1. aspartate aminotransferase (ast) or alanine aminotransferase (alt) \> 5 times the upper limit of normal. 2. subjects with a low glomerular filtration rate (egfr), specifically: 1. subjects with an egfr 15-30 ml/min are excluded unless in the opinion of the principal investigator (pi), the potential benefit of participation outweighs the potential risk of study participation. 2. all subjects with an egfr \<15 ml/min (including hemodialysis and hemofiltration) are excluded. 3. pregnancy or breast feeding 4. anticipated discharge from the hospital or transfer to another hospital which is not a study site within 72 hours of enrollment. 5. allergy to any study medication. 6. received five or more doses of remdesivir prior to screening. 7. treatment with a complement inhibitor in the prior 8 weeks.\* 8. has active uncontrolled opportunistic infection, or uncontrolled cirrhosis.\* 9. history of infection with n. meningitidis.\* 10. known history of hypersensitivity to danicopan or its excipients.\* 11. has a medical condition that could, in the judgment of the investigator, limit the interpretation and generalizability of trial results. 12. positive test for influenza virus during the current illness (influenza testing is not required by protocol). 13. history of liver cirrhosis.\* 14. previous participation in an activ-5/bet trial. 15. refuses to refrain from breastfeeding from the time of screening through 30 days after the last dose of danicopan.\* 16. refuses to receive prophylactic antibiotics against meningococcal infections if the subject has not been vaccinated in the 3 years prior to study day 1.

1. aspartate aminotransferase (ast) or alanine aminotransferase (alt) \> 5 times the upper limit of normal. 2. subjects with a low glomerular filtration rate (egfr), specifically: 1. subjects with an egfr 15-30 ml/min are excluded unless in the opinion of the principal investigator (pi), the potential benefit of participation outweighs the potential risk of study participation. 2. all subjects with an egfr \<15 ml/min (including hemodialysis and hemofiltration) are excluded. 3. pregnancy or breast feeding 4. anticipated discharge from the hospital or transfer to another hospital which is not a study site within 72 hours of enrollment. 5. allergy to any study medication. 6. received five or more doses of remdesivir prior to screening. 7. treatment with a complement inhibitor in the prior 8 weeks.\* 8. has active uncontrolled opportunistic infection, or uncontrolled cirrhosis.\* 9. history of infection with n. meningitidis.\* 10. known history of hypersensitivity to danicopan or its excipients.\* 11. has a medical condition that could, in the judgment of the investigator, limit the interpretation and generalizability of trial results. 12. positive test for influenza virus during the current illness (influenza testing is not required by protocol). 13. history of liver cirrhosis.\* 14. previous participation in an activ-5/bet trial. 15. refuses to refrain from breastfeeding from the time of screening through 30 days after the last dose of danicopan.\* 16. refuses to receive prophylactic antibiotics against meningococcal infections if the subject has not been vaccinated in the 3 years prior to study day 1.

aspartate aminotransferase (ast) or alanine aminotransferase (alt) > 5 times the upper limit of normal. subjects with a low glomerular filtration rate (egfr), specifically: subjects with an egfr 15-30 ml/min are excluded unless in the opinion of the principal investigator (pi), the potential benefit of participation outweighs the potential risk of study participation. all subjects with an egfr <15 ml/min (including hemodialysis and hemofiltration) are excluded. pregnancy or breast feeding anticipated discharge from the hospital or transfer to another hospital which is not a study site within 72 hours of enrollment. allergy to any study medication. received five or more doses of remdesivir prior to screening. treatment with a complement inhibitor in the prior 8 weeks.* has active uncontrolled opportunistic infection, or uncontrolled cirrhosis.* history of infection with n. meningitidis.* known history of hypersensitivity to danicopan or its excipients.* has a medical condition that could, in the judgment of the investigator, limit the interpretation and generalizability of trial results. positive test for influenza virus during the current illness (influenza testing is not required by protocol). history of liver cirrhosis.* previous participation in an activ-5/bet trial. refuses to refrain from breastfeeding from the time of screening through 30 days after the last dose of danicopan.* refuses to receive prophylactic antibiotics against meningococcal infections if the subject has not been vaccinated in the 3 years prior to study day 1.

