The study is a double-blind, randomized, placebo-controlled, multi-center, Phase 3 study to evaluate the efficacy and safety of fostamatinib in COVID-19 subjects.

The primary objective of this study is:

To evaluate the efficacy of fostamatinib when used in combination with standard of care (SOC) in subjects hospitalized with COVID- 19 and requiring oxygen supplementation, as measured by days on oxygen.

Inclusion Criteria:

• ≥18 years of age at screening.
• The subject or a legally authorized representative has provided written informed consent.
• Hospitalized COVID-19 subjects without respiratory failure who are either not receiving any oxygen therapy or are receiving supplemental oxygen via mask or nasal prongs.
• Male or non-pregnant, non-lactating female subjects with SARS-CoV-2 infection documented by a hospital approved diagnostic test (eg, a Food and Drug Administration authorized test in the US) within 7 days prior to randomization.

Exclusion Criteria:

• Pregnant or lactating female of childbearing potential.
• Use of extracorporeal membrane oxygenation (ECMO).
• Uncontrolled hypertension (systolic blood pressure [BP] ≥160 mmHg and/or diastolic BP ≥100 mmHg), unstable angina, congestive heart failure of New York Heart Association classification III or IV, serious cardiac arrhythmia requiring treatment at screening.
• History of myocardial infarction within 1 month prior to screening.