Inclusion Criteria:

          1. Females or males age ≥ 18 years (at time of signing informed consent)

          2. Histologically confirmed metastatic or recurrent triple-negative breast cancer
             (estrogen receptor (ER) ≤10%; progesterone receptor (PR) ≤10%; HER2 negative by
             immunohistochemistry (IHC) or fluorescent in situ hybridization (FISH)

          3. Part 1: Progressed on at least 1 prior cytotoxic chemotherapy at least 21 days prior
             to the start of study treatment. Part 2: Progressed on no more than 3 prior
             chemotherapy-inclusive regimens for locally advanced or metastatic disease (no limit
             on prior targeted anticancer therapies such as mechanistic target or rapamycin (mTOR)
             or CDK4/6 inhibitors, immune-oncology agents, tyrosine kinase inhibitors, or
             monoclonal antibodies against CTL4 or VEGF) at least 21 days prior to the start of
             study treatment.

          4. Patient is not a candidate for endocrine based therapy or has progressed on at least 2
             prior endocrine based therapies in the locally advanced or metastatic setting

          5. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

          6. Part 2 only: Measurable disease per RECIST version 1.1

        Exclusion Criteria

          1. Documented germline BRCA1 or BRCA2 mutations

          2. Evidence of disease progression during platinum treatment either in the neoadjuvant or
             in the metastatic setting. For patients receiving platinum in the neoadjuvant setting,
             at least 12 months must have elapsed between the last dose of platinum-based treatment
             and enrollment.

          3. Patients with inflammatory breast cancer

          4. Current or anticipated use of medications known to be strong inhibitors or inducers of
             CYP3A4 or substrates of CYP1A2 with narrow therapeutic windows. Strong inhibitors,
             inducers or substrates must be discontinued at least 7 days prior to the first
             administration of study drug.

          5. Current or anticipated use within 7 days prior to the first administration of study
             drug, or during the study, of strong P-gp inhibitors. For a list of strong P-gp
             inhibitors, refer to Section 8.4.1.

          6. Prior anticancer therapy (chemotherapy, radiation, hormone therapy, immunotherapy or
             investigational agent) within 3 weeks from the start of study drug (except for
             nitrosoureas and mitomycin C within 6 weeks from start of study drug).

          7. Have not progressed on prior endocrine therapy and have an ER and/or PR ≥ 1%