FDA posts Vivitrol briefing documents

FDA said in briefing documents posted ahead of an advisory committee meeting on Thursday that Alkermes Inc. (NASDAQ:ALKS) provided convincing evidence that Vivitrol naltrexone prevents relapse to opioid use in opioid-dependent patients in a single Russian Phase III trial. However, the agency expressed concerns about whether ethnic factors might render the data inapplicable to the U.S. population. The documents noted a lower rate of adverse event reporting in the trial for the sNDA compared to the U.S. studies in Vivitrol's original NDA, which the agency said could be attributed to cultural norms in Russia.

FDA will ask the Psychopharmacologic Drugs Advisory Committee whether differences between the studied population and the U.S. target population create a need for a bridging study to assure that Vivitrol would be effective in the U.S. population. The injectable sustained-release formulation of naltrexone in polylactide co-glycolide polymer microspheres is already marketed in the U.S. to treat alcohol dependence. ...