A Study to Assess Absolute Bioavailability (ABA) of TAK-831 and to Characterize Mass Balance, Pharmacokinetics (PK), Metabolism, and Excretion of [14C]TAK-831 in Male Healthy Participants

The drug being tested in this study is called TAK-831 (also known as luvadaxistat). The study will determine ABA in Period 1, and the absorption, metabolism, excretion, and mass balance of TAK-831 after single oral administration in Period 2 in healthy adult male participants, by collecting plasma, urine, and feces samples for drug concentration analysis, and plasma, whole blood, urine, and fecal samples for total radioactivity analysis and metabolic profiling.

The study will enroll approximately 6 participants. The study is designed to consist of 2 periods: Period 1 (ABA study period) and Period 2 (absorption, distribution, metabolism, and elimination [ADME] study period). In Period 1 (ABA study period), all participants will receive a single unlabelled oral dose of TAK-831 as tablet and a microdose intravenous infusion of 50 μg (approximately 1 μCi) [14C]TAK-831, followed by a washout period of 8 days before the dose in Period 2. In Period 2 (ADME study period), all participants will receive a single dose of 500 mg (approximately 100 μCi) [14C]TAK-831 as an oral suspension.

This single center trial will be conducted in the United States. The overall time to participate in this study is approximately 65 days including screening period. Participants will be contacted approximately 30 days after the last dose of study drug for a follow-up assessment.

Inclusion criteria

• Weighs at least 45 kilogram (kg) and body mass index (BMI) greater than or equal to (>=) 18.0 and less than (˂) 32.0 kilogram per square meter (kg/m^2) at screening.

Exclusion criteria

• Seated blood pressure is less than 90/40 millimeter of mercury (mmHg) or greater than 140/90 mmHg at screening.
• Seated heart rate is lower than 40 beats per minute (bpm) or higher than 99 bpm at screening.
• Estimated creatinine clearance <80 milliliter per minute (mL/min) at screening.
• Has tattoo(s) or scarring at or near the site of intravenous infusion or any other condition which may interfere with infusion site examination, in the opinion of the Investigator.
• Has infrequent bowel movements (less than approximately once per day) within 30 days prior to first dosing.
• Has received radiolabeled substances or has been exposed to radiation sources within 12 months of first dosing or is likely to receive radiation exposure or radioisotopes within 12 months of first dosing such that participation in this study would increase their total exposure beyond the recommended levels considered safe (that is weighted annual limit recommended by the International Commission on Radiological Protection [ICRP] of 3000 milli roentgen equivalent man [mrem]).
• Has been on a diet incompatible with the on-study diet, in the opinion of the Investigator or designee, within the 30 days prior to the first dosing and throughout the study.
• Donation of blood or significant blood loss within 56 days prior to the first dosing.
• Plasma donation within 7 days prior to the first dosing.