Can existing drugs stop COVID-19 from getting worse?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Patients age ≥ 18 years at screening * Patients with mild or moderate C19 pneumonia, defined as Grade 3 or 4 severity by the WHO COVID-19 Ordinal Scale by * Patients meeting criteria: Hospitalization AND SARS-CoV2 infection (clinically suspected\* or laboratory-confirmed) AND Radiological change consistent with COVID-19 disease * C-reactive protein (CRP) greater than or equal to 30mg/L * Informed consent from patient or personal or professional representative * No medical history that might, in the opinion of the responsible clinician, put the patient at significant risk if he/she were to participate in the trial * Agreement to abstain from sexual intercourse or use contraception that is \>99% effective for all participants of childbearing potential for 42 days after the last dose of study drug. For male participants, agreement to abstain from sperm donation for 42 days after the last dose of study drug. * Able to read English. Non-English speakers will be able to join the study. If patients are unable to understand verbal or written information in English - hospital translation services will be requested at the participating site for the participant where possible. Exclusion Criteria: * Requiring either invasive or non-invasive ventilation including CPAP or high flow nasal oxygen at any point after hospital admission and before baseline not related to a pre-existing condition (e.g. obstructive sleep apnoea) * Grade ≥ 5 severity on the modified WHO COVID-19 Ordinal Scale, viz. O2 saturation \< 90% on ≥ 60% inspired oxygen at baseline; non-invasive ventilation; or invasive mechanical ventilation at any point since hospital admission. * In the opinion of the investigator, progression to death is inevitable within the next 24 hours, irrespective of the provision of therapy * Known severe allergic reactions to the investigational agents * Child Pugh B or C grade hepatic dysfunction * Use of drugs within the preceding 14 days that are known to interact with any study treatment (FOS or RUX), as listed in the Summary of Product Characteristics * Pregnant or breast feeding * Any medical condition or concomitant medication that in the opinion of the investigator would compromise subjects' safety or compliance with study procedures. * Any medical condition which in the opinion of the principal investigator would compromise the scientific integrity of the study * Pregnant or breast feeding