Biotech stock Rapt Therapeutics plummeted to a record low Tuesday after the Food and Drug Administration put two of its clinical studies on hold.
The company is testing a drug called zelnecirnon as a treatment for eczema and asthma. But in a midstage test, one eczema patient experienced liver failure. The cause is unknown, but it could be related to zelnecirnon, Rapt said in a news release.
Patients have stopped receiving the drug, and Rapt isn't enrolling any new patients.
Rapt stock crashed 73.6% to 6.87 on today's stock market. That put the biotech stock at its lowest-ever point.
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Rapt says it has enrolled roughly 350 patients into three studies of zelnecirnon. So far, there has been no evidence of liver toxicity in any other patient. Further, there were no liver issues in early nonclinical testing, Rapt said.
The company says the patient has a complicated medical history, including being allergic to Dupixent, a drug from Regeneron Pharmaceuticals and Sanofi that, among other things, treats asthma and eczema.
The patient has also used an herbal supplement with known ties to liver failure, Rapt said.
Rapt is a highly rated biotech stock with a strong Relative Strength Rating of 93. This means shares rank in the top 7% of all stocks when it comes to 12-month performance, according to IBD Digital.
But, on Tuesday, shares undercut their key moving averages, MarketSmith.com shows.
Follow Allison Gatlin on X, the platform formerly known as Twitter, at @IBD_AGatlin.
