active bacterial pneumonia infection known active tuberculosis (tb). history of child-pugh b or c cirrhosis. history of ischemic heart disease or myocardial infarction or acute coronary syndrome. subjects requiring supplemental oxygen ≥0.75 fio2. it is not in the best interest of the subjects to participate, in the opinion of the treating investigator. female subjects who are pregnant or breastfeeding or expecting to conceive within the projected duration of the study, starting with the screening visit through 90 days after the last dose of study drug. the following laboratory parameters are excluded: * alanine aminotransferase (alt) or aspartate aminotransferase (ast) \>5 x upper limit of normal (uln); * creatinine clearance \< 50 ml/min. requiring, or expected to require mechanical ventilation at screening. treatment with chloroquine or hydroxychloroquine at study entry. treatment with anti-il 6, anti-il-6 receptor antagonists, or with janus kinase inhibitors (jaki) in the past 30 days or plans to receive during the study period. participation in any other clinical study of an experimental drug treatment for covid-19 within 6 half-lives of the experimental treatment. note: subjects participating in an observational study are an exception to this criterion and may qualify for the study with sponsor approval. note: subjects who have entered the follow-up phase of an investigational study may participate as long as it has been 4 weeks after the last dose of the previous investigational agent. * unable to swallow solid oral medication or known malabsorption disorder. * subjects who have allergy to bld-2660 or inactive components of bld-2660.

active bacterial pneumonia infection known active tuberculosis (tb). history of child-pugh b or c cirrhosis. history of ischemic heart disease or myocardial infarction or acute coronary syndrome. subjects requiring supplemental oxygen ≥0.75 fio2. it is not in the best interest of the subjects to participate, in the opinion of the treating investigator. female subjects who are pregnant or breastfeeding or expecting to conceive within the projected duration of the study, starting with the screening visit through 90 days after the last dose of study drug. the following laboratory parameters are excluded: * alanine aminotransferase (alt) or aspartate aminotransferase (ast) \>5 x upper limit of normal (uln); * creatinine clearance \< 50 ml/min. requiring, or expected to require mechanical ventilation at screening. treatment with chloroquine or hydroxychloroquine at study entry. treatment with anti-il 6, anti-il-6 receptor antagonists, or with janus kinase inhibitors (jaki) in the past 30 days or plans to receive during the study period. participation in any other clinical study of an experimental drug treatment for covid-19 within 6 half-lives of the experimental treatment. note: subjects participating in an observational study are an exception to this criterion and may qualify for the study with sponsor approval. note: subjects who have entered the follow-up phase of an investigational study may participate as long as it has been 4 weeks after the last dose of the previous investigational agent. * unable to swallow solid oral medication or known malabsorption disorder. * subjects who have allergy to bld-2660 or inactive components of bld-2660.

active bacterial pneumonia infection known active tuberculosis (tb). history of child-pugh b or c cirrhosis. history of ischemic heart disease or myocardial infarction or acute coronary syndrome. subjects requiring supplemental oxygen ≥0.75 fio2. it is not in the best interest of the subjects to participate, in the opinion of the treating investigator. female subjects who are pregnant or breastfeeding or expecting to conceive within the projected duration of the study, starting with the screening visit through 90 days after the last dose of study drug. the following laboratory parameters are excluded: - alanine aminotransferase (alt) or aspartate aminotransferase (ast) >5 x upper limit of normal (uln); - creatinine clearance < 50 ml/min. requiring, or expected to require mechanical ventilation at screening. treatment with chloroquine or hydroxychloroquine at study entry. treatment with anti-il 6, anti-il-6 receptor antagonists, or with janus kinase inhibitors (jaki) in the past 30 days or plans to receive during the study period. participation in any other clinical study of an experimental drug treatment for covid-19 within 6 half-lives of the experimental treatment. note: subjects participating in an observational study are an exception to this criterion and may qualify for the study with sponsor approval. note: subjects who have entered the follow-up phase of an investigational study may participate as long as it has been 4 weeks after the last dose of the previous investigational agent. - unable to swallow solid oral medication or known malabsorption disorder. - subjects who have allergy to bld-2660 or inactive components of bld-2660.

active bacterial pneumonia infection known active tuberculosis (tb). history of child-pugh b or c cirrhosis. history of ischemic heart disease or myocardial infarction or acute coronary syndrome. subjects requiring supplemental oxygen ≥0.75 fio2. it is not in the best interest of the subjects to participate, in the opinion of the treating investigator. female subjects who are pregnant or breastfeeding or expecting to conceive within the projected duration of the study, starting with the screening visit through 90 days after the last dose of study drug. the following laboratory parameters are excluded: - alanine aminotransferase (alt) or aspartate aminotransferase (ast) >5 x upper limit of normal (uln); - creatinine clearance < 50 ml/min. requiring, or expected to require mechanical ventilation at screening. treatment with chloroquine or hydroxychloroquine at study entry. treatment with anti-il 6, anti-il-6 receptor antagonists, or with janus kinase inhibitors (jaki) in the past 30 days or plans to receive during the study period. participation in any other clinical study of an experimental drug treatment for covid-19 within 6 half-lives of the experimental treatment. note: subjects participating in an observational study are an exception to this criterion and may qualify for the study with sponsor approval. note: subjects who have entered the follow-up phase of an investigational study may participate as long as it has been 4 weeks after the last dose of the previous investigational agent. - unable to swallow solid oral medication or known malabsorption disorder. - subjects who have allergy to bld-2660 or inactive components of bld-2660.