Inclusion Criteria:

          -  Histologically confirmed stage IV colon cancer (American Joint Committee on Cancer
             [AJCC] 7th edition) that has progressed after standard therapy that included
             fluorouracil (5-FU), irinotecan, oxaliplatin, bevacizumab (unless contraindicated) and
             an anti-EGFR antibody, if RAS wild type. Patients who could not tolerate standard
             agents because of unacceptable, but reversible toxicity necessitating their
             discontinuation will be allowed to participate

          -  Patients who had received adjuvant chemotherapy and had recurrence during or within 6
             months of completion of the adjuvant chemotherapy will be allowed to count the
             adjuvant therapy as one chemotherapy regimen

          -  Progression of disease must be documented on the most recent scan

          -  Presence of measurable disease

          -  RAS mutation and mismatch repair deficiency (MMR) status must be determined (or tissue
             availability for testing if not already determined)

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

          -  Life expectancy of at least 3 months

          -  Absolute neutrophil count (ANC) >= 1.5 x 10^9/L

          -  Hemoglobin >= 9 g/dL

          -  Platelets (PLT) >= 75 x 10^9/L

          -  Aspartate aminotransferase (AST)/alanine aminotransferase (ALT) =< 5 x upper limit of
             normal (ULN)

          -  Adequate contraception if applicable

          -  Women who are nursing and discontinue nursing prior to enrollment in the program

          -  Ability to take oral medication (i.e., no feeding tube)

          -  Patient able and willing to comply with study procedures as per protocol

          -  Patient able to understand and willing to sign and date the written voluntary informed
             consent form (ICF) at screening visit prior to any protocol-specific procedures

        Exclusion Criteria:

          -  Patients who have previously received TAS-102

          -  Grade 2 or higher peripheral neuropathy (functional impairment)

          -  Symptomatic central nervous system (CNS) metastases requiring treatment

          -  Other active malignancy within the last 3 years (except for non-melanoma skin cancer
             or a non-invasive/in situ cancer)

          -  Pregnancy or breast feeding

          -  Current therapy with other investigational agents

          -  Active infection with body temperature >= 38 degree Celsius (C) due to infection

          -  Major surgery within prior 4 weeks (the surgical incision should be fully healed prior
             to drug administration)

          -  Any anticancer therapy within prior 3 weeks of first dose of study drug

          -  History of allergic reactions attributed to compounds of similar chemical or biologic
             composition to TAS-102

          -  Current therapy with other investigational agents or participation in another clinical
             study or any investigational agent received within prior 4 weeks

          -  Grade 3 or higher hypersensitivity reaction to oxaliplatin, or grade 1-2
             hypersensitivity reaction to oxaliplatin not controlled with pre-medication

          -  Has unresolved toxicity of greater than or equal to Common Terminology Criteria for
             Adverse (CTCAE) grade 2 attributed to any prior therapies (excluding anemia, alopecia,
             skin pigmentation, and platinum-induced neurotoxicity)