C3 and acute respiratory distress syndrome: The C3 inhibitor AMY-101 resulted in successful treatment of a patient with severe ARDS due to COVID-19 pneumonia [91] and is being investigated for the management of ARDS caused by COVID-19 in a Phase 2 placebo-controlled trial [96], although a Phase 1/2 trial of the C3 inhibitor APL-9, a pegylated form of AMY-101, for the treatment of severe COVID-19 was recently discontinued due to lack of efficacy [97].