Acura Pharmaceuticals Announces Top-Line Results of a Clinical Study Assessing Abuse Liability

PALATINE, IL--(Marketwired - Aug 26, 2013) - Acura Pharmaceuticals, Inc. (NASDAQ: ACUR) today announced top-line results from Study AP-ADF-301 (Study 301), a phase II clinical study in 40 recreational drug abusers assessing the abuse liability of snorting a crushed hydrocodone bitartrate with acetaminophen tablet formulated with Acura's abuse deterrent AVERSION technology (AVERSION H&A).

The results for AVERSION H&A in Study 301 were consistent in certain respects with the results of a similar study for another AVERSION product containing oxycodone hydrochloride, which has been approved by the US Food and Drug Administration (FDA). Study 301's primary endpoint indicated AVERSION H&A had slightly lower numeric mean maximum drug liking (Emax:72.1) compared to an equivalent dose of a generic hydrocodone/acetaminophen tablet (Generic H&A: Emax: 75.6) currently on the market, however these results were not statistically significant (p > 0.025).

The secondary endpoints demonstrated the effects of the AVERSION ingredients on drug snorting. AVERSION H&A's mean minimum liking (Emin:40.2) was less than Generic H&A (Emin:50.4) (the difference being statistically significant at p=0.0003). The mean minimum drug liking for AVERSION H&A and the placebo control were 40.2 and 48.8, respectively (the difference being statistically significant at p=0.0042). A score below 50 indicates a subject disliked the drug they were taking at some point during the treatment (a score of 50 means neither like or dislike), and a score greater than 50 indicates they liked the drug they were taking.

The mean minimum liking results correlated closely the Overall Drug Liking score (ODL) and Take Drug Again assessment (TDA). ODL assessed the subject like or dislike for the drug experience 12 hours after taking the dose. The ODL for AVERSION H&A (52.7) was lower than Generic H&A (71.0) (the difference being statistically significant at p=0.0001) with a score of 50 indicating a neither a like or dislike. TDA assessed a subject's willingness to take the drug again assessed 12 hours after taking the dose. The TDA for AVERSION H&A (45.1) was lower than Generic H&A (71.0) (the difference being statistically significant at p=0.0001) with the AVERSION H&A score below 50 indicating an unwillingness to take the drug again.

There were no serious adverse events reported for AVERSION H&A. There was no sequence effect identified in the study but a carryover effect between the 5 study crossover periods was identified for the Emax measure but not the Emin measure. This effect is being further evaluated.