Inclusion Criteria:

          -  Part 1: Have documented incurable/locally advanced or metastatic solid tumors that
             have either relapsed or are refractory or intolerant to the standard therapies of
             proven clinical benefit.

          -  Part 2: Availability of archival tumor tissue block or slides (Fresh tumor biopsy will
             be required if archival tissue is not available)

          -  Part 2, Cohort 1: Incurable/locally advanced or metastatic KRAS-mutant CRC previously
             treated with systemic therapy (examples include: oxaliplatin-, irinotecan-and 5
             FU-based chemotherapy (unless contraindicated) with or without bevacizumab)

          -  Part 2, Cohort 2: Incurable/locally advanced or metastatic KRAS-mutant NSCLC
             previously treated with systemic chemotherapy including platinum-based and
             anti-PD-1/PDL-1 therapy (unless contraindicated)

          -  Part 2, Cohort 3: Advance KRAS-mutant Pancreatic Ductal Adenocarcinoma (PDAC)
             harboring a mutation or loss in CDKN2A (PDAC) and received treatment with one or more
             lines of systemic chemotherapy with FOLFIRINOX and/or gemcitabine/abraxane in the
             neoadjuvant, adjuvant, or metastatic disease setting or unable to receive standard of
             care chemotherapy

        Cohort 4 may be opened only if Cohort 3 achieves predefined criteria for efficacy

        -Part 2 Cohort 4: Advanced KRAS-mutant Pancreatic Ductal Adenocarcinoma (PDAC). ·
        Histological or cytological diagnosis of advanced or metastatic KRAS-mutant with CDKN2A
        wild type (PDAC) and received treatment with one or more lines of systemic chemotherapy
        with FOLFIRINOX and/or gemcitabine/abraxane in the neoadjuvant, adjuvant, or metastatic
        disease setting or unable to receive standard of care chemotherapy.

        For both Part 1 and 2:

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

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

          -  PER RECIST v1.1 evaluable disease (for part 1) or measurable disease (for Part 2)

          -  Recovery to baseline or to Grade 1 CTCAE v5.0 of toxicities that were related to prior
             therapies

        Exclusion Criteria:

          -  Prior treatment with CB-839 or palbociclib

          -  Unable to receive oral medication

          -  Infection requiring more than 5 days of parenteral antibiotics, antivirals, or
             antifungals within two weeks prior to C1D1

          -  Unable to discontinue proton pump inhibitor use before study treatment

          -  Refractory nausea and vomiting, uncontrolled diarrhea, malabsorption, significant
             small bowel resection or gastric bypass surgery, use of feeding tubes or other
             situation that may preclude adequate absorption

          -  Active and/or untreated central nervous system metastasis. Patients with treated brain
             metastasis must have (1) documented radiographic stability of at least 4 weeks in
             duration demonstrating on baseline central nervous system imaging prior to study
             treatment and (2) be symptomatically stable and off steroids for at least 2 weeks
             before administration of any study treatment.

          -  Major surgery within 28 days prior to first dose of study drug

          -  Receipt of any anticancer therapy within the following windows:

               1. small molecule TKI therapy (including investigational) within 2 weeks or 5
                  half-lives prior to expected Cycle 1 Day 1 dose

               2. any type of anti-cancer antibody or cytotoxic chemo within 4 weeks prior to Cycle
                  1 Day 1 Dose

               3. radiation therapy for bone metastasis within 2 weeks prior or any other external
                  radiation therapy within 4 weeks prior to C1D1

               4. patients with clinically relevant ongoing complications from prior radiation
                  therapy are not eligible