CRISIS2: A Phase 2 Study of the Safety and Antiviral Activity of Brequinar in Non-hospitalized Pts With COVID-19

Inclusion Criteria: 1. Willing and able to provide informed consent for the trial, written, electronic, verbal or other method deemed acceptable by the institution and IRB. 2. 18 years of age or older. 3. Laboratory-confirmed SARS-CoV-2 infection as determined by real time polymerase chain reaction (RT-PCR) or other FDA-approved commercial or public health assay. 4. Out-patient (never hospitalized as an in-patient for COVID-19 or was evaluated/treated for COVID-19 only in the Emergency Room with a stay of \< 24 hours) 5. The effects of brequinar on the developing human fetus are unknown. For this reason, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately. Men and women treated or enrolled on this protocol must also agree to use adequate contraception for the duration of study participation, and for 90 days after completion of brequinar administration. 6. Male subjects must agree to refrain from sperm donation and female subjects must agree to refrain from ovum donation from initial study drug administration until 90 days after the last dose of brequinar. 7. Must have at least one COVID-19 symptom including but not limited to fever, cough, sore throat, malaise, headache, muscle pain, gastrointestinal symptoms, shortness of breath, dyspnea, anosmia, dysgeusia, or other symptom commonly associated with COVID-19 in the opinion of the investigator. Symptom onset must be ≤7 days prior to first dose. Subject must have one or more symptoms at first dose. 8. Able to swallow capsules. Exclusion Criteria: 1. Any physical examination findings and/or history of any illness that, in the opinion of the study investigator, might confound the results of the study or pose an additional risk to the patient 2. Nursing women or women of childbearing potential (WOCBP) with a positive pregnancy test 3. Treatment with another DHODH inhibitor (e.g., leflunomide, teriflunomide) or other agents known to cause bone marrow suppression leading to thrombocytopenia 4. Platelets ≤150,000 cell/mm3 5. Hemoglobin \< 10 gm/dL 6. Absolute neutrophil count \< 1500 cells/mm3 7. Renal dysfunction, i.e., creatinine clearance \< 30 mL/min 8. AST or ALT \> 2 x ULN, or total bilirubin \> ULN. Gilbert's Syndrome is allowed. 9. Bleeding disorders or blood loss requiring transfusion in the six weeks preceding enrollment 10. Ongoing gastrointestinal ulcer, or gastrointestinal bleeding within 6 weeks of randomization. 11. Chronic hepatitis B infection, active hepatitis C infection, active liver disease and/or cirrhosis per subject report. 12. Heart failure, current uncontrolled cardiovascular disease, including unstable angina, uncontrolled arrhythmias, major adverse cardiac event within 6 months (e.g. stroke, myocardial infarction, hospitalization due to heart failure, or revascularization procedure).