None

None

1. participation in any other clinical trial of an experimental treatment for covid-19 (remdesivir and convalescent plasma use is permitted). 2. subject has clinically significant history or evidence of cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, neurological, immunological or psychiatric disorder(s) as determined by the pi or designee. 3. concurrent treatment with other agents with actual or possible direct acting immunomodulatory activity against ards in covid-19 is prohibited <72 hours prior to study drug dosing [il-6 inhibitors such as sarilumab and tocilizumab; il-1β blocker; and the jak1/jak2 inhibitor ruxolitinib, barcitinib and tofacitinib; complement inhibitor ravulizumab-cwvz; bruton's tyrosine kinase inhibitor acalabrutinib, and macrophage migration inhibitor ibudilast]. 4. history of splenomegaly (spleen weighing >750 g). 5. history of cancer or thrombocytopenia (platelet count <100,000/µl) or thrombocythemia (platelet count >500,000/µl). 6. known family history of long qt syndrome (torsades de pointes) or currently taking medication that prolongs qt interval. 7. currently taking immunomodulating biologics (e.g, interferons, interleukin). 8. female subjects who are pregnant or breastfeeding or planning to breastfeed at any time through 90 days after last dose of study drug. 9. any disorder that would interfere with the absorption, distribution, metabolism or excretion of drugs. 10. received a vaccination (including influenza) administered 30 days or less prior to first treatment/randomization or has any planned vaccinations during the treatment period. 11. creatinine clearance <50 ml/min using the cockcroft-gault formula. 12. has the following liver function levels: serum alp or bil >1.5 uln or alt or ast >uln (part a); serum alp or bil >3.0 uln or alt or ast >5.0x uln (part b); at either screening or admission. only 1 repeat assessment is allowed on each occasion. 13. history of alcohol and/or illicit drug abuse within 2 years of entry. 14. positive test for hepatitis b surface antigen (hbsag), hepatitis c antibody, or hiv antibody. 15. has a positive blood test for ethanol at the screening visit or admission. 16. has a positive urine drug test (e.g., cocaine, amphetamines, barbiturates, opiates, benzodiazepines, cannabinoids) at the screening visit or admission. 17. has donated blood (>500 ml) or blood products within 2 months (56 days) prior to admission. 18. has used an investigational drug within 30 days prior to screening. 19. history of hypersensitivity to mrg-001 (plerixafor [amd3100, 24 mg/ml]) and tacrolimus [fk506, 0.5 mg/ml]) or any of the excipients or to medicinal products with similar chemical structures. 20. unable to understand the protocol requirements, instructions and study related restrictions, the nature, scope and possible consequences of the clinical study. 21. unlikely to comply with the protocol requirements, instructions and study related restrictions; e.g., uncooperative attitude, inability to return for follow-up visits and improbability of completing the clinical study. 22. previously been enrolled in this clinical study. 23. vulnerable subjects defined as individuals whose willingness to volunteer in a clinical study may be unduly influenced by the expectation, whether justified or not, of benefits associated with participation, or of a retaliatory response from senior members of a hierarchy in case of refusal to participate (e.g., persons in detention, minors and those incapable of giving consent). 24. laboratory-confirmation of sars-cov-2 by real time polymerase chain reaction in the respiratory tract (np swab, tracheal aspirate, bal) ≤96 hours prior to randomization. 25. is unwilling to avoid use of alcohol or alcohol-containing foods, medications or beverages, within 48 hours prior to screening until discharge from the clinical site. 26. is unable to abstain from smoking (or other nicotine use) from screening until discharge from the clinical site. 27. has any concurrent disease or condition that, in the opinion of the pi, would make the subject unsuitable for participation in the clinical study such as: 1. skin condition or disease (e.g., stevens-johnson syndrome). 2. hypertension defined as >140 mmhg systolic blood pressure and >95 mmhg diastolic blood pressure. 3. high blood potassium (hyperkalemia) defined baseline serum potassium >5.0 to 5.5 meq/l (milliequivalent). 4. torsades de pointes or currently taking medication that prolongs qt interval. 5. hematologic disorder (e.g. anemia or leukemia). 6. type i or type 2 diabetes mellitus defined as a fasting blood glucose level >126 mg/dl (7.0 mmol/l).

