@Anónimo both lenzilumab and mavrilimumab both GMCSF inhibitors trials are targeting patients with pneumonia but without full blown ARDS or mechanical vents. This gives insight into how the trials are designed in the context of MOA. A GMCSF inhibitor prevents stem cells from proliferating into additional immune cells. However, they will do nothing to prevent the migration of pre existing immune cells via RANTES.

In other words, these companies are not confident that GMCSF MOA will be effective past a certain therapeutic window of time.