Sarepta Therapeutics suffered another major setback on Friday as Europe's drug regulator decided not to recommend the approval of Elevidys, following mounting regulatory scrutiny and two recent patient deaths linked to the company's gene therapy.

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 U.S. Food and Drug Administration (FDA) is investigating the death of an eight-year-old boy who received Sarepta Therapeutics (NASDAQ: SRPT) gene therapy, Elevidys, for Duchenne muscular dystrophy (DMD).