A Study to Assess the Relative Oral Bioavailability of a Single Dose of JNJ-63623872/Oseltamivir Fixed-dose Combination Tablet and Single Agent Concept Formulations of JNJ-63623872 Compared to Their Respective Reference Formulation in Healthy Adult Participants

A Phase 1, Open-label, Randomized, Crossover Study in Two Panels of Healthy Adult Subjects to Assess the Relative Oral Bioavailability of a Single Dose of JNJ-63623872/Oseltamivir Fixed-dose Combination Tablet and Single Agent Concept Formulations of JNJ-63623872 Compared to Their Respective Reference Formulation

The purpose of this study is to assess the rate and extent of absorption of JNJ63623872 following administration of a single oral dose of 2*300 milligram (mg) given as 2 concept single agent tablet formulations compared to the administration of 2*300 mg JNJ63623872 reference tablets, under fasted conditions in healthy adult participants and to assess the rate and extent of absorption of JNJ63623872 and oseltamivir following administration of a single oral dose of 2*300 mg/37.5 mg JNJ63623872/ oseltamivir given as a concept fixed dose combination (FDC) tablet formulation compared to the coadministration of 2*300 mg JNJ63623872 tablets (reference formulation) and 1*75 mg oseltamivir capsule, under fasted conditions in healthy adult participants.

Inclusion Criteria:

• A female participant must have a negative serum beta-human chorionic gonadotropin pregnancy test at screening and on Day -1 in each treatment period
• Contraceptive use by men or women should be consistent with local regulations regarding the use of contraceptive methods for participant participating in clinical studies
• A female participant must agree not to donate eggs (ova, oocytes) for the purposes of assisted reproduction during the study and for at least 90 days after receiving the last dose of study drug
• Participant must have a body mass index (BMI), weight kilogram per height square meter square [kg]/height^2 [m]^2) between 18.0 and 30.0 kilogram per meter square (kg/m^2) (extremes included) at screening. The minimum weight will be 50.0 kilogram (kg)
• Participant must have a blood pressure (supine after at least 5 minutes rest) between 90 and 140 millimeters of mercury (mmHg) systolic, inclusive, and no higher than 90 mmHg diastolic at screening
• Participant must be non-smoker for at least 3 months prior to screening

Exclusion Criteria:

• Participant has history or current clinically significant medical illness including (but not limited to) cardiac arrhythmias or other cardiac disease, hematologic disease, coagulation disorders, lipid abnormalities, significant pulmonary disease, diabetes mellitus, hepatic or renal insufficiency, gastrointestinal disease, thyroid disease, neurologic or psychiatric disease, infection, or any other illness that the Investigator considers should exclude the participant or that could interfere with the interpretation of the study results
• Participant with a past history of heart arrhythmias (extrasystoli, tachycardia at rest), or history of risk factors for Torsade de Pointes syndrome (eg, hypokalemia, family history of long QT Syndrome)
• Participant with any history of clinically significant skin disease such as, but not limited to, dermatitis, eczema, drug rash, psoriasis, food allergy, or urticaria
• Participant has known allergy to heparin or history of heparin induced thrombocytopenia
• Participant has donated blood or blood products or had substantial loss of blood (more than 500 milliliter (mL) within 3 months before the first administration of study drug or intention to donate blood or blood products during the study
• A woman who is pregnant, or breast-feeding, or planning to become pregnant during this study, or a woman of childbearing potential who is unwilling to use acceptable methods of contraception
• Participant has a history of hepatitis B surface antigen (HBsAg) or hepatitis C virus (HCV) antibody positive, or other clinically active liver disease, or tests positive for HBsAg or anti-HCV at screening
• Participant has a history of human immunodeficiency virus type 1 (HIV-1) or HIV-2 infection, or tests positive for HIV-1 or -2 at screening