The drug has been shown to affect a positive change in the CFTR chloride channel activity (also known as chloride conductance), and restore the production and function of the CFTR protein; a protein that is lacking in cystic fibrosis patients.
Available treatments for cystic fibrosis are designed to alleviate the symptoms of the disease, whereas results from these phase II trials suggest that PTC124 may actually operate on the cause of the disease itself.
In the 15 patients included in the interim analysis, statistically significant results were observed in the trials’ primary endpoint of change in CFTR chloride channel activity.
Statistically significant improvements in other endpoints, including lung function and weight were also observed. Several patients also reported improvement in well-being, decrease in cough, decreased mucus thickness, and easier clearing of mucus.
“We believe that these results suggest that PTC124 has meaningful pharmacological activity that is consistent with our hypothesis that treatment with PTC124 can restore the production and function of CFTR protein in patients with cystic fibrosis caused by a nonsense mutation,” said Dr Stuart Peltz, president and CEO of PTC. “We also believe that this is the first time such activity has been observed in a clinical trial of an oral therapy for cystic fibrosis.”