Verona Pharma plc is a United Kingdom-based bio-pharmaceutical company. The Company is engaged in developing drugs for the treatment of chronic respiratory diseases, such as chronic obstructive pulmonary disease (COPD), asthma and cystic fibrosis. Its program is RPL554, an inhaled, dual phosphodiesterase 3 (PDE3) and phosphodiesterase 4 (PDE4) inhibitors, as a nebulized treatment for patients in hospital with acute exacerbation of chronic obstructive pulmonary disease (COPD) and cystic fibrosis. RPL554 has completed two double-blind placebo controlled randomized Phase II b studies of RPL554: one in mild to moderate asthma and another in mild to moderate COPD. Its other products include VRP700 and NAIPs. VRP700 is an anti-tussive (cough) drug and has completed a Phase II trial. The Company's subsidiaries include Rhinopharma Limited and Verona Pharma Inc.