CX-4945 in Viral Community Acquired Pneumonia

Domain I: SARS-CoV-2 domain * Arm 1: CX-4945 (400 mg BID for 5 days) +SOC * Arm 2: Placebo + SOC Domain II: Influenza virus domain * Arm 3: CX-4945 (400 mg BID for 5 days) +SOC * Arm 4: Placebo + SOC Screening visit will collect health information and perform protocol specified tests to determine patients' eligibility. After screening visit, eligible subjects who fulfill all selection criteria for enrollment will be randomized into each of the arms. The CX-4945 will be administered at 400 mg BID for 5 days. Subjects will be followed up until Day 29.