This Phase 2b, multicenter, placebo-controlled, double-blind study will randomize approximately 500 adult patients who are symptomatic with mild or moderate COVID-19 (as defined in the FDA Guidance Document: Covid-19: Developing Drugs and Biological Products for Treatment or Prevention, May 2020) who are at high risk for progression to more severe disease. Patients will be randomized in a 1:1 ratio to inhaled sargramostim plus standard of care (SOC) or placebo plus SOC. Enrollment of patients who have completed a COVID-19 vaccination regimen or participated in a COVID-19 vaccine clinical trial will be capped at approximately 100 patients. All patients will be randomized to receive either 250 mcg of sargramostim or equivalent volume of placebo diluent. Treatment will be administered once daily for 5 days delivered via a vibrating mesh nebulizer. Patients will be followed for up to 60 days after start of treatment.~Sargramostim (Leukine) is a formulation of Granulocyte Macrophage Colony Stimulating Factor (GM-CSF), which is a critical cytokine for healthy pulmonary function. Detailed studies have shown that GM-CSF is necessary for alveolar macrophage (AM) maturation and maintenance. Although GM-CSF was discovered as a myelopoietic growth factor, it has diverse additional effects that both promote differentiation of myeloid precursors into neutrophils, monocytes, and dendritic cells and control function of mature myeloid cells. GM-CSF is also known to reverse immunoparalysis seen in sepsis, resulting in beneficial outcomes. In addition, GM-CSF prevents bacteremia in post influenza bacterial pneumonia through locally mediated improved lung antibacterial resistance and increased reactive oxygen species production by AMs. Pulmonary delivery of this GM-CSF has potential to reduce morbidity and mortality due to viral pneumonias, potentially including COVID-19.
The purpose of this research is to understand if the study drug, also called sargramostim or Leukine®, can help prevent the worsening of COVID-19 when the study drug is inhaled. This study will also help researchers understand if inhaled sargramostim can help prevent visits to the emergency room or hospitalization, or death.