Study to Assess Efficacy and Safety of XC221 in the Treatment of Influenza and Other Acute Respiratory Viral Infections

Inclusion Criteria

• Men and women aged 18 to 45 years (inclusively).
• Clinically diagnosed influenza or ARVI.
• Patient's body temperature ≥37.5ºС and at least 1 symptom from Modified Jackson Scale estimated more than 2 points.
• Uncomplicated course of influenza or ARVI based on clinical estimations.
• The first 36 hours from the beginning of symptoms of influenza or ARVI.
• Women of reproductive age (who are not in menopause and who have not undergone surgical sterilization) and men who have sexual activity should use a reliable method of contraception (acceptable methods of contraception in this study are: intrauterine devices, oral contraceptives, contraceptive patch, long-acting injectable contraceptives, a double barrier method (condom and diaphragm with spermicide) throughout the study period.
• Compliance with the treatment regimen, visits and laboratory examinations provided by the protocol.
• Signed Informed Consent Form.

Exclusion Criteria

• Existence of complications of influenza or ARVI (including the presence / development of bacterial infection).
• Hypersensitivity to excipients of the drug XC221 or placebo.
• Antiviral medications in 7 days prior to screening (antiviral agents, interferons and interferon inducers, drugs that have immunomodulating action) or anti-infective agents of systemic or local action.
• Severe infection with signs of cardiovascular insufficiency development and other manifestations of infectious-toxic shock, as well as with the presence of neuroinfection syndrome (encephalic and meningoencephalic reactions, polyradiculoneuritis, neuritis).
• Signs of the development of viral pneumonia (the presence of two or more of the following symptoms): dyspnea, chest pain when coughing, systemic cyanosis, dullness of percussion sound with a symmetrical evaluation of the upper and lower sections of the lungs).
• Infectious diseases during the last week before including into the study.
• History of bronchial asthma.
• History of increased convulsive activity.
• Severe, decompensated or unstable somatic diseases (any diseases or conditions that are life-threatening or may worsen the patient's prognosis, and make him/her ineligible for the clinical study).
• History of oncological diseases, HIV, tuberculosis.
• Diabetes mellitus.
• Drug or alcohol abuse.
• Participation in any other clinical trial in the last 90 days.
• Pregnancy or lactation.
• Military or prison populations.
• Impossibility or inability to comply with the study procedures.
• A member of the investigator's family or other person interested in the results of the study.
• Abnormal laboratory results, which, according to the study doctor, interfere with the patient's inclusion in the study.
• History of renal insufficiency.