Vorinostat and Trastuzumab in Treating Patients With Metastatic or Locally Recurrent Breast Cancer

This phase I/II trial is studying the side effects and best dose of vorinostat when given together with trastuzumab and to see how well they work in treating patients with metastatic breast canceror breast cancer that has recurred in the chest wall. Vorinostat may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Monoclonal antibodies, such as trastuzumab, can block tumor growth in different ways. Some find tumor cells and kill them or carry tumor-killing substances to them. Others interfere with the ability of tumor cells to grow and spread. Vorinostat and trastuzumab also may stop the growth of tumor cells by blocking blood flow to the tumor. Giving vorinostat together with trastuzumab may be a better way to block tumor growth.

PRIMARY OBJECTIVES: I. To determine the maximum tolerated dose of vorinostat in combination with trastuzumab (Herceptin) in patients with metastatic or local chest wall recurrent HER-2-amplified breast cancer. (Phase I) II. To determine the toxic effects of this regimen in these patients. (Phase I) III. To determine the response rate in patients treated with this regimen. (Phase II) SECONDARY OBJECTIVE: I. To determine the time to progression in patients treated with this regimen. (Phase II) OUTLINE: This is an open-label, multicenter, dose-escalation study of vorinostat. PHASE I: Patients receive oral vorinostat twice daily on days 1-14 and trastuzumab (Herceptin®) IV over 90 minutes on day 1. Courses repeat every 21 days in the absence of disease progression or unacceptable toxicity. Cohorts of 3-6 patients receive escalating doses of vorinostat 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. At least 6 patients are treated at the MTD. PHASE II: Patients receive vorinostat at the MTD and trastuzumab as in phase I. After completion of study treatment, patients are followed periodically for 3 years.