To evaluate the pharmacokinetics, mass balance recovery, metabolite profile and metabolite identification of [14C]TAS-303 following oral single dose

Inclusion Criteria:

1. Healthy adult male subjects who provided written informed consent to participate in the study
2. Aged 18 years or older and younger than 40 years at the time of informed consent
3. Capable of oral intake.
4. Body weight of 50 kg or more and body mass index of 18.5 or more and less than 25.0
5. Had blood pressure, pulse rate, and body temperature meeting any of the following at screening:

Systolic blood pressure: ≧90 mmHg and ≦139 mmHg, Diastolic blood pressure: ≧40 mmHg and ≦89 mmHg, Pulse rate: ≧40 beats per minute (bpm) and ≦99 bpm, Body temperature: ≧35.0°C and ≦37.4°C

Exclusion Criteria:

1. Had current or previous hypersensitivity or allergy to drugs

2. Had current or previous drug abuse (including use of illicit drugs) or alcoholism

3. Had any concurrent disease (including symptoms and signs; however, diseases that do not affect evaluations in the study such as asymptomatic pollinosis and wart are excluded)

4. Received a radioisotope-labeled substance or subject to a large quantity of radiation exposure* within 12 months before the first dose of TAS-303.

   * A large quantity of radiation exposure includes continuous X-ray irradiation, computed tomography (CT) scan, gastric barium test, and positron emission tomography (PET) scan, excluding tests with low radiation exposure (e.g., chest, bone, or dental X-ray examination, or X-ray examination before boarding an airplane).

5. Occupationally exposed to radiation within a year before the first dose of TAS-303 (such as operators who are involved in nuclear power or radiation operations).

Data will not be shared according to the Sponsor policy on data sharing. Taiho policy on data sharing may be found at https://www.taiho.co.jp/en/science/policy/clinical\_trial\_information\_disclosure\_policy/index.html.