Alkermes, Inc. (NASDAQ: ALKS) today announced that results from the phase 3 clinical study of VIVITROL® (naltrexone for extended-release injectable suspension) in opioid dependence have been published by The Lancet. The six-month, phase 3 trial met its primary endpoint and showed significantly greater opioid-free weeks among patients treated with VIVITROL, compared to placebo. VIVITROL is the first and only non-addictive, non-narcotic, once-monthly medication approved by the U.S. Food and Drug Administration (FDA) for the prevention of relapse to opioid dependence, following opioid detoxification. VIVITROL should be used along with psychosocial support such as counseling. In contrast to conventional agonist therapies that maintain stimulation of opioid receptors, VIVITROL is an opioid-blocking antagonist that, when administered once per month, occupies the opioid receptor, thereby helping to prevent patients from relapsing to opioid dependence.

“There has been a dramatic increase in the prevalence of opioid dependence, which is a serious, life-threatening disease characterized by high rates of relapse, yet there are so few medications available to treat opioid dependence,” stated Evgeny Krupitsky, M.D., Ph.D., Professor of Psychiatry, St. Petersburg State Pavlov Medical University and Head of the Department of Addictions at the Bekhterev Research Psychoneurological Institute. “The robust data from this phase 3 clinical trial showed that treatment with VIVITROL helped opioid-dependent patients remain drug-free with just one injection per month. VIVITROL is the only once-monthly medication that offers patients and physicians a non-narcotic treatment option to help fight this challenging disease.”

The pivotal study also met all secondary endpoints, including opioid craving, self-reported opioid use, study retention rate and incidence of physical opioid dependence. Patients in both the VIVITROL and placebo groups received counseling.

“To date, there has been strong recognition from addiction experts and the treatment community that VIVITROL is an important new treatment option for opioid dependence, and the publication of the phase 3 data is an opportunity for us to more broadly share the comprehensive clinical results demonstrating VIVITROL’s safety and efficacy with the addiction treatment community,” said Richard Pops, Chief Executive Officer of Alkermes. “Alkermes is committed to advancing the field of addiction treatment through the development of new medications that help patients better manage their disease.”

In the phase 3 study, patients treated once-monthly with VIVITROL demonstrated statistically significant higher rates of opioid-free urine tests during the evaluation phase, compared to patients treated with placebo, as measured by the cumulative distribution of clean urine tests (p<0.0002). Data showed that the median patient taking VIVITROL had 90% opioid-free urine tests. A greater percentage of patients in the VIVITROL group remained in the study compared to the placebo group. Safety was assessed through monitoring of treatment-emergent adverse events, vital signs, biochemistry and hematology urine/blood tests including liver function tests, physical examination of injection-sites, and baseline and endpoint electrocardiograms. VIVITROL was generally well tolerated in the study; two patients in each treatment arm discontinued due to adverse events. The most common clinical adverse events experienced by patients receiving VIVITROL during the study were hepatic enzyme elevations, nasopharyngitis and insomnia.

VIVITROL Phase 3 Study Design

The phase 3 randomized, multi-center study was designed to assess the efficacy and safety of VIVITROL compared to placebo treatment in opioid-dependent subjects who had been recently detoxified and abstinent from opioids for a minimum of seven days prior to treatment initiation. Two hundred and fifty subjects were randomized to receive once-monthly injections of either VIVITROL 380 mg or placebo in combination with counseling for six months. The primary efficacy endpoint was the response profile based on the rate of urine drug tests that were free of opioids during the last 20 weeks of the 24-week double-blind treatment period, as measured by the cumulative distribution of clean urine tests. 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. All participants who completed the randomized portion of the study were eligible to continue in an open-label extension phase and receive VIVITROL once-monthly in combination with counseling for an additional thirteen months.

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About Opioid Dependence

In addition to the use of heroin, opioid dependence includes the non-medical use of FDA-approved opioid analgesics, including prescription pain relievers, and represents a growing public health problem in the U.S. According to the 2009 U.S. National Survey on Drug Use and Health, an estimated 1.6 million people aged 18 or older were dependent on pain relievers or heroin.¹ The overall cost of heroin addiction in the U.S. has been estimated to be approximately $22 billion, including productivity losses, criminal activity, healthcare and social welfare costs.²