A Study to Investigate Safety, Tolerability, and Pharmacokinetics of JNJ 53718678 in Healthy Japanese Adult Participants

A Double-blind, Placebo-controlled, Randomized, Single Ascending Dose Study to Investigate Safety, Tolerability, and Pharmacokinetics of JNJ 53718678 in Healthy Japanese Adult Subjects

The purpose of this study is to investigate the safety, tolerability, and pharmacokinetics of three dosages (250, 500, and 1000 milligram [mg], or maximum tolerated dose [MTD]) of JNJ 53718678 when administered as single dose in fasting conditions in healthy Japanese adult participants in 3 cohorts.

This is a Phase 1, single center, double-blind (study in which neither the researchers nor the participants know what treatment the participants are receiving), placebo-controlled (study in which the experimental treatment or procedure is compared to placebo treatment), randomized (study medication assigned to participants by chance) study in healthy Japanese adult participants residing outside of Japan. The study will consist of a Screening phase, an In-clinic treatment phase, and a follow-up phase. The study duration for each participant will be approximately 6 weeks from Screening (Day -28 to Day -2) to follow up visit (Day 10 to 14). Participants will be randomly assign to receive JNJ 53718678 or placebo, at planned dose of 250, 500 and 1000 milligram (mg). Planned doses will be stepwise escalated, if the safety and tolerability of the preceding dose(s) are found to be acceptable, and the maximum tolerated dose (MTD) is not reached. De-escalation may be performed in order to study an intermediate dose. The safety, tolerability and pharmacokinetic (PK) profile of JNJ-53718678 will primarily be evaluated. Participants' safety will be monitored throughout the study.

Inclusion Criteria:

• Participant must be a Japanese participant who has resided outside Japan for no more than 5 years and whose parents and grandparents are Japanese as determined by participant's verbal report
• Participant must be healthy on the basis of a medical evaluation that reveals the absence of any clinically relevant abnormality and includes a physical examination (including height and body weight measurement and skin examination), medical history, vital signs (body temperature, systolic blood pressure, diastolic blood pressure, pulse rate, orthostatic hypotension, and respiratory rate), and the results of blood biochemistry, blood coagulation and hematology tests, a urinalysis, and a hematest performed at Screening, on Day -1, or Day 1 pre-dose, whichever is applicable. If there are abnormalities, the participant may be included only if the Investigator judges the abnormalities or deviations from normal to be not clinically significant. This determination must be recorded in the participant's source documents and initialed by the Investigator
• Female participants must be of non-childbearing potential: postmenopausal for at least 2 years (amenorrheal for at least 2 years and a serum follicle stimulating hormone [FSH] level greater than [>] 40 international unit per liter [IU/L] or milli IU per milliliter [mIU/mL]), or surgically sterile (have had a total hysterectomy, bilateral oophorectomy, or bilateral tubal ligation/bilateral tubal clips without reversal operation), or otherwise incapable of becoming pregnant
• Participant must be a non-smoker for at least one month prior to Screening
• Participant must have a body mass index (BMI) (weight [kilogram{kg}]/height^2 [meter^2]) between 18 and 30 kg/m^2 (inclusive), and body weight not less than 50 kg

Exclusion Criteria:

• Participant has a history of or current clinically significant medical illness including (but not limited to) cardiac arrhythmias or other cardiac disease, hematologic disease, coagulation disorders (including any abnormal bleeding or blood dyscrasias), lipid abnormalities, significant pulmonary disease, including bronchospastic respiratory disease, diabetes mellitus, hepatic or renal insufficiency, thyroid disease, neurologic or psychiatric disease, infection, or any other illness that the Investigator considers should exclude the subject or that could interfere with the interpretation of the study results
• Participant with any history of clinically significant skin disease such as, but not limited to, dermatitis, eczema, drug rash, psoriasis, food allergy, and urticaria
• Clinically significant abnormal physical examination, vital signs, or 12 lead electrocardiogram (ECG) at Screening, on Day -1 (physical examination only), and pre-dose on Day 1, as deemed appropriate by the Investigator
• Participants with lack of good/reasonable venous access
• Participants with a past history of heart arrhythmias (extrasystoli, tachycardia at rest) or, history of risk factors for Torsade de Pointes syndrome (for example, hypokalemia, family history of long QT Syndrome