Inclusion Criteria:

          -  Histologically or cytologically confirmed HER2-negative locally advanced or metastatic
             (stage IV) breast cancer.

          -  Maximum of one prior line of chemotherapy for advanced or metastatic breast cancer.

          -  Measurable or non-measurable, but radiologically evaluable (except for skin lesions),
             disease according to RECIST 1.1 criteria.

          -  Female aged 18 years or older.

          -  Life expectancy > 3 months.

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

          -  ER-positive disease by local laboratory, determined on most recent available tissue
             (latest biopsy of metastatic lesion, otherwise prior biopsy or surgical specimen).

          -  If previously treated with a taxane in the neoadjuvant or adjuvant setting, the period
             from end of treatment to disease recurrence must have been > 12 months (> 365 days).

          -  Radiation therapy, if given and regardless of site, must be completed at least 2 weeks
             prior to randomization.

          -  Normal hematologic status,

          -  Absolute neutrophil count ≥1000/mm3 (1.0 × 109/L),

          -  Platelets ≥ 100 × 109/L,

          -  Hemoglobin ≥ 9 g/dL (≥ 90 g/L).

          -  Normal renal function: serum creatinine ≤ 1.5 ULN or calculated creatinine clearance ≥
             50 mL/min according to the Cockcroft-Gault formula.

          -  Normal liver function:

          -  Serum total bilirubin ≤ 1.5 × upper limit of normal (ULN). In the case of known
             Gilbert's syndrome, a higher serum total bilirubin (< 3 × ULN) is allowed.

          -  Aspartate transaminase (AST) and Alanine transaminase (ALT) ≤ 3 × ULN; if the patient
             has liver metastases, ALT and AST must be ≤ 5 × ULN.

          -  Women of child bearing potential must have documented negative pregnancy test within 2
             weeks prior to randomization and agree to acceptable birth control (non-hormonal)
             during and up to 6 months after trial therapy.

          -  Written Informed Consent (IC) must be signed and dated by the patient and the
             Investigator prior to starting screening procedures and randomization.

          -  The patient has been informed of and agrees to data transfer and handling, in
             accordance with national data protection guidelines.

        Exclusion Criteria:

          -  More than one prior line of chemotherapy for advanced or metastatic breast cancer

          -  Previous treatment for advanced or metastatic disease with taxanes, or capecitabine or
             vinorelbine or oral cyclophosphamide.

          -  More than 2 lines of previous endocrine therapy for locally advanced or metastatic
             breast cancer.

          -  Known active central nervous system metastases, as indicated by clinical symptoms,
             cerebral edema, and/or progressive growth (patients with history of Central Nervous
             System (CNS) metastases or spinal cord compression are eligible if they are clinically
             and radiologically stable for at least 4 weeks before first dose of trial treatment
             and have not required high-dose steroid treatment in the last 4 weeks).

          -  Peripheral neuropathy grade 2 or higher (CTCAE version 4.0).

          -  Significant uncontrolled cardiac disease (i.e. unstable angina, myocardial infarction
             within prior 6 months), patients classified as having a New York Heart Association
             (NYHA) class III or IV congestive heart failure.

          -  Pregnant or lactating.

          -  Prior history of non-breast malignancy (except for adequately controlled basal cell
             carcinoma of the skin, carcinoma in situ of the cervix, in situ carcinoma of the
             bladder).

          -  Any concurrent condition which in the Investigator's opinion makes it inappropriate
             for the patient to participate in the trial or which would jeopardize compliance with
             the protocol.

          -  Contraindications or known hypersensitivity to the trial medication or excipients.

          -  The use of any anti-cancer investigational agents within 30 days prior to expected
             start of trial treatment.