Talk about a stock sell-off. Try a stampede.

Early Monday, Triangle-based Biocryst (Nasdaq: BCRX) disclosed news that a drug candidate targeting a rare genetic condition (hereditary angioedema, or HAE) had failed. The news set off an immediate plunge in its share price, triggered Wall Street downgrades – and a possible lawsuit.

In trading 10 times the normal daily volume, shareholders abandoned Biocryst with some 9.3 million shares being trade.

Shares fell 71 percent to $1.78, a new 52-week low.

How bad was the wipeout? The 52-week high for the stock is $16.83.

The plunge also slashed Biocryst’s market cap to just north of $130 million.

Wall Street analyst firm Piper Jaffray immediately downgraded the stock to “neutral” from “overweight.” Nedham cut Biocryst to “neutral.”

And as is often the case in such large stock sell-offs, a law firm declared a possible suit:

“Levi & Korsinsky, LLP Announces an Investigation Involving Possible Violations of Federal Securities Laws by the Board of BioCryst Pharmaceuticals, Inc.”

2015 had been a good year for Biocryst, which landed a major federal contract for a possible Ebola treatment and a $45 million licensing agreement for a flu treatment it had received FDA approval for in 2014.

But investors forgot the good news when Biocryst disclosed the trial involving a liquid-filled soft gell formulation of its avoralstate failed to produce effective results.

The “well-designed and executed trial that gave us a clear answer; this dosage form of avoralstat is not a viable formulation to move forward,” said Jon Stonehouse, Biocryst’s CEO, in a statement.

“While we are disappointed in the study results, we learned that meaningfully better exposure is needed for avoralstat to succeed. We expect results from a relative bioavailability study testing a novel solid dosage form of avoralstat by mid-year – the primary goals of this study are to achieve much higher exposures and twice daily dosing.”

However, another formulation is still being tested.

“Our other opportunity to achieve higher exposure of an oral kallikrein inhibitor is with BCX7353 – we expect results from the BCX7353 APeX-1 dose ranging study in HAE patients by year end,” he said.

About Hereditary Angioedema

HAE is a rare, severely debilitating and potentially fatal genetic condition that occurs in about 1 in 10,000 to 1 in 50,000 people. HAE symptoms include recurrent episodes of edema in various locations, including the hands, feet, face, genitalia and airway. In addition, patients often have bouts of excruciating abdominal pain, nausea and vomiting that are caused by swelling in the intestinal wall. Airway swelling is particularly dangerous and can lead to death by asphyxiation.

BioCryst also went endured a huge stock plunge in 2012.