A Multi-center,Randomized,Double-blind,Placebo-controlled,Phase 3 Study Evaluating Favipiravir in Treatment of COVID19

Inclusion Criteria:

1. Voluntarily participating in the clinical study; fully understanding and being fully
informed of the study and having signed the Informed Consent Form (ICF); willingness
and capability to complete all the study procedures;

2. Age 18-75 years (inclusive) at the time of signing ICF;

3. Being confirmed with COVID-19-Moderate type according to Competent Authority and
Ministry of Health and respective country guidelines and recommendations reported in
Appendix 1 (a, b, c, d) to the present protocol. Based on comprehensive analysis and
judgement taking into account both the epidemiological history and clinical
manifestations, the diagnosis is to be confirmed for suspected cases or suspected
cases/clinically diagnosed cases with all of the following etiological evidences:

- Positivity in RT-PCR 2019-nCov test on respiratory tract specimens;

- High homology with known gene sequence of 2019-nCov in viral gene sequencing on
respiratory tract specimens.

4. Chest imaging (CT as first option or X-ray if CT not possible)-documented pneumonia;
if CT cannot be performed, Pneumonia confirmed by X-ray may be used. The method of
chest imaging pneumonia diagnosis must be consistent all through the study period;

5. Patients with pyrexia (axillary ≥37℃ or oral ≥ 37.5℃, or tympanic or rectal≥38℃) or
either respiratory rate >24/min and <30/min or cough; For not hospitalized patients,
the Investigator should maintain the detection method consistent through study period.
In addition, the Investigator should maintain the data collection and quality
compliant with GCP requirements.

6. The interval between symptoms onset and randomization is no more than 10 days;
symptoms onset is primarily based on pyrexia, and can be based on cough or other
related symptoms for patients without experiencing pyrexia following onset (it is
strongly recommended that the interval between symptoms onset and randomization should
not exceed 5 days);

7. For female subjects: evidence of post-menopause, or, for pre-menopause subjects,
negative pre-treatment serum or urine pregnancy test. Menopause is defined as
amenorrhea for at least 12 months without other medical cause, with the following
age-specific requirements:

- For female subjects aged <50 years: menopause for at least 12 months following
withdrawal of exogenous hormonal therapy, with LH or FSH within the
post-menopausal ranges, or having undergone any contraceptive surgery (bilateral
oophorectomy or hysterectomy);

- For female subjects aged ≥ 50 years: menopause for at least 12 months following
withdrawal of exogenous hormonal therapy, or having undergone
radiotherapy-induced oophorectomy with amenorrhea >1 year, or having undergone
chemotherapy-induced menopause with amenorrhea>1 year, or having undergone any
contraceptive surgery (bilateral oophorectomy or hysterectomy).

8. Eligible subjects of child-bearing age (male or female) must agree to take effective
contraceptive measures (including hormonal contraception, barrier methods or
abstinence) with his/her partner during the study period and for at least 3 months (in
male) and 1 month (in female)following the last study treatment; in addition:

1. For female participants of childbearing potential only highly effective methods
(failure rate < 1 %) plus one barrier method is allowed throughout the period of
relevant systemic exposure with Favipiravir. Double barrier methods alone are not
considered as highly effective. Additionally, pregnancy testing at baseline only
is not deemed sufficient and must be repeated more frequently, at least if
clinical signs of pregnancy occur and at follow-up / end of study.

2. male participants, if vasectomized or not, must wear a condom each time having
heterosexual intercourse throughout the period of relevant systemic exposure with
Favipiravir (as it is distributed to seminal fluid).

3. male participant must be instructed not to have intercourse with pregnant women
throughout the period of relevant systemic exposure with Favipiravir.

4. For further details on contraception in clinical trials, please refer to the CTFG
guidance: https://www.hma.eu/fileadmin/dateien/Human_Medicines/01-
About_HMA/Working_Groups/CTFG/2014_09_HM A_CTFG_Contraception.pd

9. Not participating in any other drug clinical studies before completion of the present
study.

Exclusion Criteria:

1. Where, in the opinion of the investigator, participation in this study will not be in
the best interest of the subject, or any other circumstances that prevent the subject
from participating in the study safely;

2. Refractory nausea, vomiting, or chronic gastrointestinal disorders, inability to
swallow the study drug or having undergone extensive bowel resection which may affect
adequate absorption of Favipiravir;

3. Severe liver disease: underlying liver cirrhosis or alanine aminotransferase
(ALT)/aspartate aminotransferase (AST) elevated over 5 times the ULN;

4. Gout/history of gout or hyperuricemia (above the ULN);

5. Oxygen saturation (SPO2) ≤93% or arterial oxygen partial pressure (PaO2)/ fraction of
inspired O2 (FiO2) ≤300 mmHg;

6. Known allergy or hypersensitivity to Favipiravir or any of its excipients, or to
placebo excipients

7. Known severe renal impairment [creatinine clearance (CrCl) <30 mL/min] or having
received continuous renal replacement therapy, hemodialysis or peritoneal dialysis;

8. Possibility of the subject being transferred to a non-study hospital within 72h;

9. Pregnant or lactating women;

10. Having used Favipiravir or participated in any other interventional drug clinical
study within 30 days prior to first dose of study drug or having received treatments
with other Investigational Medicinal Products (IMPs) or previous therapies within two
weeks or five times the half-life of the drug, whichever is longer, must lead to
exclusion

11. Persons, who were placed in an institution due to official or legal orders should be
excluded

12. Persons, who are dependent on the sponsor, the investigator or the trial site, meaning
that the voluntary nature of their consent is no longer guaranteed, must be excluded
from participation