An Investigation of TAS-119 Monotherapy

This is a Phase 1, open-label, non-randomized, dose escalation study of TAS-119 evaluating
the safety, tolerability, PK, pharmacogenomics, pharmacodynamics, and preliminary antitumour
activity in patients with advanced and unresectable solid tumours. The study will evaluate
TAS-119 monotherapy, employing two sequential phases.

- A Dose Escalation Phase

- An Expansion Phase

Inclusion criteria include the following:

1. Is a male or female, ≥ 18 years of age, who has provided written informed consent.

2. Has histologically or cytologically confirmed advanced, unresectable, metastatic solid
tumor(s) for which the patients have no available therapy likely to provide clinical
benefit.

3. Must have an archival FFPE tumor sample available, to be provided to the Sponsor upon
request.

4. In the Expansion Phase: patients should be willing to undergo tumor core biopsy
procedure at pre-treatment and on Day 4, Cycle 1 if, in the judgment of the
investigator, it is considered clinically safe and appropriate to do so. This
requirement is optional but preferred for patients in Dose Escalation.

5. Has adequate organ function.

Women of childbearing potential must have a negative pregnancy test (urine or serum) within
7 days prior to starting the study drug. Both males and females and must agree to use
effective birth control during the study if conception is possible during this interval.

Exclusion:

1. Has received prior treatment with TAS-119.

2. Has received treatment with any proscribed treatments within specified time frames
prior to study drug administration.

3. Has a serious illness or medical condition(s).