Leronlimab in Patients With Coronavirus Disease 2019 (COVID-19) With Need for Mechanical Ventilation or Extracorporeal Membrane Oxygenation

Leronlimab (PRO 140) is a humanized IgG4,k monoclonal antibody (mAb) that recognizes the C-C chemokine receptor type 5 (CCR5). CCR5 is expressed predominantly on T cells but also found on macrophages, dendritic cells, and eosinophils to mediate chemotaxis in response to its cognate ligands that include CCL5 (RANTES), CCL3 (MIP-1α), and CCL4 (MIP-1β). These ligands are integral in the recruitment of these immune cells to inflammatory sites. The immunopathogenesis of COVID-19 likely involves the excessive influx of immune cells into the lung. Disruption of the CCL5-CCR5 axis via leronlimab-mediated CCR5 blockade might prevent pulmonary trafficking of pro-inflammatory leukocytes and dampen pathogenic immune activation in COVID-19. The purpose of the study is to assess the safety and efficacy of leronlimab plus standard of care in critically ill patients hospitalized with COVID-19 pneumonia who are requiring mechanical ventilation or extracorporeal oxigenation (ECMO). This is a Phase 3, 2-arm, randomized, double blind, placebo controlled, multicenter study to evaluate the safety and efficacy of leronlimab (PRO 140) as an add on therapy to the institutional standard of care (SoC) for the management of critically ill patients with COVID-19 pneumonia. Patients will be randomized in a 1:1 ratio to receive up to four doses of 700 mg leronlimab (PRO 140) or placebo. Leronlimab or placebo will be administered by 30-minute intravenous (IV) infusion weekly over a 4-week treatment period. No treatments will be administered post-discharge. The participant will be evaluated on each study day while hospitalized up until and including Day 28. The daily visits will capture clinical status - ordinal scale and the occurrence of adverse events. A complete follow-up assessment will be performed at Days 7, 14, 21, 28, 42 and 60 for those who are hospitalized at these specific timepoints. Follow-up visits can be conducted as telephone or video contact visits, if subject is discharged from the hospital prior to the complete follow-up visits.