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 higher than 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) higher than 5 x upper limit of normal (ULN), creatinine clearance lower than 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. Current participation or have participated in a study of an investigational agent or has used an investigational device within 4 weeks prior to the first dose of study drug. 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 higher than 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) higher than 5 x upper limit of normal (ULN), creatinine clearance lower than 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. Current participation or have participated in a study of an investigational agent or has used an investigational device within 4 weeks prior to the first dose of study drug. Unable to swallow solid oral medication or known malabsorption disorder. Subjects who have allergy to BLD-2660 or inactive components of BLD-2660