['colon adenocarcinoma', 'rectal adenocarcinoma', 'recurrent colon carcinoma', 'recurrent rectal carcinoma', 'stage iva colon cancer', 'stage iva rectal cancer', 'stage ivb colon cancer', 'stage ivb rectal cancer']
['capecitabine', 'nintedanib']

        Inclusion Criteria:

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

          -  Hemoglobin >= 9 g/dL

          -  Absolute neutrophil count >= 1500/mm^3

          -  Platelet count >= 100,000/mm^3

          -  Creatinine =< 1.5 upper limit of normal (ULN) AND creatinine clearance (CrCl) > 50
             mL/min by Cockcroft-Gault equation

          -  Males = (140 -age (yrs) (body weight (kg)/(72) (serum creatinine) (mg/dL)

          -  Females = 0.85 * (140-age (yrs) (body weight (kg)/(72)(serum creatinine (mg/dL)

          -  Bilirubin < ULN

          -  Aspartate aminotransferase (AST)/alanine aminotransferase (ALT) =< 1.5 ULN if without
             liver metastases

          -  AST/ALT =< 2.5 x ULN if with liver metastases

          -  Coagulation parameters: international normalized ratio (INR) =< 2, prothrombin time
             (PT) and partial thromboplastin time (PTT) < 1.5 X institutional ULN

          -  Have measurable disease per RECIST 1.1 criteria

          -  Histologically or cytologically proven adenocarcinoma of the colon or rectum

          -  Prior progression following a fluoropyrimidine-based therapy and progression following
             or intolerance to irinotecan and oxaliplatin, as well as anti-epidermal growth factor
             receptor (EGFR) therapy (e.g., panitumumab or cetuximab) for rat sarcoma viral
             oncogene homolog (RAS) wild-type patients

          -  Ability to swallow and retain oral medication

          -  Participants of child-bearing potential must agree to use adequate contraceptive
             methods (e.g., hormonal or barrier method of birth control; abstinence) prior to study
             entry and for three months following completion of therapy; should a woman become
             pregnant or suspect she is pregnant while she or her partner is participating in this
             study, she should inform her treating physician immediately

          -  Participant or legal representative must understand the investigational nature of this
             study and sign an Independent Ethics Committee/Institutional Review Board approved
             written informed consent form prior to receiving any study related procedure

        Exclusion Criteria:

          -  Prior treatment with nintedanib

          -  Prior treatment with regorafenib

          -  Major injuries or surgery within the 4 weeks prior to initiation of therapy with
             incomplete wound healing or planned surgery during the on-study treatment period

          -  Uncontrolled hypertension: systolic blood pressure >= 160, diastolic blood pressure >=
             90

          -  Urine protein/creatinine ratio >= 1.0

          -  History of clinically significant hemorrhagic or thrombotic event within the past 6
             months, not including uncomplicated catheter-associated venous thrombosis; patients on
             anti-coagulation are not permitted to be on any oral formulations (warfarin,
             rivaroxaban, dabigatran, etc.) due to concern for drug-drug interaction

          -  Unstable angina, symptomatic congestive heart failure or cardiac arrhythmia requiring
             anti-arrhythmic therapy (beta-blockers, calcium channel blockers and digoxin are
             allowed)

          -  History of cerebrovascular or myocardial ischemia within 6 months of initiation

          -  Known inherited predisposition to bleeding or thrombosis

          -  Known active or chronic hepatitis B or C or human immunodeficiency virus (HIV)

          -  Untreated brain metastases

          -  History of second primary malignancy diagnosed within 3 years prior to enrollment,
             excluding:

               -  In-situ cervical carcinoma

               -  Superficial bladder cancer

               -  Non-melanoma skin cancer

               -  Stage I breast cancer

               -  Low grade (Gleason =< 6) localized prostate cancer

               -  Any additional malignancy which has been in clinical remission for at least 1
                  year

          -  Pregnant or nursing female participants

          -  Unwilling or unable to follow protocol requirements

          -  Any condition which in the Investigator's opinion deems the participant an unsuitable
             candidate to receive study drug

          -  Received an investigational agent within 4 weeks prior to enrollment

          -  PHASE I: History of intolerance to capecitabine at doses =< 1000 mg/m^2 BID, as
             defined by documented >= grade 3 hand-foot syndrome, documented severe diarrhea
             requiring hospitalization, or other documented severe adverse events (AEs)
             attributable to capecitabine

          -  PHASE II: History of intolerance to capecitabine at doses below 1000 mg/m^2 BID, as
             defined by documented >= grade 3 hand-foot syndrome; documented severe diarrhea
             requiring hospitalization; or other documented severe AEs attributable to capecitabine
      