On Sept. 2, 2020, Mesoblast announced that it had received ethics approval to include Australian hospitals in the Phase 3 randomized controlled trial of remestemcel-L in ventilator-dependent COVID-19 patients with acute respiratory distress syndrome (ARDS).

Participating hospitals in Melbourne and Sydney have been granted approval by the Human Research Ethics Committee of Monash Health and will join more than 17 leading US medical centers already in the Phase 3 trial. This study is being conducted by the US National Institutes of Health–funded Cardiothoracic Surgical Trials Network, and cleared by the US Food and Drug Administration (FDA).

The clinical protocol evaluating remestemcel-L in up to 300 patients in the Phase 3 trial was based on results from a pilot study using remestemcel-L under emergency compassionate care at Mt Sinai Hospital in New York, with 75% (nine of 12) of patients with moderate to severe ARDS successfully taken off a ventilator and discharged from hospital within a median of 10 days. The Phase 3 trial is enrolling ventilator-dependent patients in intensive care units with moderate to severe COVID-19 ARDS randomized (1:1) to receive either two intravenous infusions of remestemcel-L three to five days apart or placebo on top of maximal care. The primary endpoint is all-cause mortality within 30 days of randomization, with the key secondary endpoint being the number of days off mechanical ventilator support.