On Dec. 9, 2021, CytoDyn announced that it had submitted a Phase 3, randomized, double blind, placebo controlled trial with the U.S. Food and Drug Administration to evaluate the efficacy and safety of leronlimab in combination with standard of care for critically ill patients with COVID-19 pneumonia with need for invasive mechanical ventilation or Extracorporeal Membrane Oxygenation.

The subgroup analyses of 62 critically ill patients in the past Phase 3 CD12 trial for severe-to-critically ill population in the U.S. showed an 82% survival benefit at Day 14 after two doses of leronlimab on Day 0 and Day 7 (Odd Ratio 0.09 (CI 0.01, 0.72), p-value 0.0233) vs. standard of care plus placebo. The survival benefit fell from 82% to 30% after four weeks.