Long-Term Outcomes of Ataluren in Duchenne Muscular Dystrophy

This study is a long-term study of ataluren in participants with nonsense mutation Duchenne muscular dystrophy.

This study is a randomized, double-blind, placebo-controlled, 72-week study followed by a 72-week open-label period. The purpose is to characterize the long-term effects of ataluren-mediated dystrophin restoration on disease progression. Participants will be randomized in a 1:1 ratio to ataluren or placebo. Participants will receive blinded study drug three times daily (TID) at morning, midday, and evening for 72 weeks, after which all participants will receive open-label ataluren for an additional 72 weeks (144 weeks in total). Study assessments will be performed at clinic visits every 12 weeks during the double-blind period and every 24 weeks during the open-label period. The total sample size of ~250 subjects will include ~160 subjects who meet the criteria for inclusion in the primary analysis population (age 7 to 16 years old, baseline six minute walk distance (6MWD) greater than or equal to (>=) 300 meters, supine to stand >= 5 seconds). The study will be conducted in the United States and other countries around the world.