Gefitinib, Trastuzumab, and Docetaxel in Treating Patients With Metastatic Breast Cancer

RATIONALE: Gefitinib may stop the growth of tumor cells by blocking the enzymes necessary for their growth. Monoclonal antibodies such as trastuzumab can locate tumor cells and either kill them or deliver tumor-killing substances to them without harming normal cells. Drugs used in chemotherapy, such as docetaxel, work in different ways to stop tumor cells from dividing so they stop growing or die. Combining gefitinib and trastuzumab with docetaxel may kill more tumor cells. PURPOSE: This phase I/II trial is studying the best dose of docetaxel when given together with gefitinib and trastuzumab in treating patients with metastatic breast cancer.

OBJECTIVES: Primary * Determine the safety and efficacy of gefitinib, trastuzumab (Herceptin®), and docetaxel, in terms of time to disease progression, in patients with HER2/neu-overexpressing metastatic adenocarcinoma of the breast. Secondary * Determine the objective tumor response rate in patients treated with this regimen. * Correlate expression and/or degree of phosphorylation of epidermal growth factor receptor, HER2/neu, c-fos, Akt, ERK½, P13K, p53, p21, and p27 with outcome in patients treated with this regimen. OUTLINE: This is a phase I, multicenter, dose-escalation study of docetaxel followed by a phase II study. Patients are stratified according to trastuzumab (Herceptin®)-naive vs trastuzumab-failure. * Phase I: Patients receive oral gefitinib once daily on days 2-14. Patients also receive trastuzumab\* IV over 30-90 minutes and docetaxel IV over 1 hour on day 1. Courses repeat every 21 days in the absence of disease progression or unacceptable toxicity. NOTE: \*Trastuzumab is given at a higher dose (loading dose) in course 1 and then at a lower dose in subsequent courses. Cohorts of 3-6 patients receive docetaxel at dose level 1. If no dose-limiting toxicity (DLT) is observed in the first cohort of 3 patients, the dose of docetaxel remains the same. If 1 DLT is observed in the first cohort of 3 patients, 3 additional patients are added (for a total of 6 patients) to dose level 1. If no further DLTs are observed at dose level 1, the dose of docetaxel remains the same. If 2 of 3 or 2 of 6 patients experience DLT at dose level 1, the dose of docetaxel is considered above the maximum tolerated dose (MTD) and is subsequently reduced. If 2 of 3 or 2 of 6 patients experience DLT at the reduced dose of docetaxel, the study is stopped. * Phase II: Patients receive docetaxel at the MTD and gefitinib and trastuzumab as in phase I. Patients are followed for survival. PROJECTED ACCRUAL: A total of 3-76 patients will be accrued for this study within 26 months.