An Open-Label, Expanded Access Protocol of Iniparib Breast Cancer

Inclusion Criteria: * Histologically documented breast cancer (either primary or metastatic site) that is ER-negative, PR-negative, and HER2 non-over expressing by immunohistochemistry (0, 1) or in situ hybridization (ISH) including; fluorescence (FISH) in situ hybridization / chromogenic in situ hybridization (CISH) with a ratio \< 2.0 * One to three prior chemotherapy regimens in the metastatic setting. Prior adjuvant/neoadjuvant therapy is allowed. Prior Gemcitabine and/or Platinum agents are allowed. * Metastatic breast cancer (Stage IV) * Female, ≥18 years of age * Eastern Cooperative Oncology Group (ECOG) performance status of 0 - 1 * Organ and marrow function as follows: absolute neutrophil count (ANC) ≥1500/mm3, platelets ≥100,000/dL, hemoglobin ≥9 g/dL, bilirubin ≤1.5 mg/dL, serum creatinine ≤1.5 mg/dL or creatinine clearance ≥60 mL/min, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤2.5 times the upper limit of normal if no liver involvement or ≤5 times the upper limit of normal with liver involvement * For women of child bearing potential, documented negative pregnancy test within two weeks of EAP entry and agreement to acceptable birth control during the duration of the EAP therapy * Capability to understand and comply with the protocol and signed informed consent document Exclusion Criteria: * Systemic anticancer therapy within 14 days of the first dose of study drug * Has not recovered to grade ≤1 from adverse events (AEs) per National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) v3.0, with the exception of alopecia, related to anticancer therapy prior to the first dose of study drug * Major medical conditions that might affect EAP participation (e.g. uncontrolled pulmonary, renal, or hepatic dysfunction, uncontrolled infection, cardiac disease) * Brain metastases requiring steroids or expected to require other therapeutic intervention during study participation, including WBRT and intrathecal therapy. Patients must be \> 21-days from neurosurgical intervention * Pregnant or breastfeeding * Inability or unwillingness to abide by the EAP protocol or cooperate fully with the investigator or designee Enrollment is limited and will be determined by a validated Random-Selection Process administered by NORD (National Organization of Rare Disorders).