Inspire Pharmaceuticals has revealed that a second Phase III clinical trial to evaluate denufosol tetrasodium as a treatment for cystic fibrosis has failed.

The study did not attain statistical significance on the primary efficacy endpoint, which was defined as change from baseline in forced expiratory volume in one second (FEV1) at week 48.

In the 466-patient, double-blind and placebo-controlled trial, patients treated with denufosol showed an improvement of 40ml, compared to 32ml in patients receiving a placebo.

No statistically significant differences were observed between denufosol and the placebo for the key secondary endpoints.

Inspire president and CEO Adrian Adams said the results were disappointing and unexpected given the treatment effect observed in the first Phase III trial.

“We will conduct a thorough analysis of the data to fully understand the results from this trial and the impact on any future development of denufosol and on the company going forward,” Adams added.