Fostamatinib for Hospitalized Adults With COVID-19

Background: COVID-19 is a new disease caused by SARS-CoV-2 that was identified in 2019. Some people who get sick with COVID-19 become ill requiring hospitalization. There are some medicines that may help with recovery. Researchers want to see if a drug called fostamatinib may help people who are hospitalized with COVID-19. Objective: To learn if fostamatinib is safe in patients who are hospitalized with COVID-19 and gain earlier insight into whether it improves outcomes. Eligibility: Adults age 18 and older who are hospitalized with COVID-19. Design: Participants will be screened with a physical exam, including vital signs and weight. They will have a blood test and chest x-ray. They will have a COVID-19 test as a swab of either the back of the throat or the back of the nose. They will take a pregnancy test if needed. Participants will be randomly assigned, to take either fostamatinib pills or a placebo twice daily for up to 14 days in addition to standard of care for COVID-19. If they can swallow, they will take the pills by mouth with water. If they cannot swallow or are on mechanical ventilation, the pills will be crushed, mixed with water, and given through a tube placed through the nostril, or placed in the mouth, down the esophagus, and into the stomach. Blood samples will be taken daily. Participants will return to the Clinical Center for safety follow-up visits. At these visits, they will have a physical exam and blood tests. If they cannot visit the Clinical Center, they will be contacted by phone or have a telehealth visit. Participation will last for about two months