Inclusion Criteria

Inclusion criteria:

- Histologically documented breast cancer (either primary or metastatic site) that is:

- ER (Estrogen Receptor)- negative, PR (Progesterone Receptor)-negative (for ER-
and PR-negative: <10% tumor staining by immunohistochemistry [IHC]) AND

- Human Epidermal Growth Factor 2 (HER2) non-overexpressing by IHC (0,1+) or, IHC
2+ and Fluorescence In Situ Hybridization (FISH negative). Patients IHC 3+ are
not eligible;

- Metastatic breast cancer with measurable disease by the revised guideline for
Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1 criteria);

- Prior treatment that includes:

- never having received anticancer therapy for metastatic disease OR

- having received 1 or 2 prior chemotherapy regimens in the metastatic setting
(prior neo-adjuvant/adjuvant systemic therapy is considered as a prior
chemotherapy if the first relapse occurred less than one year after the last
treatment administration);

Exclusion criteria:

- Prior treatment with gemcitabine, carboplatin, cisplatin or any PARP inhibitor;

- Bone metastasis as only disease location (except for bone metastasis with measurable
soft tissue component);

- Major medical conditions that might affect study participation e.g., uncontrolled
pulmonary, renal, or hepatic dysfunction, uncontrolled infection, cardiac disease.

The above information is not intended to contain all considerations relevant to a
patient's potential participation in a clinical trial.