(1) Patients with a definitive diagnosis of COVID-19 and written informed consent.(2) Patients with oxygen saturation of more than 94% at room air and having either or both of the following: a. Pneumonia shadow on chest imaging b. Having more than one risk factors of the followings:Diabetes mellitus, Cardiovascular disease (coronary disease, stroke, peripheral arterial disease, heart failure), Chronic obstructive pulmonary disease, chronic kidney disease (30 <= eGFR < 60), Obesity (BMI >= 30), Elderly (age >= 65 )(3) Patients hospitalized within 5 days after the onset of symptoms and with the ability of administrating the investigational drug by the second day of hospitalization(4) Adult patients aged more than 20 at informed consent(5) Patients or partners of patients agreed to prevent pregnancy for 90 days from the day of initiating investigational drug(6) Patients being able to understand and willing to sign an IRB approved written informed consent document

(1) Patients with a definitive diagnosis of COVID-19 and written informed consent.(2) Patients with oxygen saturation of more than 94% at room air and having either or both of the following: a. Pneumonia shadow on chest imaging b. Having more than one risk factors of the followings:Diabetes mellitus, Cardiovascular disease (coronary disease, stroke, peripheral arterial disease, heart failure), Chronic obstructive pulmonary disease, chronic kidney disease (30 <= eGFR < 60), Obesity (BMI >= 30), Elderly (age >= 65 )(3) Patients hospitalized within 5 days after the onset of symptoms and with the ability of administrating the investigational drug by the second day of hospitalization(4) Adult patients aged more than 20 at informed consent(5) Patients or partners of patients agreed to prevent pregnancy for 90 days from the day of initiating investigational drug(6) Patients being able to understand and willing to sign an IRB approved written informed consent document