Key Takeaways Sarepta Therapeutics shares were down nearly 25% early Friday morning.The tumble followed a report that a third patient has died during a clinical trial for its Elevidys drug that treats muscular dystrophy.

The restructuring enacted by Sarepta Therapeutics is expected to save up to $400 million in annual costs. Read why I'm downgrading SRPT stock from Hold to Sell.

These were the most active stocks ahead of Friday's market open: Sarepta Therapeutics Inc.'s stock tumbled 27% after the company said another patient died following gene-therapy treatment, Bloomberg reported,

Sarepta agrees to FDA's black box warning and announces major restructuring, including job cuts and cost-saving measures to meet 2027 goals.

CNBC's Angelica Peebles joins 'Squawk on the Street' with the latest news on Sarepta following a patient death.