aspartate aminotransferase (ast) or alanine aminotransferase (alt) > 5 times the upper limit of normal. subjects with a low glomerular filtration rate (egfr), specifically: subjects with an egfr 15-30 ml/min are excluded unless in the opinion of the principal investigator (pi), the potential benefit of participation outweighs the potential risk of study participation. all subjects with an egfr <15 ml/min (including hemodialysis and hemofiltration) are excluded. pregnancy or breast feeding anticipated discharge from the hospital or transfer to another hospital which is not a study site within 72 hours of enrollment. allergy to any study medication. received five or more doses of remdesivir prior to screening. treatment with a complement inhibitor in the prior 8 weeks.* has active uncontrolled opportunistic infection, or uncontrolled cirrhosis.* history of infection with n. meningitidis.* known history of hypersensitivity to danicopan or its excipients.* has a medical condition that could, in the judgment of the investigator, limit the interpretation and generalizability of trial results. positive test for influenza virus during the current illness (influenza testing is not required by protocol). history of liver cirrhosis.* previous participation in an activ-5/bet trial. refuses to refrain from breastfeeding from the time of screening through 30 days after the last dose of danicopan.* refuses to receive prophylactic antibiotics against meningococcal infections if the subject has not been vaccinated in the 3 years prior to study day 1.

1. aspartate aminotransferase (ast) or alanine aminotransferase (alt) > 5 times the upper limit of normal. 2. subjects with a low glomerular filtration rate (egfr), specifically: 1. subjects with an egfr 15-30 ml/min are excluded unless in the opinion of the principal investigator (pi), the potential benefit of participation outweighs the potential risk of study participation. 2. all subjects with an egfr <15 ml/min (including hemodialysis and hemofiltration) are excluded. 3. pregnancy or breast feeding 4. anticipated discharge from the hospital or transfer to another hospital which is not a study site within 72 hours of enrollment. 5. allergy to any study medication. 6. received five or more doses of remdesivir prior to screening. 7. treatment with a complement inhibitor in the prior 8 weeks.* 8. has active uncontrolled opportunistic infection, or uncontrolled cirrhosis.* 9. history of infection with n. meningitidis.* 10. known history of hypersensitivity to danicopan or its excipients.* 11. has a medical condition that could, in the judgment of the investigator, limit the interpretation and generalizability of trial results. 12. positive test for influenza virus during the current illness (influenza testing is not required by protocol). 13. history of liver cirrhosis.* 14. previous participation in an activ-5/bet trial. 15. refuses to refrain from breastfeeding from the time of screening through 30 days after the last dose of danicopan.* 16. refuses to receive prophylactic antibiotics against meningococcal infections if the subject has not been vaccinated in the 3 years prior to study day 1.

1. aspartate aminotransferase (ast) or alanine aminotransferase (alt) > 5 times the upper limit of normal. 2. subjects with a low glomerular filtration rate (egfr), specifically: 1. subjects with an egfr 15-30 ml/min are excluded unless in the opinion of the principal investigator (pi), the potential benefit of participation outweighs the potential risk of study participation. 2. all subjects with an egfr <15 ml/min (including hemodialysis and hemofiltration) are excluded. 3. pregnancy or breast feeding 4. anticipated discharge from the hospital or transfer to another hospital which is not a study site within 72 hours of enrollment. 5. allergy to any study medication. 6. received five or more doses of remdesivir prior to screening. 7. treatment with a complement inhibitor in the prior 8 weeks.* 8. has active uncontrolled opportunistic infection, or uncontrolled cirrhosis.* 9. history of infection with n. meningitidis.* 10. known history of hypersensitivity to danicopan or its excipients.* 11. has a medical condition that could, in the judgment of the investigator, limit the interpretation and generalizability of trial results. 12. positive test for influenza virus during the current illness (influenza testing is not required by protocol). 13. history of liver cirrhosis.* 14. previous participation in an activ-5/bet trial. 15. refuses to refrain from breastfeeding from the time of screening through 30 days after the last dose of danicopan.* 16. refuses to receive prophylactic antibiotics against meningococcal infections if the subject has not been vaccinated in the 3 years prior to study day 1.