Inclusion Criteria:

- 1. Aged between 18 and 75 years, extremes included, male or female

- 2. Laboratory (RT-PCR) and clinical symptoms confirmed case of 2019-nCoV pneumonia,
according to the official guideline "Pneumonia Diagnosis and Treatment Scheme for
Novel Coronavirus Infection (Trial Version 5)"

- 3. Hospitalised with a new onset respiratory illness (≤7 days since illness onset)

- 4. No family planning within six months, and agree to take effective contraceptive
measures throughout the study and for at least 30 days after the final study drug dose

- 5. Must agree not to enroll in another study of an investigational agent prior to
completion of Day 30 of study

- 6. Informed Consent Form (ICF) signed voluntarily

Exclusion Criteria:

- 1. Severe 2019-nCoV pneumonia met one of the following criteria: respiratory distress,
RR ≥ 30 times / min, or SaO2 / SpO2 ≤ 93% in resting state, or arterial partial
pressure of oxygen (PaO2) /concentration of oxygen (FiO2) ≤ 300mmHg (1mmHg = 0.133kpa)

- 2. Critical severe 2019-nCoV pneumonia met one of the following criteria: respiratory
failure and mechanical ventilation required, or shock, or combined with other organ
failure required ICU monitoring treatment

- 3. Severe liver disease (e.g. Child Pugh score ≥ C, AST > 5 times upper limit)

- 4. Known allergic reaction to any of components of ASC09 / ritonavir compound tablets

- 5. Patients with definite contraindications in the label of ritonavir

- 6. Positive serum pregnancy test result for women with childbearing potential at
screening

- 7. Using HIV protease inhibitor drugs

- 8. Not suitable for the study, in the opinion of the Investigator (e.g. patient may be
transferred to another hospital during the study period, patient with multiple basic
diseases, etc.)