Acura Pharmaceuticals Inc said a painkiller made with its abuse-deterrent technology did not show statistically significant results in reducing likability among abusers, sending its shares down as much as 34 percent in extended trading.
The mid-stage study showed that Acura's tablet, being tested for potential abuse by snorting, had a slightly lower measure of liking when compared with the generic hydrocodone/acetaminophen tablet.
The company said it expects a delay in the submission of a marketing approval application for Aversion H&A, its most advanced drug in development.
MLV & Co analyst Graig Suvannavejh said the drug could still get approval but potential partners could offer less because it has not shown to reduce the potential for abuse.
Suvannavejh said the company could include in the label positive data from secondary goals.
The trial showed the subjects disliked taking the drug at some point in the treatment.
Acura said there were no serious adverse events reported in the trial.
The company said it did not expect to conduct additional nasal abuse studies though it is yet to meet with the U.S. Food and Drug Administration to discuss the results.
The drug, which contains hydrocodone bitartrate and acetaminophen, was earlier developed by Pfizer Inc. The combination is also sold under the brand name of Vicodin by AbbVie Inc.
Acura's technology, titled Aversion, consists of inactive ingredients which form a gelatinous mixture when the tablets are dissolved for injecting, or cause a burning sensation when the tablets are snorted.
Acura's pain drug Oxecta, generically known as oxycodone HCl, using the Aversion technology was approved by the FDA in 2011.
Shares of the company were down 20 percent at $1.50 in trading after the bell.
(Editing by Don Sebastian)