Inclusion Criteria:

   1. Subjects with pathologically confirmed colorectal carcinoma that is metastatic or
   unresectable and which is refractory to standard therapy. To be considered refractory,
   a subject must have experienced progression (or intolerance) after treatment with
   standard approved regimens including, oxaliplatin, irinotecan flouropyrimidine,
   bevacizumab, and cetuximab or panitumumab if KRAS wildtype.

   2. Subjects will not be treated with any radiation, chemotherapy, or investigational
   agents while enrolled in this protocol.

   3. Eastern Cooperative Oncology Group (ECOG) performance status 0,1, or 2.

   4. At least 2 weeks since the last previous cancer treatment including: chemotherapy,
   radiation therapy, immunotherapy, surgery, hormonal therapy, or targeted biologics.

   5. Age ≥ 18 years, male or female subjects.

   6. Serum potassium and magnesium levels within institutional normal limits. Total serum
   calcium or ionized calcium level must be greater than or equal to the lower limit of
   normal.

   7. Adequate renal function, defined by serum creatinine ≤ 1.5 x ULN.

   8. Adequate hepatic function

   9. Adequate bone marrow function

10. For women of childbearing potential (WOCBP), a negative serum pregnancy test result at
   Screening.

11. Signed and dated institutional review board (IRB)-approved informed consent before any
   protocol-specific screening procedures are performed.

12. Patients enrolled must, in the Investigator's judgment, be healthy enough to stay on
   the clinical trial for three months.

Exclusion Criteria:

   1. Mechanical obstruction that would prevent adequate oral nutritional intake.

   2. Serious uncontrolled medical disorder, or active infection, that would impair the
   ability of the patient to receive protocol therapy.

   3. Uncontrolled or significant cardiovascular disease, including:

   4. Dementia or altered mental status that would prohibit the understanding or rendering
   of informed consent.

   5. Subjects who have not recovered from the adverse effects of prior therapy at the time
   of enrollment to ≤ grade 1; excluding alopecia and grade 2 neuropathy.

   6. Immunocompromised subjects, including subjects known to be infected with human
   immunodeficiency virus (HIV).

   7. Known hepatitis B surface antigen and/or positive hepatitis C antibody and presence of
   hepatitis C RNA.

   8. History of tuberculosis (latent or active) or positive Interferon-gamma release assay
   (IGRA).

   9. Receipt of a live (attenuated) vaccine within 1 month prior to Screening

10. Subjects with history of hypersensitivity to compounds of similar chemical or biologic
   composition of XILONIX™.

11. Women who are pregnant or breastfeeding.

12. WOCBP or men whose sexual partners are WOCBP who are unwilling or unable to use an
   acceptable method of contraception for at least 1 month prior to study entry, for the
   duration of the study, and for at least 3 months after the last dose of study
   medication.

13. Weight loss >20% in the previous 6 months.