Evaluate the Efficacy and Safety of FB2001 for Inhalation in Patients With Mild to Moderate COVID-19

Coronavirus Disease 2019 (COVID -19) is a respiratory illness that can spread from person to person. The infectious agent that causes COVID -19 is a novel coronavirus, named severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), was first identified during a recent outbreak in December 2019, Patients with COVID-19 have symptoms of fever, cough, and shortness of breath along with non-specific symptoms including myalgia and fatigue. FB2001 is a small-molecule inhibitor of coronavirus 3CL protease(3CLpro). In phase I clinical trial, FB2001 for Inhalation were safe and tolerable well in healthy subjects, and were projected to be effective in patients according to its pharmacokinetic profile. This study is a double-blind, randomized, placebo-controlled study to evaluate the efficacy and safety of FB2001 for Inhalation in patients with mild to moderate Coronavirus Disease 2019 (COVID-19). The subjects will be randomized in a 1:1 ratio to FB2001 group or placebo group while both receiving standard of care treatment.