A Study of Brexanolone for Acute Respiratory Distress Syndrome (ARDS) Due to Coronavirus Disease 2019 (COVID-19)

Inclusion Criteria: * Participant was confirmed positive for the novel coronavirus responsible for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection as determined by polymerase chain reaction (PCR) at Screening * Participant had a presumptive diagnosis of ARDS at Screening and partial pressure of arterial oxygen (PaO2)/fraction of inspired oxygen (FiO2) (ratio of partial pressure of arterial oxygen to fraction of inspired oxygen \[PF ratio\]) less than (\<) 300 prior to randomization * Participant was intubated and receiving mechanical ventilation prior to randomization * Participants must had initiated mechanical ventilation within 48 hours prior to screening, or had an immediate clinical plan for such intervention at time of screening * Participant was likely to survive, in the opinion of the investigator, for at least 72 hours from the time of screening Exclusion Criteria: * Participant had fulminant hepatic failure at Screening * Participant had end stage renal disease at Screening * Participant had a known allergy to progesterone, allopregnanolone, or any excipients in the brexanolone injection * Participant was concurrently participating in another clinical trial for an investigational product or device at screening