FDA determined it couldn’t conclude that the benefits of lenzilumab from Humanigen (NSDQ:HGEN) outweigh the risks for patients hospitalized with COVID-19.  Lenzilumab is the company’s lead product candidate.  The drug works by neutralizing granulocyte-macrophage colony-stimulating factor (GM-CSF), which is implicated in the so-called cytokine storm.  The drug is the subject of 16 clinical trials spanning…