To Evaluate The Safety and Efficacy of STSA-1002 Injection in Patients With Acute Respiratory Distress Syndrome

Inclusion criteria

• 18 years old ≤ ≤ 85 years old;
• laboratory tests results indicate respiratory viral infection;
• Fulfills the diagnostic criteria for A New Global Definition of Acute Respiratory Distress Syndrome ;
• The time from the onset of respiratory infection-related symptoms to randomization is ≤ 12 days (for patients without invasive mechanical ventilation)/)/≤ 14 days (for patients with invasive mechanical ventilation); Or worsening of respiratory infection-related symptoms within ≤7 days from randomization;
• PaO2/FiO2≤200mmHg;
• The subjects (including their partners) have no plans to have children during the trial and within 3 months after the last dose, and agree to take appropriate and effective contraceptive measures (such as contraceptive pills, condoms, etc.);
• Volunteer to participate in the trial and sign the informed consent form.

Exclusion criteria

• ECMO before the first dose;
• According to the comprehensive judgment of the investigator, the patient's condition improved within 48 hours before the first dose;
• The expected survival period is no more than 24 hours or cardiac arrest occurred 4 weeks before the first dosedose;
• Patients with stroke or acute coronary syndrome within 3 months before randomization;
• Patients with cardiogenic pulmonary edema, which is the main cause of respiratory failure; New York Heart Classification III-IV patients;
• Severe chronic respiratory failure;
• Known active pulmonary tuberculosis;
• Combined with liver insufficiency
• Long-term dialysis and/or known severe renal impairment Cytomegalovirus infection;
• Known HIV infection with CD4+ T-lymphocyte count < 200 cells/μL;
• Organ transplant patients;
• Patients who received radiotherapy and chemotherapy in the past 1 years or the malignant tumor is still in the active phase;
• Septic shock
• Absolute neutrophil count is less than 0.5×109/L;
• Hemoglobin is less than 60g/L, or the researcher judges that there is active gastrointestinal bleeding;
• Severe underlying diseases with poor compliance with basic treatment;17. Pregnant or lactating women;

• Participated in new drug clinical trials and medication within 3 months before screening; 19. Allergic or allergic to any component of the trial drug and its excipients (such as allergic to two or more drugs); 20. Other diseases or conditions that the investigator considers unsuitable for participation in this trial.