A Study to Investigate the Safety, Tolerability, and Pharmacokinetics of JNJ-64264681 in Healthy Male and Female Participants

A Double-blind, Placebo-controlled, Randomized, Single and Multiple Ascending Dose Study to Investigate the Safety, Tolerability, and Pharmacokinetics of JNJ-64264681 in Healthy Male and Female Subjects

The primary purpose of this study is to investigate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of JNJ-64264681 in healthy participants after single and multiple oral doses.

Inclusion Criteria:

• Participant must have a body mass index (BMI) between 18.0 and 30.0 kilogram per meter square (kg/m^2) (BMI = weight[kg]/height[m]^2), and a body weight of not less than 50 kilogram (kg)
• Participant must be healthy on the basis of physical examination, medical history, vital signs, and 12-lead Electrocardiogram (ECG) performed at screening and Day -1
• Participant must be healthy on the basis of clinical laboratory tests performed at screening and Day -1. If the results of the serum chemistry panel, coagulation, hematology, or urinalysis are outside the normal reference ranges, 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
• Participant must sign an informed consent form (ICF) indicating that he or she understands the purpose of, and procedures required for, the study and is willing to participate in the study
• Female participants must not be of childbearing potential by fulfilling 1 of the criteria below: a) Be over 45 years of age with no menses for 12 months without an alternative medical cause, with screening follicle stimulating hormone (FSH) levels of greater than (>)40 International Units Per Liter (IU/L) or milli-international units per milliliter (mIU/mL). b) Be permanently surgically sterile. Permanent surgical sterilization methods include hysterectomy, bilateral salpingectomy, bilateral tubal occlusion/ligation procedures, and bilateral oophorectomy. Documentation of FSH levels is not required in the case of surgical sterility

Exclusion Criteria:

• Participant has current, or history of clinically significant medical illness including, but not limited to, liver or renal insufficiency, significant cardiac (including heart valve disease), vascular, pulmonary, gastrointestinal, endocrine, neurologic, hematologic, rheumatologic, psychiatric, or metabolic disturbances
• Participant has a history of abnormal bleeding or bruising
• Participant has a history of atrial fibrillation or history of arrhythmias
• Participant has history of malignancy within 5 years before screening (exceptions are squamous and basal cell carcinomas of the skin and carcinoma in situ of the cervix, or malignancy, which in the opinion of the investigator, with concurrence with the sponsor's medical monitor, is considered cured with minimal risk of recurrence)
• Participant has known allergies, hypersensitivity, or intolerance to polyethylene glycol 400 (PEG400) (vehicle for JNJ-64264681 for oral solution dosing) for participant in a cohort where study drug is to be dosed as an oral solution, or to microcrystalline cellulose, lactose monohydrate, croscarmellose sodium, silica dioxide, sodium lauryl sulfate, magnesium stearate, or gelatin (excipients in the solid dose formulation (capsule) of JNJ-64264681) for participant in a solid dose formulation cohort