Ensifentrine as a Novel, Inhaled Treatment for Patients with COPD

James F Donohue,1 Tara Rheault,2 Margot MacDonald-Berko,2 Thomas Bengtsson,3 Kathleen Rickard2 1Division of Pulmonary and Critical Care Medicine, University of North Carolina, School of Medicine, Chapel Hill, NC, USA; 2Verona Pharma plc, Raleigh, NC, USA; 3Stat Mind AB, Lund, SwedenCorrespondence: Tara Rheault, Verona Pharma, 8045 Arco Corporate Drive, Suite 130, Raleigh, NC, 27617, USA, Tel +1 646-530-2126, Email tara.rheault@veronapharma.comAbstract: Ensifentrine is a novel, potent, and selective dual inhibitor of phosphodiesterase (PDE)3 and PDE4 designed for delivery by inhalation that combines effects on airway inflammation, bronchodilation and ciliary function in bronchial epithelia. In Phase 2 studies in subjects with COPD, ensifentrine demonstrated clinically meaningful bronchodilation and improvements in symptoms and health-related quality of life when administered alone or in combination with current standard of care therapies. Ensifentrine is currently in late-stage clinical development for the maintenance treatment of patients with COPD. This review summarizes non-clinical data as well as Phase 1 and Phase 2 efficacy and safety results of nebulized ensifentrine relevant to the maintenance treatment of patients with COPD.Keywords: RPL554, nebulized therapy, chronic obstructive pulmonary disease, clinical efficacy, drug developmen