Trastuzumab and Erlotinib as First-Line Therapy in Treating Women With Metastatic Breast Cancer Associated With HER2/Neu Overexpression

OBJECTIVES: * Determine the maximum tolerated dose and recommended phase II dose of erlotinib when combined with trastuzumab (Herceptin) as first-line therapy in women with metastatic breast cancer associated with HER2/neu overexpression. (Phase I closed to accrual as of 01/2004) * Determine the safety profile of this regimen in these patients. * Determine the rate and duration of objective response in patients treated with this regimen. * Determine the pharmacologic behavior of this regimen in these patients. * Determine time to disease progression and duration of survival in patients treated with this regimen. * Correlate the antitumor activity of this regimen with epidermal growth factor receptor expression in these patients. OUTLINE: This is a dose-escalation study of erlotinib. (Phase I closed to accrual as of 01/2004). Patients receive oral erlotinib once daily beginning on day 2 and trastuzumab (Herceptin) IV over 30-90 minutes (1-4 hours after erlotinib) once weekly beginning on day 1. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. Cohorts of 3-6 patients receive escalating doses of erlotinib until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 3 or 2 of 6 patients experience dose-limiting toxicity. Once the MTD is determined, additional patients are treated at the recommended phase II dose. Patients are followed every 2 months. PROJECTED ACCRUAL: A total of 3-18 patients will be accrued for the phase I portion (closed to accrual as of 01/2004) and 27-81 patients will be accrued for the phase II portion of this study.