Paclitaxel and Bavituximab in Treating Patients With HER2-Negative Metastatic Breast Cancer

PRIMARY OBJECTIVES: I. To determine the safety, feasibility, and tolerability of combining paclitaxel with weekly bavituximab therapy. SECONDARY OBJECTIVES: I. To describe changes in pharmacodynamic markers and coagulation markers in response to single agent and combined therapy. OUTLINE: Patients receive paclitaxel intravenously (IV) on days 1, 8, and 15 and bavituximab IV on days 1, 8, 15, and 22 (days 15 and 22 only of course 1). Courses repeat every 4 weeks in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up periodically.