Three patient deaths linked to neuromuscular drugs developed by Sarepta Therapeutics (NASDAQ:SRPT) have drawn regulatory scrutiny on the viral vector used in the company’s gene therapy platform technology.

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

Shipments will halt by close of business Tuesday evening, the company said. Sarepta had initially rejected the agency’s request, which was issued Friday.