What happened

Shares of BioCryst Pharmaceuticals (BCRX 1.28%) were crashing 32.9% lower as of 10:38 a.m. ET on Friday. The steep decline came after the company announced that it has paused enrollment in three clinical studies evaluating experimental drug BCX9930.

So what

BioCryst stated in a press release that patient enrollment in the Redeem-1, Redeem-2, and Renew clinical trials is being paused while it "investigates elevated serum creatinine levels seen in some patients." Creatinine levels that are too high can indicate severe kidney damage.

We don't know at this point how serious the potential issues are. However, BioCryst said that patients already enrolled in the clinical trials will continue to receive BCX9930 for now.

A person wearing a face mask and a plastic glove pressing a pause button.

Image source: Getty Images.

Redeem-1 and Redeem-2 are phase 2 clinical studies evaluating BCX9930 in treating rare blood disease paroxysmal nocturnal hemoglobinuria (PNH). Renew is also a phase 2 study, evaluating the experimental drug in treating rare kidney diseases complement 3 glomerulopathy, immunoglobulin A nephropathy, and membranous nephropathy.

Now what

While today's sell-off of the biotech stock is understandable, it could prove to be an overreaction. It's possible that BioCryst will resume patient enrollment after completing its investigation. On the other hand, the situation could get worse if the three studies must be placed on clinical hold due to the elevated serum creatinine levels.

BioCryst isn't solely dependent on BCX9930, though. The company's hereditary angioedema drug Orladeyo is already on the market in the U.S. and in several other countries. BioCryst expects the drug to generate sales of at least $250 million this year and reach peak annual sales of around $1 billion.