PTC Therapeutics Inc said on Thursday it would stop developing its cystic fibrosis drug after it failed to meet the main goal of a late-stage study.
The company's shares plunged 25.3 percent to $9.84 before the bell, after coming off a trading halt.
Cystic fibrosis is a life-threatening condition, where a defective gene disrupts the function of the lungs and digestive system, producing a build-up of thick, sticky mucus leading to inflammation and recurrent bacterial infections.
PTC Therapeutics said the drug, ataluren, failed to induce statistically significant improvements in symptoms, versus a placebo, in patients with nonsense mutation cystic fibrosis, a sub-type of cystic fibrosis.
PTC said it would withdraw its application to market ataluren to treat cystic fibrosis in Europe.
Ataluren is approved in Europe to treat Duchenne muscular dystrophy that is caused by a nonsense mutation in ambulatory patients aged five years and older.
(Reporting by Akankshita Mukhopadhyay in Bengaluru; Editing by Savio D'Souza)