A Study of Trifluridine/Tipiracil (Also Known as S 95005 or TAS-102) in Patients With a Pretreated Colorectal Cancer That Has Spread (Metastatic).

Inclusion Criteria:

* Male or Female participant aged ≥18 years old.
* Has definitive histologically confirmed adenocarcinoma of the colon or rectum.
* Has metastatic lesion(s).
* Has received at least 2 prior regimens of standard chemotherapies (including fluoropyrimidines, irinotecan, oxaliplatin, an anti-VEGF monoclonal antibody and at least one of the anti-EGFR monoclonal antibodies for RAS wild-type patients) for mCRC and is refractory or intolerant to those chemotherapies or is not candidate for those chemotherapies.
* Has Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 during the screening period.
* Is able to take medications orally (i.e., no feeding tube).
* Has adequate organ function.
* Women of childbearing potential must have been tested negative in a serum pregnancy test within 7 days prior to first day of test drug administration. Female participants of childbearing potential and male participants with partners of childbearing potential must agree to use a highly effective method of birth control during the study and for 6 months after the discontinuation of study medication. Women and female partners using hormonal contraceptive must also use a barrier method.

Exclusion Criteria:

* Pregnancy, breastfeeding or possibility of becoming pregnant during the study.
* Eligible for enrolment into another available ongoing clinical study of trifluridine / tipiracil.
* Has previously received trifluridine / tipiracil or hypersensitivity to the active substances or to any of the excipients of trifluridine / tipiracil.
* Has rare hereditary problems of galactose intolerance, the Lapp lactase deficiency, or glucose-galactose malabsorption.
* Has certain serious illness or medical condition(s) described in the protocol.
* Has had certain other recent treatment e.g. major surgery, anticancer therapy, radiation therapy, participation in another interventional study, within the specified time frames prior to first day of study drug administration.
* Has unresolved toxicity of greater than or equal to Common Terminology Criteria for Adverse Events (CTCAE) Grade 2 attributed to any prior therapies (excluding anemia, alopecia, skin pigmentation, and platinum-induced neurotoxicity).