On Tuesday, shares of Sarepta Therapeutics (SRPT) plunged after SRPT posted a wider quarterly loss and its key muscular dystrophy treatment received a thumbs down from federal regulators.

A report from the U.S. Food and Drug Administration (FDA), which called the Sarepta Therapeutics application for the drug eteplirsen “premature,” sent SRPT stock plummeting 65% in trading.

SRPT stock hit a 13-month low in the wake of the announcement, Investors Business Daily noted.

SRPT stock was also hammered by Sarepta Therapeutics’ third-quarter results — also released yesterday. SRPT posted a loss 53 cents per share loss, compared to a loss of just 27 cents per share reported during the same time last year.

Sarepta Therapeutics also said its revenue dropped to $4.2 million during the quarter, down 45% from last year. SRPT CEO noted that the Sarepta Therapeutics’ cash position was “strong” and that SRPT intended to continue clinical research on its Duchenne muscular dystrophy treatment.

SRPT stock closed on Tuesday at $13.16 a share.

SRPT has been testing eteplirsen, which is designed to treat Duchenne muscular dystrophy, a rare form of muscular dystrophy that affects one in 3,500 boys around the world. Sarepta Theraputics has been monitoring the progress of 12 young male patients taking the drug.

Despite the FDA’s assessment, SRPT officials said that the Sarepta Therapeutics remained committed to eteplirsen and would continue research on the drug.

SRPT stock rose slightly in Wednesday pre-market trading.