Verona Pharma plc, a biotechnology company focused on developing novel treatments for chronic respiratory diseases, announces the results of an exploratory, placebo-controlled, double-blind clinical trial designed to specifically evaluate the anti-inflammatory properties of RPL554 in healthy subjects challenged with an inhaled irritant. This dual PDE3/4 inhibitor is under development as a novel, first-in-class, inhaled treatment for COPD (chronic obstructive pulmonary disease) and asthma.

This exploratory study showed a statistically significant reduction of total cells as well as in various types of inflammatory cells entering the airways in RPL554 treated, compared to placebo treated, subjects. The primary end point chosen for this exploratory trial was a reduction in the proportion of neutrophil cells, an inflammatory cell type recognised for its central role in COPD and severe asthma, to total inflammatory cells in the sputum and secondary endpoints included reductions in total inflammatory cell numbers. While there was a strong trend in favour of the primary endpoint, the study narrowly missed reaching statistical significance even though there was a highly significant reduction in the absolute number of neutrophils. Importantly, there were also statistically highly significant reductions in various types of inflammatory cells entering the airways in RPL554 treated subjects, providing positive evidence of the drug's anti-inflammatory effects.

The study also showed that the drug was well tolerated with adverse events being mild and not significantly different to placebo. Consistent with earlier clinical studies with RPL554, there was no evidence of cardiovascular or gastrointestinal side effects.

Verona Pharma is currently developing RPL554, in a nebulised form, as a novel bronchodilator to treat patients with severe COPD, a significant unmet medical need. Previous clinical trials conducted by the company have demonstrated that RPL554 is a potent bronchodilator with fast onset of action in both COPD and asthma patients. Near- to mid-term clinical development will focus on its bronchodilator properties in more severe patients. The Board believes that this focussed development will accelerate shareholder value growth. It is intended that the drug's anti-inflammatory activity will be explored more fully in later studies to examine further the drug's potential as a dual bronchodilator and anti-inflammatory treatment for patients with respiratory disease.

Professor Dave Singh of the Medicines Evaluation Unit, University of Manchester, who was the Principal Investigator, commented, "RPL554 reduced the number of inflammatory cells in the airways of healthy volunteers, suggesting that the drug may have important anti-inflammatory effects in patients with COPD or asthma. Encouragingly, daily treatment with RPL554 for a week was very well tolerated and continued to show significant bronchodilator activity".

Jan-Anders Karlsson, CEO of Verona Pharma, commented, "We are very excited by the outcome of this trial. The demonstration of significant anti-inflammatory activity with RPL554, coupled with its pronounced bronchodilator effects, makes this a unique drug with significant promise as a new treatment for patients with COPD or asthma. Our near-term focus for the further development of RPL554 is on exploring the drug's significant bronchodilator properties in treating airway obstruction in patients with severe COPD, a disease with a significant unmet medical need. This promises to be the fastest way to bring RPL554 to market."