1. participation in any other clinical trial of an experimental treatment for covid-19 (remdesivir and convalescent plasma use is permitted). 2. subject has clinically significant history or evidence of cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, neurological, immunological or psychiatric disorder(s) as determined by the pi or designee. 3. concurrent treatment with other agents with actual or possible direct acting immunomodulatory activity against ards in covid-19 is prohibited <72 hours prior to study drug dosing [il-6 inhibitors such as sarilumab and tocilizumab; il-1β blocker; and the jak1/jak2 inhibitor ruxolitinib, barcitinib and tofacitinib; complement inhibitor ravulizumab-cwvz; bruton's tyrosine kinase inhibitor acalabrutinib, and macrophage migration inhibitor ibudilast]. 4. history of splenomegaly (spleen weighing >750 g). 5. history of cancer or thrombocytopenia (platelet count <100,000/µl) or thrombocythemia (platelet count >500,000/µl). 6. known family history of long qt syndrome (torsades de pointes) or currently taking medication that prolongs qt interval. 7. currently taking immunomodulating biologics (e.g, interferons, interleukin). 8. female subjects who are pregnant or breastfeeding or planning to breastfeed at any time through 90 days after last dose of study drug. 9. any disorder that would interfere with the absorption, distribution, metabolism or excretion of drugs. 10. received a vaccination (including influenza) administered 30 days or less prior to first treatment/randomization or has any planned vaccinations during the treatment period. 11. creatinine clearance <50 ml/min using the cockcroft-gault formula. 12. has the following liver function levels: serum alp or bil >1.5 uln or alt or ast >uln (part a); serum alp or bil >3.0 uln or alt or ast >5.0x uln (part b); at either screening or admission. only 1 repeat assessment is allowed on each occasion. 13. history of alcohol and/or illicit drug abuse within 2 years of entry. 14. positive test for hepatitis b surface antigen (hbsag), hepatitis c antibody, or hiv antibody. 15. has a positive blood test for ethanol at the screening visit or admission. 16. has a positive urine drug test (e.g., cocaine, amphetamines, barbiturates, opiates, benzodiazepines, cannabinoids) at the screening visit or admission. 17. has donated blood (>500 ml) or blood products within 2 months (56 days) prior to admission. 18. has used an investigational drug within 30 days prior to screening. 19. history of hypersensitivity to mrg-001 (plerixafor [amd3100, 24 mg/ml]) and tacrolimus [fk506, 0.5 mg/ml]) or any of the excipients or to medicinal products with similar chemical structures. 20. unable to understand the protocol requirements, instructions and study related restrictions, the nature, scope and possible consequences of the clinical study. 21. unlikely to comply with the protocol requirements, instructions and study related restrictions; e.g., uncooperative attitude, inability to return for follow-up visits and improbability of completing the clinical study. 22. previously been enrolled in this clinical study. 23. vulnerable subjects defined as individuals whose willingness to volunteer in a clinical study may be unduly influenced by the expectation, whether justified or not, of benefits associated with participation, or of a retaliatory response from senior members of a hierarchy in case of refusal to participate (e.g., persons in detention, minors and those incapable of giving consent). 24. laboratory-confirmation of sars-cov-2 by real time polymerase chain reaction in the respiratory tract (np swab, tracheal aspirate, bal) ≤96 hours prior to randomization. 25. is unwilling to avoid use of alcohol or alcohol-containing foods, medications or beverages, within 48 hours prior to screening until discharge from the clinical site. 26. is unable to abstain from smoking (or other nicotine use) from screening until discharge from the clinical site. 27. has any concurrent disease or condition that, in the opinion of the pi, would make the subject unsuitable for participation in the clinical study such as: 1. skin condition or disease (e.g., stevens-johnson syndrome). 2. hypertension defined as >140 mmhg systolic blood pressure and >95 mmhg diastolic blood pressure. 3. high blood potassium (hyperkalemia) defined baseline serum potassium >5.0 to 5.5 meq/l (milliequivalent). 4. torsades de pointes or currently taking medication that prolongs qt interval. 5. hematologic disorder (e.g. anemia or leukemia). 6. type i or type 2 diabetes mellitus defined as a fasting blood glucose level >126 mg/dl (7.0 mmol/l).

