Epilepsy drug candidate put to the test in healthy volunteers

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: All Cohorts 1. Is capable of understanding and complying with protocol requirements. 2. Signs and dates a written, informed consent form and any required privacy authorization prior to the initiation of any study procedures including requesting that a participant fast for any laboratory evaluations. 3. Is a healthy male or female aged 18 to 55 years inclusive, at the time of informed consent and first study medication dose. 4. Weighs at least 45 kilogram (kg) and has a body mass index (BMI) from 18.0 to 30.0 kilogram per square meter (kg/m\^2), inclusive at Screening and Day -1. 5. Male participant who is non-sterilized and sexually active with a female partner of childbearing potential agrees to use adequate contraception from signing of informed consent throughout the duration of the study and for 30 days after last dose. 6. Female participant of childbearing potential who is sexually active with a non-sterilized male partner agrees to use routinely adequate contraception from signing of informed consent and throughout the duration of the study, and for 30 days after the last dose. 7. Can complete the CogState Battery at Screening. Additional Inclusion Criteria for Participants undergoing cerebrospinal fluid (CSF) Sampling (Part 2 only): 8. Agrees to spinal tap procedures for CSF collection. Exclusion Criteria: All Cohorts 1. Has received any investigational compound within 30 days prior to randomization. 2. Has received TAK-935 in a previous clinical study or as a therapeutic agent. 3. Has a significant history of uncontrolled, clinically significant neurologic (including seizure disorders), cardiovascular, pulmonary, hepatic, renal, metabolic, gastrointestinal, urologic, immunologic, endocrine disease or psychiatric disorder or endocrine disease or other abnormality or any significant results from physical examinations, or clinical laboratory results which may impact the ability of the participant to participate or potentially confound the study results. It is the responsibility of the investigator to assess the clinical significance; however, consultation with the Takeda Medical Monitor may be warranted. 4. Has a known hypersensitivity to any component of the formulation of TAK-935. 5. Has a history of drug abuse (defined as any illicit drug use) or a history of alcohol abuse within 1 year prior to the screening visit or is unwilling to agree to abstain from alcohol and drugs throughout the study. One unit is equivalent to a half-pint of beer or a single measure of spirits or 1 small glass of wine. 6. Has taken any excluded medication, supplements, or food products during the time periods listed in the Excluded Medications and Dietary Products table. Additional Exclusion Criteria for Participants undergoing CSF sampling (Part 2) 7. Has CSF collection performed within 30 days prior to check-in (Day -3). 8. Has a known hypersensitivity to the anesthetic or its derivatives used during CSF collection, or any medication used to prepare the area of lumbar puncture. 9. Has significant vertebral deformities (scoliosis or kyphosis) which, in the opinion of the investigator, may interfere with lumbar puncture procedure. 10. Has a history of clinically significant back pain and/or injury. 11. Has local infection at the puncture site.