Verona Pharma plc announces that the World Health Organization approved “ensifentrine” as the recommended International Non-proprietary Name (“INN”) for the company’s drug candidate, RPL554. Ensifentrine is a first-in-class, inhaled, dual inhibitor of the enzymes phosphodiesterase 3 and 4 designed to have bronchodilator as well as anti-inflammatory properties, and is currently in development for the maintenance treatment of chronic obstructive pulmonary disease (“COPD”), cystic fibrosis (“CF”) and potentially asthma. The “-fentrine” stem indicates recognition from the WHO that RPL554 inhibits multiple phosphodiesterases, rather than a single phosphodiesterase, such as phosphodiesterase 3 or 4 alone. In Phase 2 clinical trials completed to date, ensifentrine has been observed to result in bronchodilator effects when used alone or as an add-on treatment to other COPD bronchodilators, and has also shown anti-inflammatory effects in a standard challenge study with COPD-like inflammation in human subjects. Verona Pharma is currently conducting two further Phase 2 clinical trials: one to evaluate a nebulized formulation of ensifentrine as an add-on treatment to dual LAMA/LABA therapy and triple LAMA/LABA/ICS therapy, and the other to evaluate a dry powder inhaler (“DPI”) formulation of ensifentrine for the maintenance treatment of COPD. The company also plans to evaluate ensifentrine in a metered-dose inhaler (“MDI”) formulation as part of a comprehensive clinical program intended to fully demonstrate the clinical utility of ensifentrine in improving the standard of care for COPD. These data will be used to support the planning of the ensifentrine Phase 3 COPD program.