The drug being tested in this study is called TAK-831. TAK-831 is being tested to treat participant who have schizophrenia and cerebellar ataxia. This study will look at the PK, safety and tolerability of TAK-831 in healthy participants. The study will enroll approximately 120 participants. The study will include 4 parts: Part 1 (single-rising dose [SRD]), Part 2 (SRD/multiple-rising dose [MRD]), Part 3 (MRD) and Part 4 (relative bioavailability study). Participants will be randomly assigned (by chance, like flipping a coin) to receive either active drug TAK-831 or placebo which will remain undisclosed to the participant and study doctor during the study (unless there is an urgent medical need):~Part 1, Cohort 1: single dose of TAK-831 100 mg~Part 1, Cohort 2: single dose of TAK-831 250 mg~Part 1, Cohort 3: single dose of TAK-831 500 mg~Part 1, Cohort 4: single dose of TAK-831 30 mg~Part 1, Cohort 5: single dose of TAK-831 750 mg~Part 1, Cohort 6: single dose of TAK-831 10 mg~Part 2, Cohort 1: single dose of TAK-831 30 mg~Part 2, Cohort 2: single dose of TAK-831 100 mg~Part 2, Cohort 3: single dose of TAK-831 200 mg~Part 2, Cohort 4: single dose of TAK-831 400 mg~Part 3, Cohort 1: TAK-831 400 mg~Part 4: TAK-831 100 mg (Tablet Fasted + Tablet Fed + Suspension Fasted)~Part 4: TAK-831 100 mg (Tablet Fed + Tablet Fasted + Suspension Fasted)~Part 4: TAK-831 100 mg (Suspension Fasted+ Tablet Fed + Tablet Fasted)~Dosing with TAK-831 will progress into study Part 2, 3 and 4, only after review of all available safety, tolerability, and PK data collected in Cohorts 1 to 6 of the Study Part 1. This single center trial will be conducted in the United Kingdom. The overall time to participate in this study is approximately up to 58 days. Participants will be admitted in the clinic for the up to 20 days, and will be contacted by telephone 14 days after last dose of study drug for a follow-up assessment.~The study was terminated by Takeda due to the discomfort observed in the study participants from the CSF collection procedure in Part 3 of the study, hence it is was not feasible to collect further CSF samples that were required to meet the exploratory objectives of the study. Part 1, 2 and 4 of the study were completed as planned.
The purpose of this study is to determine the safety, tolerability and pharmacokinetics (PK) of single and multiple rising doses of TAK-831 in healthy participants.