ABSTRACT
Granulocyte-macrophage colony-stimulating factor (GM-CSF) plays a central role in immune response;it is a key mediator of inflammation and tissue injury. Lenzilumab, a humanized anti-GM-CSF monoclonal antibody directly binds to GM-CSF and prevents signaling through its receptor;it is being eval-uated for its efficacy and safety in treating COVID-19 as well as several inflammatory and autoimmune conditions. The purpose of this review was to summarize available data on the clinical safety and efficacy of lenzilumab for the treat- ment of inflammatory and autoimmune diseases as well as COVID-19. In a phase II study of patients with chronic myelo- monocytic leukemia, lenzilumab was associated with a dura- ble clinical benefit in a third of participants. In patients with inadequately controlled asthma, lenzilumab improved FEV1 in eosinophilic asthmatics, but did not improve asthma con-trol. In patients with severe COVID-19 pneumonia, lenzilu-mab significantly improved survival without ventilation over and above current supportive treatments, including remde-sivir and corticosteroids. Among these patients, those with baseline C-reactive protein (CRP) values less than 150 mg/L derived the greatest benefit from lenzilumab. Lenzilumab was safe and well tolerated. In the clinical trials conducted to date, no deaths, drug-related serious adverse events or withdraw- als due to adverse events were noted.