1. participation in any other clinical trial of an experimental treatment for covid-19 (remdesivir and convalescent plasma use is permitted). 2. subject has clinically significant history or evidence of cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, neurological, immunological or psychiatric disorder(s) as determined by the principal investigator or designee. 3. concurrent treatment with other agents with actual or possible direct acting immunomodulatory activity against ards in covid-19 is prohibited <72 hours prior to study drug dosing [il-6 inhibitors such as sarilumab and tocilizumab; il-1β blocker; and the jak1/jak2 inhibitor ruxolitinib, barcitinib and tofacitinib; complement inhibitor ravulizumab-cwvz; bruton's tyrosine kinase inhibitor acalabrutinib, and macrophage migration inhibitor ibudilast]. 4. history of splenomegaly (spleen weighing >750 g). 5. history of cancer or thrombocytopenia (platelet count <100,000/µl) or thrombocythemia (platelet count >500,000/µl). 6. known family history of long qt syndrome (torsades de pointes) or currently taking medication that prolongs qt interval. 7. currently taking immunomodulating biologics (e.g, interferons, interleukin). 8. female subjects who are pregnant or breastfeeding or planning to breastfeed at any time through 90 days after last dose of ip. 9. any disorder that would interfere with the absorption, distribution, metabolism or excretion of drugs. 10. received a vaccination (including influenza) administered 30 days or less prior to first treatment/randomization or has any planned vaccinations during the treatment period. 11. creatinine clearance <50 ml/min using the cockcroft-gault formula. 12. has the following liver function levels: serum alp or bil >1.5 uln or alt or ast >uln (part a); serum alp or bil >3.0 uln or alt or ast >5.0x uln (part b); at either screening or admission. only 1 repeat assessment is allowed on each occasion. 13. history of alcohol and/or illicit drug abuse within 2 years of entry. 14. positive test for hepatitis b surface antigen (hbsag), hepatitis c antibody or human immunodeficiency virus (hiv) antibody. 15. has a positive blood test for ethanol at the screening visit or admission. 16. has a positive urine drug test (e.g., cocaine, amphetamines, barbiturates, opiates, benzodiazepines, cannabinoids) at the screening visit or admission. 17. has donated blood (>500 ml) or blood products within 2 months (56 days) prior to admission. 18. has used an investigational drug within 30 days prior to screening. 19. history of hypersensitivity to mrg-001 (plerixafor [amd3100, 24 mg/ml]) and tacrolimus [fk506, 0.5 mg/ml]) or any of the excipients or to medicinal products with similar chemical structures. 20. unable to understand the protocol requirements, instructions and study related restrictions, the nature, scope and possible consequences of the clinical study. 21. unlikely to comply with the protocol requirements, instructions and study related restrictions; e.g., uncooperative attitude, inability to return for follow-up visits and improbability of completing the clinical study. 22. previously been enrolled in this clinical study. 23. vulnerable subjects defined as individuals whose willingness to volunteer in a clinical study may be unduly influenced by the expectation, whether justified or not, of benefits associated with participation, or of a retaliatory response from senior members of a hierarchy in case of refusal to participate (e.g., persons in detention, minors and those incapable of giving consent). 24. moderate, severe, or critical covid-19 clinical status. 25. is unwilling to avoid use of alcohol or alcohol-containing foods, medications or beverages, within 48 hours prior to screening until discharge from the clinical site. 26. is unable to abstain from smoking (or other nicotine use) from screening until discharge from the clinical site. 27. has any concurrent disease or condition that, in the opinion of the principal investigator, would make the subject unsuitable for participation in the clinical study such as (part a only): 1. skin condition or disease (e.g., stevens-johnson syndrome). 2. hypertension defined as >140 mmhg systolic blood pressure and >95 mmhg diastolic blood pressure. 3. high blood potassium (hyperkalemia) defined baseline serum potassium >5.0 to 5.5 meq/l (milliequivalent). 4. concurrent active infection such as influenza. 5. torsades de pointes or currently taking medication that prolongs qt interval. 6. hematologic disorder (e.g. anemia or leukemia). 7. type i or type 2 diabetes mellitus defined as a fasting blood glucose level >126 mg/dl (7.0 mmol/l).

