A phase 3 extension study of ataluren (PTC124) in subjects with nonsense-mutation-mediated cystic fibrosis

This Phase 3 trial (NCT01140451) was conducted in 31 sites across 11 countries (Europe, Israel and USA) to evaluate the long-term safety of ataluren (PTC124) in adult and pediatric patients with nonsense-mutation-mediated CF who had completed the preceding 48-week randomized double-blind study. One hundred and fourty-eight subjects (≥ 6 years-old) were enrolled in this extension study. They received ataluren 3 times daily (10 mg/kg morning and midday and 20 mg/kg evening) during at least 48 weeks in the extension study. In the 70 patients who had received placebo on the first study, the mean relative change in %-predicted FEV1 was -4.6% on placebo from week 0 to 48 and +1.1% on ataluren from week 48 to week 96. In the 78 patients who had received ataluren on the first study, the mean relative change in %-predicted FEV1 was -0.7% from week 0 to 48 and -0.7% on ataluren from week 48 to week 96. No increase in frequency of previously reported adverse events was observed. In conclusion, the results show a stabilization of lung function in CF patients bearing a nonsense-mutation and receiving a prolonged ataluren treatment. 

The summary of data provided here is from the presentation of study results at the at the North American Cystic fibrosis Conference in Atlanta (GA, USA) in October 2014.