Europe's medicines regulator did not recommend the approval of Sarepta Therapeutics' gene therapy Elevidys for a type of rare muscular dystrophy, the health agency said on Friday. Shares of the company were down nearly 17% at $10.

The European Medicines Agency’s drug advisory committee (CHMP) rejected Elevidys for children aged 3 to 7 years who are able to walk, the agency announced Friday. The therapy, which is marketed outside the U.S. by Roche Holding AG (SIX: ROG ), was seeking approval for treating the rare genetic disease that causes progressive muscle weakness.

The European Medicines Agency determined testing failed to prove Elevidys’ benefit and issued a negative opinion that could further jeopardize Sarepta’s financial future.