Efficacy and Safety of Longidaza® for the Treatment of Patients With Residual Changes in the Lungs After COVID-19

Inclusion Criteria:

1. Male and female patients aged 18 to 80 years, who signed an informed consent form.

2. The condition after infection with COVID-19, documented in the period from 1 to 12months before screening (ICD-10: U07.1, U07.2), including accompanied byhospitalization of the patient.

3. The presence of a negative result of the polymerase chain reaction test (PCR) duringscreening and an express test for the SARS-CoV-2 antigen at visit 2.

4. The presence of respiratory symptoms (at least dyspnea), while the severity ofdyspnea on the mMRC during screening is ≥ 1 point.

5. The value of hemoglobin oxygen saturation: SpO2 < 95% at rest at the screening;and/or desaturation (decrease of SpO2 by ≥ 4% in the 6MWT relative to the value atrest) at the screening.

6. The presence of residual changes in the lung parenchyma characteristic of previousCOVID-19 infection, > 10% of the area, according to CT at the screening

7. Respiratory dysfunction of the restrictive type at the screening: FVC < 80%, FVC 1 /FVC > 70%.

Exclusion Criteria:

1. A history of chronic respiratory diseases (interstitial lung disease, chronicobstructive pulmonary disease, bronchial asthma, bronchiectasis, lung cancer).

2. Clinical signs or anamnesis data on the presence of diseases that, according to theresearcher, can lead to restrictive changes in respiratory function (pronouncedkyphoscoliosis, pleural effusion, neuromuscular diseases), pathological obesity,etc.

3. Clinical signs or anamnesis data on the presence of unstable angina pectoris, stableangina pectoris of high functional class, clinically significant cardiacarrhythmias, chronic heart failure, pulmonary hypertension, suffered pulmonaryembolism or acute myocardial infarction in within 6 months prior to screening.

4. Dyspnea of any other etiology: thyrotoxicosis, anemia (hemoglobin less than 100g/l), pathological obesity (BMI ≥ 40 kg/m2), metabolic acidosis, neuromusculardiseases according to anamnesis or screening examination.

5. The presence of an acute infectious process of any etiology and localization.

6. Allergic reactions to the administration of azoximer bovhyaluronidase or anauxiliary component of the studied drug (mannitol) in the anamnesis.

7. Clinical signs of pulmonary hemorrhage and/or hemoptysis during examination and inthe anamnesis.

8. Confirmed eye injuries with vitreous hemorrhage during the last 6 months accordingto the medical history.

9. Malignant neoplasms of any localization in the anamnesis, with the exception of insitu carcinoma, which required only surgical treatment.

10. Renal failure.

11. Taking drugs of prohibited therapy since the start of screening in this study.

12. Serological test positive for HIV infection, viral hepatitis B and C.

13. Pregnancy or breastfeeding.

14. Participation in clinical trials of an experimental drug within 30 days prior toscreening for participation in the current study.

15. Any other medical or social conditions that, in the opinion of the researchphysician, do not allow the patient to participate in this study.