This is a double-blind (test or experiment in which neither the person giving the treatment nor the patient knows which treatment the patient is receiving), placebo-controlled, randomized (study medication assigned to participants by chance) and single-center study of JNJ-63623872. The duration of study will be approximately 5.5 weeks for each ISO per participant. The study consists of 3 parts: Screening Phase (28 days before study commences on Day 1); double-blind Treatment Phase (single oral dose of JNJ-63623872 or placebo on Day 1 under fasted condition); and Follow up Phase (up to 7-10 days after study drug administration). All the eligible participants will be randomly assigned to 1 of 3 groups. The planned doses will be escalated in a stepwise fashion if the safety and tolerability in the preceding dose is found acceptable. Participants in Group 1 will receive JNJ-63623872 300 milligram (mg) or placebo, Group 2 will receive JNJ-63623872 600 mg or placebo and Group 3 will receive JNJ-63623872 1200 mg or placebo. Study drug will be administered following a 10-hour overnight fast. Blood samples will be collected for evaluation of pharmacokinetics at pre-dose and post-dose of study treatment. Pharmacokinetics of JNJ-63623872 will be evaluated primarily. Participants' safety will be monitored throughout the study.
The purpose of this study is to evaluate the safety, tolerability, and pharmacokinetics of JNJ-63623872 following oral administration of single ascending dose of JNJ-63623872 in healthy Japanese adult participants.