<h4>Background</h4>This study aimed to evaluate the safety and efficacy of inhaled pegylated adrenomedullin (PEG-ADM) for the management of acute respiratory distress syndrome in critically ill patients on mechanical ventilation.<h4>Methods</h4>A Phase 2a/b randomised, double-blind, placebo-controlled multicentre trial was conducted. This evidence concerns the gene ADM and acute respiratory distress syndrome.