*Additional cohort specific criteria may apply

        Inclusion Criteria:

          -  Must be age 18 or older

          -  Ability to provide written informed consent in accordance with federal, local, and
             institutional guidelines

          -  Histological or cytological diagnosis of metastatic cancer or locally advanced cancer
             that is not amenable to local therapy

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

          -  Life Expectancy of at least 3 months

          -  Adequate hepatic, renal (moderately impaired renal function in cohort 1c only),
             cardiac, and hematologic function

          -  Measurable disease by RECISTv1.1 criteria

          -  Resolution of treatment-related toxicities

          -  Willingness to avoid pregnancy or fathering children

          -  Prior anti-PD-1 treatment for combination dose expansion cohorts 1c, 3a - 3d

        Exclusion Criteria:

          -  Currently pregnant or lactating

          -  Unable to receive oral medications

          -  Unable to receive oral or IV hydration

          -  Intolerance to prior anti-PD-1/PD-L1 therapy

          -  Prior anti-PD-1 treatment for combination dose expansion cohorts 1c, 3e - 3h

          -  Prior severe hypersensitivity reaction to another monoclonal antibody (mAb)

          -  Any other current or previous malignancy within 3 years except protocol allowed
             malignancies

          -  Chemotherapy, Tyrosine Kinase Inhibitor therapy, radiation therapy or hormonal therapy
             within 2 weeks

          -  Immunotherapy or biological therapy, or investigational agent within 3 weeks (Note:
             some cohort exceptions allow anti-PD-1 therapy)

          -  Active known or suspected exclusionary autoimmune disease

          -  Any condition requiring systemic treatment with either corticosteroids (> 10 mg daily
             prednisone equivalent) or other systemic immunosuppressive medications within 2 weeks

          -  Concomitant therapy with valproic acid/valproate-containing therapies

          -  Concomitant therapy with allopurinol and other xanthine oxidase inhibitors

          -  History of known risks factors for bowel perforation

          -  Symptomatic ascites or pleural effusion

          -  Major surgery within 28 days before Cycle 1 Day 1

          -  Active infection requiring within 2 weeks prior to first dose of study drug

          -  Patients who have HIV, Hepatitis B or C

          -  Conditions that could interfere with treatment or protocol-related procedures

          -  Active, non-stable brain metastases or CNS disease

          -  Known deficiencies or suspected defect in the urea cycle

          -  Received live-virus vaccination within 30 days (seasonal flu vaccine allowed if
             non-live virus)

          -  NSCLC with EGFR or ALK mutation