An Adaptive Study of Favipiravir Compared to Standard of Care in Hospitalized Patients With COVID-19

Inclusion Criteria:

1. Signed Patient Information Sheet and Informed Consent form to participate in the
study.

2. Men and women aged 18 years and older.

3. Patients hospitalized with a diagnosis of COVID-19.

4. The diagnosis of COVID-19 was confirmed by positive reverse transcription polymerase
chain reaction (RT-PCR) test for SARS-CoV-2, performed no earlier than 7 days before
hospitalization or at screening.

5. Moderate severity of COVID-19 with pneumonia with at least 1 of the following
symptoms:

- Fever above 38 °C;

- Cough;

- Shortness of breath during physical exertion;

- C reactive protein (CRP) of blood serum > 10 mg/l;

- SpO2 < 95%

6. The capability of oral drug administration.

7. The patients' consent to use adequate contraception methods during the study (condom
with spermicide) and for 3 months following completion.

Exclusion Criteria:

1. Severe type of disease, with at least one of the following criteria:

- Frequency of breath > 35 per minute, which does not decrease after the body
temperature drops to normal or subfebrile values;

- Blood oxygen saturation (SpO2) < 90% at rest;

- Partial pressure of oxygen in arterial blood (PaO2) < 60 mm Hg;

- Oxygenation index (RaO2/FiO2) ≤ 200 mm Hg;

- Partial pressure of CO2 in arterial blood (PaCO2) < 60 mm Hg;

- Septic shock.

2. Patients treated with lopinavir/ritonavir, ribavirin, arbidol, chloroquine,
hydroxychloroquine, mefloquine, favipiravir within 7 days prior to screening.

3. Severe cardiovascular diseases currently or 6 months prior to randomization,
including: New York Heart Association (NYHA) Class III or IV chronic heart failure,
clinically significant ventricular arrhythmias (ventricular tachycardia, ventricular
fibrillation), unstable angina, myocardial infarction, heart and coronary vessel
surgery, significant valvular heart disease, uncontrolled arterial hypertension with
systolic blood pressure > 180 mm Hg and diastolic blood pressure > 110 mm Hg,
pulmonary embolism or deep vein thrombosis.

4. Severe chronic renal impairment (GFR < 30 ml / min) or continuous renal replacement
therapy, hemodialysis or peritoneal dialysis.

5. A history of cirrhosis or an increase in alanine aminotransferase (ALT) and / or
aspartate aminotransferase (AST) > 5 times × upper limit of normal (ULN).

6. Severe diseases of the central nervous system, including seizures in history or
conditions that may lead to their development; stroke or transient ischemic attack
within 12 months prior to screening; head injuries or loss of consciousness within 12
months prior to screening; a brain tumor.

7. Significant uncontrolled concomitant disease, e.g. neurological, renal, hepatic,
endocrinological or gastrointestinal disorder which according to the Investigator,
could prevent the patient from participating in the study

8. Malignancies that require chemotherapy within 6 months prior to screening.

9. Known HIV infection

10. Hypersensitivity to any component of the study drug.

11. Participation in other clinical studies or taking other study drugs within 28 days
prior to screening.

12. Pregnant or lactating women or women planning to get pregnant during the clinical
study; women of child-bearing potential (including non-sterilized by surgical means
and during the post-menopause period less than 2 years) who do not use adequate
contraception methods.

13. Inability to read or write, unwillingness to understand and follow procedures of study
protocol, as well as any other concomitant medical or serious mental conditions that
make the patient unfit to participate in the study, limit the legality of obtaining
informed consent or can affect patient's ability to participate in the study.