On Mar. 22, 2022, Windtree Therapeutics announced results from its Phase 2 study of lucinactant (KL4 surfactant) for patients with severe COVID-19 associated acute respiratory distress syndrome (ARDS) and lung injury.

The rationale for the study was that the SARS-CoV-2 virus causing COVID-19 uses the angiotensin-converting enzyme 2 (ACE2) receptor for entry into host cells. The ACE2 receptor is found on alveolar Type 2 cells in the lung. Type 2 cells are the source of pulmonary surfactant production. When these cells are infected and damaged, surfactant production is impaired, increasing the risk for respiratory failure as surfactant is necessary for the lungs to stay inflated and for proper gas exchange. Surfactant deficiency is known to contribute to the pathophysiology of ARDS, respiratory failure, and lung injury in patients on mechanical ventilation.

The Phase 2 trial was designed to assess feasibility, safety, and tolerability of administration of reconstituted lyophilized lucinactant in these critically ill patients. The multicenter, single-arm study enrolled 20 critically ill patients who were intubated and on mechanical ventilation due to severe COVID-19 associated ARDS. Patients received lucinactant as a liquid via the endotracheal tube assessing safety and tolerability of the administration procedure and of the drug. Oxygenation and other physiological responses were also measured. Study sites were in the U.S. and Argentina.