GW572016 With Docetaxel and Trastuzumab for the Treatment Of Untreated ErbB2 Over-Expressing Metastatic Breast Cancer

Inclusion Criteria: * Subjects must be 18 years of age. Criteria for female subjects: * Non-child-bearing potential (i.e., women with functioning ovaries who have a current documented tubal ligation or hysterectomy, or women who are post- menopausal); * Child-bearing potential (i.e., women with functioning ovaries and no documented impairment of oviductal or uterine function that would cause sterility.) This category includes women with oligomenorrhoea (severe), women who are perimenopausal, and young women who have begun to menstruate. These subjects must have a negative serum pregnancy test at screening and agree to one of the following: * Complete abstinence from intercourse from 2 weeks prior to administration of the first dose of study medication until 28 days after the final dose of study medication; or * Consistent and correct use of one of the following acceptable methods of birth control: * male partner who is sterile prior to the female subject's entry into the study and is the sole sexual partner for that female subject; implants of levonorgestrel; injectable progestogen; any intrauterine device (IUD) with a documented failure rate of less than 1% per year; oral contraceptives (either combined or progestogen only); or barrier methods, including diaphragm or condom with a spermicide. * Subjects must have an ECOG Performance Status of 0 to 1. * Subjects must have histologically- or cytologically-confirmed invasive breast cancer with Stage IV disease. * Subjects mu…