A Study to Evaluate the Pharmacokinetics (PK), Safety and Tolerability of TAK-788 Followed by Evaluation of the Effects of a Low-Fat Meal on TAK-788 PK and Evaluation of Relative Bioavailability of TAK-788 Capsules in Healthy Participants

The drug being tested in this study is called TAK-788. The study will assess the safety and tolerability of single oral dose of TAK-788, evaluate the effect of a low-fat meal on PK of TAK-788 and will assess the relative bioavailability of two DiCs of TAK-788.

The study will enroll approximately 69 participants. The study is designed to consist of 3 parts: Part 1- dose escalation phase, Part 2- low fat meal effect and Part 3 - relative bioavailability. The study population of Part 1 will consist of 40 participants enrolled into 5 cohorts. Each cohort will have 8 randomized participants with 6 receiving a single dose of TAK-788, and 2 receiving matching placebo under fasted conditions. In Cohorts 1 to 5, safety of single-dose TAK-788 will be evaluated. For Part 2, the effect of a low-fat meal on a single tolerable dose of TAK-788 will be determined following review of safety and tolerability data from the previous cohorts in Part 1. The study population of Part 2 will consist of 16 participants enrolled into 2 cohorts of different doses, where participants will be randomized to a cross-over sequence of:

• TAK-788 Fed + TAK-788 Fasted
• TAK-788 Fasted + TAK-788 Fed

The study population of Part 3 will consist of 13 participants enrolled into 1 cohort, where participants will be randomized to a cross-over sequence of:

• TAK-788 DiC (reference) + TAK-788 DiC (test)
• TAK-788 DiC (test) + TAK-788 DiC (reference) This single-center trial will be conducted in the United States. The overall time to participate in this study is approximately 7 months. Participants will be contacted by telephone 30 days after the last dose of study drug for a follow-up assessment.

Inclusion criteria

• Body weight of greater than or equal to (>=) 45 kilogram (kg) (women) or >=55 kg (men) and a body mass index of 18.0 to 30.0 kilogram per square meter (kg/m^2) at screening.
• Nonsmoker (never smoked or greater than [>] 20 years from last occurrence of smoking).
• Normal organ function including hepatic, renal, and bone marrow function.

Exclusion criteria

• Manifestations of malabsorption due to prior gastro-intestinal (GI) surgery, GI disease, or for an unknown other reason that may alter the PK of TAK-788.
• Pulmonary infection ongoing or within 30 days of informed consent.
• Inability to undergo venipuncture and/or tolerate venous access.
• Inability to tolerate multiple blood sampling.
• Ongoing or active infection, including but not limited to, the requirement for intravenous (IV) antibiotics.