Inclusion Criteria:

- ii. Hospitalized with COVID-19 pneumonia, based on chest X-ray or CT scan AND iii.
Evidence of hyperinflammation: IL-6>40pg/mL (if available) OR CRP >2 mg/dL OR ferritin
>2000 ng/mL AND iv. One or more of the following: impending need for requiring
invasive or non-invasive mechanical ventilation OR shock requiring vasopressor
(without evidence of bacterial / fungal infection) OR need for extracorporeal membrane
oxygenation (ECMO) OR severe, refractor ARDS (PaO2/FiO2<200 mmHg)

Exclusion Criteria:

Known severe allergic reactions to tocilizumab or other monoclonal antibodies

- Active tuberculosis infection based on history

- Suspected active bacterial, fungal, viral, or other infection (besides COVID-19)

- In the opinion of the investigator, progression to death is imminent and inevitable
within the next 24 hours, irrespective of the provision of treatments

- Have received oral anti-rejection or immunomodulatory drugs (including tocilizumab)
with the past 6 months

- Participating in other drug clinical trials (participation in COVID-19 trials allowed)

- Self-reported pregnant or breastfeeding

- Any serious medical condition or abnormality of clinical laboratory tests that, in the
investigator's judgment, precludes the patient's safe participation in and completion
of the study

- Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) > 10 x upper limit
of normal (ULN) detected within 24 hours at baseline

- Absolute neutrophil count (ANC) < 1000/mL at baseline

- Platelet count < 50,000/mL at baseline