Sarepta Therapeutics failed to win the European drug regulator's backing for its muscle disorder gene therapy on Friday, as the company faces intense regulatory scrutiny after two recent patient deaths tied to the treatment.

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

The Food and Drug Administration won’t sign off on Sarepta Therapeutics Inc. bringing its controversial gene therapy back to the market until the company can persuade US regulators that it won’t cause more deaths,