Mesenchymal Stromal Cells For Acute Respiratory Distress Syndrome

This clinical study design is a randomized, double-blinded, placebo-controlled Phase 2b clinical trial using a 10 million cell/kg dose of human Mesenchymal Stromal Cells (hMSCs). Subjects will be randomized in a 1:1 randomization scheme to receive hMSCs or cell reconstitution media (1:1 mix of 5% human serum albumin and 10% Dextran 40) as the placebo; the study will enroll 120 patients who achieve a stable clinical baseline and receive study product (either hMSCs or the placebo). The Data and Safety Monitoring Board (DSMB) will review adverse outcomes and protocol compliance. A pre-specified interim review will occur after 60 subjects have been enrolled and received study product; enrollment will continue during the DSMB review. All pre-specified clinically important events and unexpected serious adverse events including death during hospitalization up to 60 days will be reported to the DSMB on an ongoing basis; the study will be stopped for a safety evaluation by the DSMB if they have any concerns or if three subjects have pre-specified clinically important events or unexpected serious adverse events except death since death will be common in this critically ill population due the nature of the underlying illness (e.g., ARDS).