Both lenzilumab Covid trials were for severe patients. No moderates or criticals in either trial.
You are correct about moderates in the Activ-5 trial but not about critical. With lenzilumab showing benefit in CRP < 150 which shows the start of severe illness those 6 and 7s on the ordinal scale will destroy the p value.
Avtiv-5 inclusion criteria : Illness of any duration, and requiring, just prior to randomization, supplemental oxygen (any flow), mechanical ventilation or Extracorporeal Membrane Oxygenation (ECMO) (ordinal score 5, 6, or 7). https://www.clinicaltrials.gov/ct2/show/NCT04583969
Looking at the full data I did notice that there were 4.7% less patients on High Flow Oxygen or NPPV in the leronlimab arm. Also there were 4.1% more patients with CRP < 150 in the placebo arm. So you have more placebo patients in worse condition and more with a lower CRP. Which could definitely skew results by looking at CRP < 150 as the basis of analysis. No wonder the FDA rejected the EUA.