Inclusion Criteria:

1. Age ≥18 and ≤90 years.

2. History of hospitalization for COVID-19 pneumonia, as documented by positive RT/PCR
testing for SARS-Cov-2 infection (nasopharyngeal swab) and suggestive radiological
findings at the chest CT scan.

3. Resolution of SARS-CoV-2 infection as defined by negative RT/PCR testing
(nasopharyngeal swab).

4. Evidence of residual interstitial lung abnormalities (including any of the
following: ground glass, reticulation, or consolidation with overall extent ≥5% of
total lung volume) on chest high resolution CT scan (performed during screening or
within 30 days from screening visit) AND

One or more of the following:

- DLco ≤ 70 % of predicted value at screening

- Oxygen desaturation at 6-minute walk test (6MWT) ≥4% from baseline value at
screening.

- Total Lung Capacity ≤ 80 % of predicted value at spirometry performed at screening

- Exertional dyspnea at screening, as defined by MMRC ≥1

Exclusion Criteria:

1. Evidence of resting respiratory failure, as defined by PaO2 ≤60 mmHg (FiO2 21%) at
blood gas analysis at screening.

2. History of interstitial lung disease, or evidence of interstitial lung disease at
screening that suggests any of the following: idiopathic interstitial pneumonias;
lung diseases related to exposure to fibrogenic agents or other environmental toxins
or drugs; other types of occupational lung diseases; granulomatous lung diseases;
pulmonary vascular diseases; systemic diseases, including vasculitis, infectious
diseases (Other than SARS-Cov-2 infection) and connective tissue diseases.

3. History of other types of respiratory diseases, including disorders of the airways,
lung parenchyma, pleural space, mediastinum, diaphragm, or chest wall that, in the
opinion of the Investigator, would impact the primary protocol endpoint or otherwise
preclude the subject's participation in the study.

4. Any other known disease, medical conditions or blood test abnormalities that in the
opinion of the Investigator may put the patient at risk because of participation,
interfere with study procedures or cause concern regarding the patient inability to
participate in the study.

5. Concomitant treatment with oral corticosteroids and/or other immunosuppressive
drugs.

6. Pregnancy status.

7. Incapacity of providing valid informed consent.