• Men and women aged 18-75 years of age

• Presence of the following criteria for moderate to severe ARDS as defined by the Berlin Criteria within 24 hours of the first infustion:

‣ Onset within 7 days of known clinical insult or requiring increasing respiratory rate, increasing oxygen flows, or increased work of breathing, and

⁃ Bilateral lung opacities not fully explained by pleural effusions, atelectasis, or nodules, and

⁃ PaO2/FiO2 (P/F ratio) ≤ 200 mm Hg, and

⁃ Invasive or noninvasive ventilation with a minimum PEEP 5 cm H2O or minimum of continuous positive airway pressure (CPAP) 5 cm H2O, or High Flow Nasal Oxygen at ≥ 30 L/min, and

⁃ Respiratory failure not fully explained by cardiac failure or fluid overload.