The purpose of this study is to compare the pharmacokinetics of trifluorothymidine (FTD) as a component of TAS-102 with FTD alone.

This is a Phase 1, open-label, randomized, parallel, 2-group study evaluating the PK of FTD as a TAS-102 component compared with FTD alone in patients with advanced solid tumors (excluding breast cancer). Patients will be randomized to receive a single dose of TAS-102 or FTD during the PK contribution phase and will receive continuing cycles of TAS-102 during the extension phase.

Inclusion Criteria:

1. Has provided written informed consent
2. Has advanced solid tumors (excluding breast cancer) for which no standard therapy exists
3. ECOG performance status of 0 or 1
4. Is able to take medications orally
5. Has adequate organ function (bone marrow, kidney and liver)
6. Women of childbearing potential must have a negative pregnancy test and must agree to adequate birth control if conception is possible. Males must agree to adequate birth control.

Exclusion Criteria:

1. Has had certain other recent treatment e.g. anticancer therapy, received investigational agent, within the specified time frames prior to study drug administration
2. Certain serious illnesses or medical condition(s)
3. Has had either partial or total gastrectomy
4. Has unresolved toxicity of greater than or equal to CTCAE Grade 2 attributed to any prior therapies
5. Known sensitivity to TAS-102 or its components
6. Is a pregnant or lactating female
7. Refuses to use an adequate means of contraception (including male patients)