Acadia Pharmaceuticals shares plunged 22 percent Wednesday after a report the Food and Drug Administration will re-examine its only drug.
Nuplazid, which treats hallucinations and delusions from psychosis associated with Parkinson's disease, has been scrutinized for reports of people dying while taking it. Lawmakers grilled Commissioner Scott Gottlieb in a hearing about why the agency approved the drug and what it would take to have it removed from the market.
Gottlieb told members of Congress he would "take another look" at Nuplazid, CNN reports. The FDA told CNN this week it began conducting a new evaluation of the drug several weeks ago, before Gottlieb was questioned about it.
The drug was first approved in 2016.
An FDA spokeswoman confirmed to CNBC the agency is conducting an evaluation of available information about Nuplazid. An Acadia spokesman referred to the FDA's statement, which noted the review does not mean the FDA has determined the drug has a new risk and the agency does not suggest doctors stop prescribing it and patients stop taking it.
Acadia's stock has plummeted 56 percent over the past year.