This study is a multicenter, randomized, double-blinded, placebo-controlled trial to evaluate the safety and efficacy of ExoFlo for the treatment of moderate-to-severe ARDS (Acute Respiratory Distress Syndrome). The purpose of this study is to research and evaluate the safety and efficacy of intravenous (IV) administration of bone marrow mesenchymal stem cell derived extracellular vesicles, ExoFlo, as treatment for Moderate-to-Severe ARDS. Bone Marrow Mesenchymal Stem Cell (bmMSC)-Derived Extracellular Vesicles is an investigational drug created from human bone marrow being studied for the treatment of moderate-to-severe ARDS. This is a research study that will involve monitoring oxygen and inflammation levels after taking the investigational product and assessing the safety of the investigational product. The experimental treatment is a biologic product called Bone Marrow Mesenchymal Stem Cell (bmMSC)-Derived Extracellular Vesicles Allograft Product ExoFlo, which is purified from the bone marrow of a healthy well-screened individual. Participants will receive either 15mL of the investigational product with 85 mL of normal saline or 100 mL of normal saline only (placebo). The expected duration of participation in the study is a maximum of 61 days, which includes 1-day screening prior to treatment and 60 days following the first treatment.

This study is part of what is called a platform study. This platform study, called the "PRACTICAL" study is designed so that various interventions can be evaluated at the same time against standard therapy. This allows researchers to compare these newer interventions to each other as well as to the established usual practice and helps them explore different ways to potentially improve the management of lung injury. Within the platform study there are various different sub-studies that have their own interventions and procedures. This domain sub-study is the "Mechanical Ventilation Study" and it is a multi-centre, randomized, open-label trial that will evaluate multiple ventilation strategies in comparison to conventional lung-protective ventilation in patients with acute hypoxemic respiratory failure (AHRF). This domain will enroll perpetually, as interventions are added, continued, or discontinued. Researchers for this study are looking for different types of ventilation strategies (ways that the ventilators control settings can be adjusted) that may be the most helpful for people in their recovery, while also reducing lung damage caused by the ventilator.

The protocol aims to improve standard of care, by ensuring an agile research infrastructure, with an ability to rapidly assess interventions during epidemic transmission of one or more respiratory pathogens adversely affecting public health.

Trials within this protocol can be adaptive, will be randomized, and will have superiority as the primary objective. Comparisons in the trials may be between an unlicensed agent to a blinded placebo plus standard of care (SOC), between an approved off-label agent to a blinded placebo plus SOC, among several active interventions (blinded or non-blinded; i.e., a comparative effectiveness study), or among different treatment strategies.

The purpose of this research is to find out if a drug called ganciclovir can prevent cytomegalovirus (CMV) reactivation, in which the virus wakes up from an inactive state, in patients with respiratory failure associated with severe sepsis. In order for you to take part in this study, we verified that you also have previously had an infection with a virus called Cytomegalovirus (CMV). Ganciclovir is an FDA approved drug that has been widely used for the prevention and treatment of CMV in patients with weakened immune systems. A total of 482 patients will be enrolled in this study at sites throughout the US.