CP-724,714 in Treating Patients With Metastatic Breast Cancer

OBJECTIVES: * Determine the safety and tolerability of CP-724,714 in patients with metastatic HER2-overexpressing breast cancer. * Determine the maximum tolerated dose of this drug in these patients. * Determine, preliminarily, any antitumor activity of this drug in these patients. * Determine the pharmacokinetics of this drug in these patients. * Determine the relationship of drug-related adverse events to pharmacokinetic exposure parameters in these patients. * Determine the relationship of changes in serum HER2 extracellular domain and HER2 receptor tyrosine kinase phosphorylation to pharmacokinetic exposure parameters and clinical outcome in patients treated with this drug. OUTLINE: This is an open-label, dose-escalation, multicenter study. Patients receive oral CP-724,714 on days 1 and 3-21 during course 1 and then daily during subsequent courses. Courses repeat every 3 weeks for up to 1 year in the absence of disease progression or unacceptable toxicity. Cohorts of 3-6 patients receive escalating doses of CP-724,714 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. Patients are followed for at least 30 days. PROJECTED ACCRUAL: A total of 3-20 patients will be accrued for this study within 6 months.