Cardurion Pharmaceuticals has started dosing of subjects in CARDINAL-HF, a Phase II clinical trial of its phosphodiesterase-9 (PDE9) inhibitor, CRD-740, to treat heart failure.

The company also announced that multiple sites for the trial are opened.

The randomised, placebo-controlled CARDINAL-HF trial is said to be the first Phase II proof-of-concept trial of a PDE9 inhibitor in heart failure.

It has been designed to evaluate CRD-740’s effects in both forms of heart failure and in key subsets of the patients.

CRD-740 targets PDE9 enzyme which metabolises cardiac cGMP that is created by the natriuretic peptide receptor (NPR) pathway.

The NPR pathway activation has proven clinical benefit in both types of heart failure.

The company stated that the inhibition of PDE9 using CRD-740 is a new process that can maximise the activation of NPR pathway.

More than 650 participants at over 100 trial sites across the globe will be enrolled in the CARDINAL-HF trial, which builds on the encouraging data obtained in the company’s Phase Ib trial.

Chronic and stable patients with both reduced and preserved ejection fraction heart failure (HFpEF) will participate in the trial.

Cardurion Pharmaceuticals CEO Peter Lawrence said: “The launch of this large-scale trial is a significant milestone for Cardurion and for millions of patients who suffer from heart failure and are underserved by currently available therapies.

“We are gratified to have assembled a world-class group of cardiovascular experts to help oversee its execution.

“We believe that CARDINAL-HF will rigorously test CRD-740 in both HFrEF and HFpEF, allowing us to assess the value of PDE9 inhibition in these patient populations, including important subgroups of patients who are on other heart failure medications. The data from this trial will be extensive and allow for robust decision-making for Phase III.”

Additionally, CRD-740 is being evaluated on a background of standard of care treatments for providing crucial information regarding the potential benefits of CRD-740 when given along with guideline-directed treatments.