Cyclophosphamide and Veliparib in Treating Patients With Locally Advanced or Metastatic Breast Cancer

Inclusion Criteria: * Phase I: Patients must have histologically confirmed breast cancer (metastatic breast cancer \[MBC\]) that is human epidermal growth factor receptor 2 (HER2/neu) negative (as determined by local pathology or reference laboratory), and have disease that is metastatic (stage IV \[TxNxM1\]) or locally advanced and not amenable to potentially curative surgical resection (eg, clinical stage IIIB-C) * HER2/neu negative disease (performed on primary tumor and/or metastatic lesion using commercially available/approved assay in local institutional or reference laboratory), according to American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines * National Comprehensive Cancer Network (NCCN) guidelines recommend for metastatic breast cancer "…biopsy documentation of first recurrence, if possible, and determination of hormone receptor status (estrogen receptor \[ER\] and progesterone receptor \[PR\]) and HER2 status…."; therefore, histologic and/or cytologic confirmation of metastatic disease is encouraged whenever feasible, but not required; in some circumstances, histologic confirmation may not be feasible (eg, bone metastases not amenable to biopsy and elevated cancer antigen \[CA\]27-29 tumor marker); for patients who have had histologic confirmation of metastatic disease, it is required that the biopsy confirm that the metastatic tumor is ER and/or PR positive, and HER2/neu negative; for patients in whom biopsy confirmation …