Inclusion Criteria:

          -  Histologically or cytologically confirmed HER2-negative adenocarcinoma of the breast

          -  Locally advanced (Stage 3B) or metastatic (Stage 4) disease

          -  Eastern Cooperative Oncology Group (ECOG) performance status 0 to 2

          -  Received up to 2 prior chemotherapy regimens (not including neoadjuvant/adjuvant
             therapy) for advanced or metastatic disease

          -  Participants with hormone-receptor positive tumors must have failed available lines of
             hormonal therapy unless hormone therapy was not tolerated or not clinically
             appropriate

          -  ≥ 2 weeks elapsed from the completion of previous treatment regimen and must have
             recovered or be at a new stable baseline from any related toxicities

          -  Radiographically measurable or evaluable disease

          -  An mGPS of 1 or 2 as defined below:

               -  Criteria:

                    1. modified Glasgow prognostic score (mGPS) of 1: CRP > 10 mg/L and albumin ≥
                       35 g/L

                    2. mGPS of 2: C-reactive protein (CRP) > 10 mg/L and albumin < 35 g/L

        Exclusion Criteria:

          -  Received prior treatment with capecitabine or fluoropyrimidine for advanced or
             metastatic disease

          -  Received more than 2 prior regimens for advanced or metastatic disease (not including
             hormonal therapy in the metastatic setting or neoadjuvant or adjuvant therapies)

          -  Unknown hormone-receptor status

          -  Ongoing radiation therapy or radiation therapy administered within 2 weeks of
             enrollment

          -  Concurrent anticancer therapy

          -  Inadequate renal, hepatic or bone marrow function

          -  Another current or previous malignancy within 2 years of study entry unless approved
             by the sponsor