A Study of JNJ-64281802 in Participants With Confirmed Dengue Fever

A Phase 2a, Randomized, Double-blind, Placebo-controlled Trial to Evaluate the Antiviral Activity, Safety and Tolerability, and Pharmacokinetics of JNJ-64281802 in Participants With Confirmed Dengue Fever

The purpose of this study is to investigate the antiviral activity of JNJ-64281802 versus placebo in terms of reduction of dengue virus (DENV) ribonucleic acid (RNA) in primary DENV infection.

Inclusion Criteria:

• Participant with a referral note/documentation from a health care facility or practitioner indicating non-structural 1 protein (NS1) positive for dengue virus (DENV), positive NS1 rapid test at pre-screening during an ambulatory visit, or participant who tests NS1 positive at the site
• Participant reported a fever with an onset within the last 48 hours
• A woman of childbearing potential must have a negative serum pregnancy test at screening
• A woman must be: a. not of childbearing potential, b. of childbearing potential and practicing a highly effective, preferably user-independent method of contraception (failure rate of less than [<] 1% per year when used consistently and correctly) and agrees to remain on a highly effective method while receiving study intervention and until at least 90 days after last dose- the end of relevant systemic exposure
• A male participant must agree not to donate sperm for the purpose of reproduction during the study and for a minimum of 90 days after receiving the last dose of study intervention

Exclusion Criteria:

• Participant with any clinical signs and symptoms for severe dengue according to the world health organization (WHO) criteria (such as severe plasma leakage leading to dengue shock syndrome [DSS], fluid accumulation with respiratory distress, severe bleeding, sever organ involvement)
• Use of any cytochrome 3A4 (CYP3A4) inducers (example, phenytoin, rifampin), UDP glucuronosyltransferase family 1 member A9 (UGT1A9) inducers (example, rifampin), or substrates for CYP3A4 with a narrow therapeutic range (example, alfentanil, cyclosporin), or sensitive breast cancer resistance protein (BCRP) substrates (example, pravastatin and folic acid) from 14 days before first dose of study drug until 28 days after last dose of study drug. Systemic use of strong CYP3A4 inhibitors (example, clarithromycin, itraconazole) or UGT1A9 inhibitors (example, probenecid, mefenamic acid) from 7 days before first dose of study drug until 28 days after last dose of study drug
• 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 is considered cured with minimal risk of recurrence)
• Had major surgery, (example, requiring general anesthesia) within 4 weeks before screening, or will not have fully recovered from surgery, or has surgery planned during the time the participant is expected to participate in the study
• Known or suspected congenital or acquired immunodeficiency; or receipt of immunomodulation therapy such as anti-cancer chemotherapy or radiation therapy; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months)