Acura down 44 percent after FDA rejects Acurox

Acura Pharmaceuticals Inc. plunged the most in almost eight years after the company failed to win a U.S. panel's backing to sell its experimental painkiller Acurox.

The shares of Acura, based in Palatine, fell $1.95, or 33 percent, to $3.95 at 9:41 a.m. in Nasdaq Stock Market composite trading. The stock earlier dropped 43 percent, the biggest decline since November 2002. King, which is co-developing the medicine, declined 22 cents, or 2 percent, to $10.88 on the New York Stock Exchange.

Data submitted by the companies didn't show the abuse-deterrent properties of Acurox are effective enough to support its approval, outside advisers to the Food and Drug Administration said in a 19-1 vote yesterday in Gaithersburg, Maryland. While the FDA usually follows the recommendations of its advisory panels, the agency isn't required to do so.

King, based in Bristol, Tennessee, partnered with Acura to help develop Acurox, a short-acting tablet for moderate to severe pain that combines the narcotic oxycodone and niacin. Adding niacin, a B vitamin, is intended to cause unpleasant skin flushing in people who swallow too many of the tablets. The medicine also has properties to prevent crushing, melting or snorting for a quick high.

Acurox would be the first immediate-release painkiller formulated to prevent abuse. If approved, the drug may generate $58.3 million in sales for King in 2012, or 3.2 percent of the company's total revenue, according to the average estimate of seven analysts surveyed by Bloomberg.