This is a randomized, double-blind, placebo-controlled Phase 2/3 study to evaluate the efficacy, safety, and antiviral activity of CP-COV03 in adult patients with dengue infection.

In Phase 2, approximately 210 patients with NS1-positive dengue within 72 hours of fever onset will be randomized to receive placebo or CP-COV03 at doses of 450, 900, or 1,350 mg/day for 7 days. An interim analysis by an independent Data and Safety Monitoring Board (DSMB) will support dose selection for Phase 3.

Inclusion Criteria:

• Patients who are 18 years or over of age at time of screening.
• Patients who have at least two symptoms with a score of 2 or higher within 72 h from fever onset.
• Patients who are diagnosed with dengue by NS1 positive (Phase 2- Part 1 only). And patients who are classified as dengue, zika, influenza, COVID-19 and others (Phase 3- Part 2 only)

Exclusion Criteria:

• Patients who show severe dengue (WHO dengue guideline C, any severe symptoms or clinical laboratory results)
• Patients who have previously received dengue vaccine
• Patients who have chronic medical conditions such as uncontrolled diabetes mellitus, severe asthma requiring oral steroids or admission to the hospital in the previous 6 months for cardiac disease