This is a Phase II, multi-center, double-blind, randomized, interventional study in approximately 120 subjects to evaluate clinical benefit of CX-4945 in adult outpatients with SARS-CoV-2 and influenza viral infection-associated pneumonia. The subjects will be recruited into two domains, including SARS-CoV-2 and influenza virus domains. The study will compare the efficacy of Standard of Care (SOC) combined with CX-4945 against SOC paired with a placebo, utilizing a 1:1 allocation ratio in each domain.