UPDATED: FDA panel rejects Cornerstone Therapeutics' heart drug

Cornerstone Therapeutics ($CRTX) was dealt a severe setback today, losing an FDA panel vote on whether their new drug for treating low sodium in the blood should be approved. The agency's outside experts voted 5 to 3 against an approval for hyponatremia spurred by syndrome of inappropriate antidiuretic hormone secretion, or SIADH. They also unanimously rejected the use of the drug to treat heart-failure patients. The news triggered a quick meltdown in the biotech's share price.

The drug lixivaptan is designed to treat a condition characterized by low sodium levels in the blood which can trigger some severe physical reactions, such as the swelling of the brain and respiratory problems, which can be potentially fatal. Six million Americans suffer from the ailment, which is linked to congestive heart failure and erratic chemical signals spurred by SIADH.

But Reuters reports that the panelists were unconvinced by Cornerstone's data review, casting doubt on whether the drug's risks outweighed the limited benefits the biotech presented. A majority wanted to see additional trial data before they could recommend an approval on SIADH. The heart-failure indication had been opposed by the agency's staff and never had a chance in front of the panel.

Minutes after trading resumed in Cornerstone stock, shares plunged 35% Thursday afternoon. Cornerstone, however, isn't throwing in the towel yet.

"While we respect the views of the CRDAC, we view today as another step in the process of bringing lixivaptan to market for patients with hyponatremia using the established surrogate endpoint of serum sodium correction," said CEO Craig A. Collard. "Cornerstone is committed to continuing to work with the FDA throughout the approval process building upon meeting our primary endpoint in each pivotal Phase III trial."

Two days ahead of an expert panel review, FDA reviewer Nancy Xu issued a report which concluded that lixivaptan "was associated with a significant increase in serum sodium concentrations compared to placebo." And while she thought the outside experts should provide a thumbs up for the drug, an elevated risk of death seen in the drug arm--not firmly linked to the drug itself--spurred Xu to recommend against using it in patients "requiring intervention to raise sodium concentration urgently to prevent or to treat serious neurological symptoms."

The FDA often takes the advice of its advisory committees, and the agency has an action date of Oct. 29 on its approval decision.

- read the release
- here's the story from Reuters