Key Inclusion Criteria:

          -  Pathologically confirmed advanced solid tumor for which standard therapy proven to
             provide clinical benefit does not exist or is no longer effective.

          -  Eastern Collaborative Oncology Group (ECOG) Performance Status of 0-1.

          -  Progressive disease, either measurable on physical examination or imaging by Response
             Evaluation Criteria in Solid Tumors (RECIST v1.1) or PCWG3 or by informative tumor
             marker(s).

          -  Adequate organ function based on laboratory values.

          -  If there is a known history of brain metastases, either treated or untreated, the
             disease must be stable.

          -  Willing and able to provide written Informed Consent and comply with the requirements
             of the study.

        Key Exclusion Criteria:

          -  Any cytotoxic chemotherapy within 21 days prior to initiation of study drug.

          -  Any immunomodulatory drug therapy, anti-neoplastic hormonal therapy, immunosuppressive
             therapy, corticosteroids, or growth factor treatment within 14 days prior to
             initiation of study drug.

          -  Presence of an acute or chronic toxicity of prior chemotherapy, that has not resolved
             to ≤Grade 1, as determined by CTCAE v 4.0.

          -  Receipt of more than 3 prior regimens of cytotoxic chemotherapy for metastatic
             disease.

          -  Bone marrow reserve which is not adequate for participation in this trial.

          -  Radiotherapy within 28 days prior to baseline.

          -  Fraction of radiotherapy to >25 % of bone marrow.

          -  Major surgery within 28 days prior to initiation of study drug.

          -  Active bacterial, viral, or fungal infection requiring systemic therapy.

          -  Known human immunodeficiency virus or acquired immunodeficiency syndrome related
             illness.

          -  Clinically significant hearing impairment, as judged by the Principal Investigator.

          -  Uncontrolled cardiovascular abnormalities.

          -  Previous malignancy, except for non-squamous-cell carcinoma of skin or carcinoma
             in-situ of the uterine cervix, unless the tumor was treated with curative intent more
             than 2 years prior to study entry.