A Study to Evaluate the Safety and Efficacy of Tocilizumab in Patients With Severe COVID-19 Pneumonia

Inclusion Criteria:

* Hospitalized with COVID-19 pneumonia confirmed per WHO criteria (including a positive PCR of any specimen; e.g., respiratory, blood, urine, stool, other bodily fluid) and evidenced by chest X-ray or CT scan
* SPO2 \
Exclusion Criteria:

* Known severe allergic reactions to TCZ or other monoclonal antibodies
* Active tuberculosis (TB) infection
* 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 TCZ) with the past 3 months
* Participating in other drug clinical trials (participation in COVID-19 anti-viral trials may be permitted if approved by Medical Monitor)
* Pregnant or breastfeeding, or positive pregnancy test in a pre-dose examination
* Treatment with an investigational drug within 5 half-lives or 30 days (whichever is longer) of randomization (investigational COVID-19 antivirals may be permitted if approved by Medial Monitor)
* 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 screening (per local lab)
* Absolute neutrophil count (ANC) \< 1000/mL at screening (per local lab)
* Platelet count \< 50,000/mL at screening (per local lab)