The US Food and Drug Administration (FDA) has granted Fast Track designation for remestemcel-L in the treatment of acute respiratory distress syndrome (ARDS) due to COVID-19 infection. The designation was given because remestemcel-L has shown the potential to combat the primary cause of death in patients with COVID-19 – ARDS.

Fast Track designation is intended to facilitate the development and expedite the review of therapies to treat serious and life-threatening conditions with no or limited treatment options. Under Fast Track designation, a Biologic License Application (BLA) for remestemcel-L is eligible for both rolling submission and priority review.

According to Mesoblast Limited (the developer of remestemcel-L), the designation was based on data from a pilot study in which remestemcel-L was administered under emergency compassionate use in March-April this year. In this study, nine of 12 ventilator-dependent patients (75 percent) with moderate to severe COVID-19 ARDS were successfully discharged from hospital a median of 10 days after receiving two intravenous doses of remestemcel-L.

Remestemcel-L is currently being evaluated in an ongoing randomised Phase III trial of in up to 300 ventilator-dependent patients with moderate to severe COVID-19 ARDS. The trial is approximately 60 percent enrolled and has been advised to continue after two interim analyses performed by the independent Data Safety Monitoring Board (DSMB) – after 90 and 135 patients were enrolled. The trial’s primary endpoint is overall mortality at Day 30 and the key secondary endpoint is days alive off ventilatory support through Day 60. A final interim analysis is planned for when 180 patients have completed 30 days of follow-up.

COVID-19-related ARDS is thought to be caused by a dysregulated immune response in the lungs to the SARS-CoV-2 virus, which causes COVID-19. Despite improved treatment and earlier intervention in hospitalised COVID-19 patients overall, the mortality rate in COVID-19 ARDS patients who are over 60 years old remains more than 60 percent and deaths in ventilator-dependent ARDS patients continue to rise.