Shares of Sarepta Therapeutics Inc. (NASDAQ:SRPT) plunged 44 percent in heavy trading Thursday after the FDA posted revised briefing documents for Monday's re-scheduled meeting of the Peripheral and Central Nervous System Drugs (PCNS) Advisory Committee (adcom) to discuss the new drug application (NDA) for its Duchenne muscular dystrophy (DMD) candidate, eteplirsen.