Biotechnology company Alkermes, Inc. (ALKS) Monday announced positive preliminary results from a phase 3 clinical trial of naltrexone for extended-release injectable suspension, or XR-NTX, for the treatment of opioid dependence. The study met its primary efficacy endpoint, with patients treated in the trial showing statistically significant higher rates of opioid-free urine screens compared with those treated with placebo. Based on this, the company intends to file for FDA approval in the first half of calendar 2010.
Naltrexone, marketed in US as Vivitrol, is currently approved in US as a once-monthly intramuscular injection for the treatment of alcohol dependence. Naltrexone is also marketed in its generic form as naltrexone hydrochloride and marketed under the trade names Revia and Depade.
Alkermes also observed that if approved by FDA for opioid dependence, XR-NTX would be the first and only non-narcotic, non-addictive drug agent available in a once-monthly formulation.
The six-month phase 3 study showed that patients treated once-monthly with XR-NTX demonstrated statistically significant higher rates of opioid-free urine screens, compared to patients treated with placebo, as measured by the cumulative distribution of clean urine screens.
The trial was designed to assess the efficacy and safety of XR-NTX compared to placebo treatment in opioid dependent subjects who have been recently detoxified and abstinent from opioids for a minimum of seven days prior to treatment initiation.
Besides meeting the primary efficacy endpoint, the study also met all its secondary efficacy endpoints, with the most common adverse event during the study being nasopharyngitis and insomnia.
The primary efficacy endpoint was the response profile based on the rate of urine drug screens that were free of opioids, while the secondary efficacy endpoints in the phase 3 study were the study retention rate, craving scores, self-reported opioid use and the incidence of physiologic opioid dependence.
Dr. Herbert Kleber, Professor of Psychiatry, Director, Division on Substance Abuse, Columbia University said, "These robust data show that XR-NTX helped opioid dependent patients become drug-free with just one injection each month."
Richard Pops, Chief Executive Officer of Alkermes, "We look forward to expanding our label beyond alcohol dependence to make XR-NTX available as the first and only non-narcotic, non-addictive, once-monthly treatment option for the millions of patients struggling with opioid dependence."
Alkermes also said that naltrexone may cause hepatocellular injury when given in excessive doses, while indicating that the drug is contraindicated in acute hepatitis or liver failure, and its use in patients with active liver disease must be carefully considered in light of its hepatotoxic effects.
ALKS closed Friday's regular trading at $7.91, down $0.02. on a volume of 0.65 million shares.
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