PTC124 for the Treatment of Cystic Fibrosis

In some patients with cystic fibrosis (CF), the disease is caused by a nonsense mutation (premature stop codon) in the gene that makes the cystic fibrosis transmembrane regulator (CFTR) protein. PTC124 has been shown to partially restore CFTR production in animals with CF due to a nonsense mutation. In an ongoing Phase 2a study being performed at the Hadassah University Hospital - Mount Scopus in Israel, patients with nonsense-mutation-mediated CF have received PTC124 in two 14-day treatment courses. Preliminary results from that study indicate that PTC124 has pharmacodynamic activity of PTC124 in CF and that PTC124 can be safely administered in this patient population. This Phase 2b extension study is designed to evaluate the activity and safety of 3 months (approximately 84 days) of continuous treatment with PTC124 in the same patients who were enrolled to the Phase 2a study. The main purpose of this study is to understand whether PTC124 can be safely administered and achieve pharmacodynamic activity in patients with CF due to a nonsense mutation.