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GlaxoSmithKline drug fails in late-stage trial

The Associated Press

British drug maker GlaxoSmithKline PLC and Dutch biotech Prosensa Holding N.V. said Friday a potential treatment for Duchenne muscular dystrophy failed in a late-stage study to produce a significant difference in patients taking the drug compared with those who had a fake version.

The companies said the potential treatment, drisapersen, did not meet the study's main goal of generating a statistically significant improvement in a six-minute walking distance test compared to the placebo. Researchers also saw no difference in some secondary assessments of motor function like a walk/run test and a stair climb.

The study involved a total of 186 boys, and the company expects to evaluate the results some more before determining a next step for the potential treatment.

Duchenne muscular dystrophy is a rare and fatal genetic disease that causes increasing muscle weakness and affects one of every 3,500 boys born worldwide.

Drisapersen is not approved for use anywhere in the world. Glaxo obtained the worldwide license to develop and sell drisapersen from developer Prosensa in 2009.

U.S.-traded shares of Glaxo climbed 29 cents to $50.56 in afternoon Friday. Prosensa shares plunged $17, or 71 percent, to $7 in very heavy trading.

Shares of competitor Sarepta Therapeutics Inc., which is developing the drug Eteplirsen as a rival treatment, jumped more than 17 percent to $43 by late afternoon.

Citi analyst Yaron Werber said in a research note that the data cast a shadow on the future prospects of drisapersen, potentially removing a competitor and giving Sarepta "a booster shot in the arm".