UK-based Verona Pharma has started the multiple dose part of a Phase II clinical trial of a pressurised metered-dose inhaler (pMDI) formulation of ensifentrine to treat moderate to severe chronic obstructive pulmonary disease (COPD).

Ensifentrine is an investigational, inhaled, dual inhibitor of the phosphodiesterase 3 and 4 (PDE3 and PDE4) enzymes. This mechanism is said to exhibit bronchodilator and anti-inflammatory effects.

The company reported positive efficacy and safety results from the first single-dose part (Part A) of the Phase II trial in 40 moderate to severe COPD patients in March.

According to the data, the drug showed a statistically significant and clinically meaningful increase in lung function, determined by forced expiratory volume in one second (FEV1) versus placebo.

Verona decided to postpone the multiple dose part (Part B) due to safety concerns during the Covid-19 pandemic.

Based on analysis of local infection rates, control measures, and procedures implemented by the UK sites, the company commenced the Part B.

The second part will involve around 30 moderate to severe COPD patients who participated in Part A. It will be carried out at two sites in the UK.

Participants will be given a 300µg, 1,000µg or 3,000µg dose of pMDI ensifentrine or placebo twice-daily over one week for four treatment periods.

The primary endpoint of Part B is the improvement in lung function after seven days of treatment, while secondary endpoints include safety and tolerability, among others.

Verona Pharma president and CEO David Zaccardelli said: “Data from the single dose part of this pMDI study are very encouraging and consistent with data from Phase II clinical trials with our nebulised and dry powder inhaler (DPI) formulations of ensifentrine.

“We look forward to providing further updates on this pMDI study and our upcoming Phase III ENHANCE trials and pilot trial in hospitalised patients with Covid-19.”

Data from the second part of the study is expected to be reported in the first half of 2021.

In October last year, Verona Pharma closed patient enrolment in a Phase IIb trial of nebulised ensifentrine to treat moderate-to-severe COPD.