1. participation in any other clinical trial of an experimental treatment for covid-19 (remdesivir and convalescent plasma use is permitted). 2. subject has clinically significant history or evidence of cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, neurological, immunological or psychiatric disorder(s) as determined by the principal investigator or designee. 3. concurrent treatment with other agents with actual or possible direct acting immunomodulatory activity against ards in covid-19 is prohibited <72 hours prior to study drug dosing [il-6 inhibitors such as sarilumab and tocilizumab; il-1β blocker; and the jak1/jak2 inhibitor ruxolitinib, barcitinib and tofacitinib; complement inhibitor ravulizumab-cwvz; bruton's tyrosine kinase inhibitor acalabrutinib, and macrophage migration inhibitor ibudilast]. 4. history of splenomegaly (spleen weighing >750 g). 5. history of cancer or thrombocytopenia (platelet count <100,000/µl) or thrombocythemia (platelet count >500,000/µl). 6. known family history of long qt syndrome (torsades de pointes) or currently taking medication that prolongs qt interval. 7. currently taking immunomodulating biologics (e.g, interferons, interleukin). 8. female subjects who are pregnant or breastfeeding or planning to breastfeed at any time through 90 days after last dose of ip. 9. any disorder that would interfere with the absorption, distribution, metabolism or excretion of drugs. 10. received a vaccination (including influenza) administered 30 days or less prior to first treatment/randomization or has any planned vaccinations during the treatment period. 11. creatinine clearance <50 ml/min using the cockcroft-gault formula. 12. has the following liver function levels: serum alp or bil >1.5 uln or alt or ast >uln (part a); serum alp or bil >3.0 uln or alt or ast >5.0x uln (part b); at either screening or admission. only 1 repeat assessment is allowed on each occasion. 13. history of alcohol and/or illicit drug abuse within 2 years of entry. 14. positive test for hepatitis b surface antigen (hbsag), hepatitis c antibody or human immunodeficiency virus (hiv) antibody. 15. has a positive blood test for ethanol at the screening visit or admission. 16. has a positive urine drug test (e.g., cocaine, amphetamines, barbiturates, opiates, benzodiazepines, cannabinoids) at the screening visit or admission. 17. has donated blood (>500 ml) or blood products within 2 months (56 days) prior to admission. 18. has used an investigational drug within 30 days prior to screening. 19. history of hypersensitivity to mrg-001 (plerixafor [amd3100, 24 mg/ml]) and tacrolimus [fk506, 0.5 mg/ml]) or any of the excipients or to medicinal products with similar chemical structures. 20. unable to understand the protocol requirements, instructions and study related restrictions, the nature, scope and possible consequences of the clinical study. 21. unlikely to comply with the protocol requirements, instructions and study related restrictions; e.g., uncooperative attitude, inability to return for follow-up visits and improbability of completing the clinical study. 22. previously been enrolled in this clinical study. 23. vulnerable subjects defined as individuals whose willingness to volunteer in a clinical study may be unduly influenced by the expectation, whether justified or not, of benefits associated with participation, or of a retaliatory response from senior members of a hierarchy in case of refusal to participate (e.g., persons in detention, minors and those incapable of giving consent). 24. moderate, severe, or critical covid-19 clinical status. 25. is unwilling to avoid use of alcohol or alcohol-containing foods, medications or beverages, within 48 hours prior to screening until discharge from the clinical site. 26. is unable to abstain from smoking (or other nicotine use) from screening until discharge from the clinical site. 27. has any concurrent disease or condition that, in the opinion of the principal investigator, would make the subject unsuitable for participation in the clinical study such as (part a only): 1. skin condition or disease (e.g., stevens-johnson syndrome). 2. hypertension defined as >140 mmhg systolic blood pressure and >95 mmhg diastolic blood pressure. 3. high blood potassium (hyperkalemia) defined baseline serum potassium >5.0 to 5.5 meq/l (milliequivalent). 4. concurrent active infection such as influenza. 5. torsades de pointes or currently taking medication that prolongs qt interval. 6. hematologic disorder (e.g. anemia or leukemia). 7. type i or type 2 diabetes mellitus defined as a fasting blood glucose level >126 mg/dl (7.0 mmol/l).