PTC's phase 2 trials suggest PTC124 may be effective in treatment of cystic fibrosis

By Lisa Kerner

Erie, Pa., April 4 - PTC Therapeutics, Inc. said interim results from its ongoing phase 2 clinical trials of PTC124 in patients with cystic fibrosis (CF) due to a nonsense mutation suggest that PTC124 may have pharmacological activity that addresses the underlying cause of CF in these patients.

PTC124 is an orally delivered investigational product candidate that PTC is developing for the treatment of genetic disorders due to nonsense mutations, which alter the genetic code resulting in a shortened, non-functional protein.

In PTC's two comparable phase 2 clinical trials of PTC124 in CF, patients receive two sequential two-week courses of treatment, first at a lower and then at a higher PTC124 dose level, according to a company news release.

The primary endpoint of these trials is the change in the CFTR chloride channel activity (chloride conductance) evaluated using a standardized nasal transepithelial potential difference (TEPD) procedure. Cystic fibrosis patients, who lack sufficient CFTR protein, have an abnormal TEPD chloride conductance, PTC said.

Fifteen patients, all with a nonsense mutation and multiple signs and symptoms of CF, have completed two cycles of treatment. At both dose levels, statistically significant results were observed in mean improvement in chloride conductance, percentage of patients with a chloride conductance response, and percentage of patients with a chloride conductance improvement into the normal range.

PTC said improvements in other endpoints, including lung function and weight, were also observed.

"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," president and chief executive officer Stuart W. Peltz said in the release.

"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."

PTC124 was generally well tolerated, with mild adverse events and no safety concerns identified in patients' physical examinations, vital sign measurements, or electrocardiograms, the company said.

According to the Cystic Fibrosis Foundation, CF affects about 30,000 adults and children in the United States, occurring in 1 of every 3,500 live births.

Located in South Plainfield, N.J., PTC is a biopharmaceutical company focused on the discovery, development and commercialization of orally administered, proprietary small-molecule drugs.

© 2015 Prospect News.
All content on this website is protected by copyright law in the U.S. and elsewhere. For the use of the person downloading only.
Redistribution and copying are prohibited by law without written permission in advance from Prospect News.
Redistribution or copying includes e-mailing, printing multiple copies or any other form of reproduction.