cardiac
safety data and the first interim efficacy analysis based on 322 events, and
agreed to release the data, as efficacy boundaries have been crossed for the
two investigational arms.
After 23 months of follow-up, the relative reduction in the
risk of relapse was 51% and 39%, respectively, for the
AC-TH and TCH arms, compared with the AC-T control arm. Cardiac safety data
(cut-off December 31, 2004) showed the following proportion of protocol-defined
cardiac events: 1.2%, 2.3%, and 1.2% for AC-T, AC-TH, and TCH, respectively.
The BCIRG plans to present full interim efficacy and safety
results, as well as updated cardiac analyses, during the San Antonio Breast
Cancer Symposium in December 2005.