What happened

Shares of Ardelyx (NASDAQ:ARDX) were jumping 10.3% as of 3:19 p.m. EST on Tuesday. The nice gain came after the biopharmaceutical company announced positive results from a phase 3 clinical study evaluating tenapanor as monotherapy for treating hyperphosphatemia in patients with chronic kidney disease (CKD) on dialysis.

So what

Ardelyx's late-stage study included 419 patients who received tenapanor and 137 patients who received sevelamer, a drug currently used as a standard treatment for hyperphosphatemia in CKD patients. The study achieved its primary endpoint of a statistically significant difference in least square mean serum phosphorus change compared with placebo.

Hand wearing glove and holding a test tube

Image source: Getty Images.

The company reported that tenapanor was "generally well tolerated," although more than half of patients self-reported loose stool or diarrhea, the most common adverse event. Around 90% of these cases were determined to be mild to moderate in severity.

CEO Mike Raab was enthusiastic about the results, stating that they were "very exciting and represent a capstone to our tenapanor clinical development program." Myles Wolf, chief of nephrology at Duke University School of Medicine, said, "If approved, tenapanor is poised to change the way we manage hyperphosphatemia in patients on dialysis." He added that the drug could potentially be "an ideal first-line therapy for patients receiving dialysis for whom new effective treatments are desperately needed."

Now what

While positive clinical results can provide nice catalysts for biotech stocks like Ardelyx, the most important hurdle to jump is regulatory approval. That's the next item on the agenda for Ardelyx. Raab said that the company will now focus on completing and submitting the U.S. regulatory filing for tenapanor by the middle of next year.