Exosomes Derived from Bone Marrow Mesenchymal Stem Cells as Treatment for Severe COVID-19.

This prospective nonrandomized open-label cohort study addresses the safety and efficacy of exosomes (ExoFlo™) derived from allogeneic bone marrow mesenchymal stem cells as treatment for severe COVID-19. During April 2020, ExoFlo was provided to 24 SARS-CoV-2 polymerase chain reaction-positive patients at a single hospital center, all of whom met criteria for severe COVID-19 as well as moderate-to-severe acute respiratory distress syndrome. Patients received a single 15 mL intravenous dose of ExoFlo and were evaluated for both safety and efficacy from days 1 to 14 post-treatment.