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Statistically Significant Reduction Results Reported in Alcohol Dependent Patients in Phase III Trial of Vivitrex
“These data show that the long-acting formulation of Vivitrex results in meaningful clinical benefit for male alcohol-dependent patients and can significantly advance the practice of treating alcoholism,” said James Garbutt, M.D., Professor of Psychiatry at University of North Carolina at Chapel Hill and a lead investigator for the Vivitrex Phase III trial. “As one of the largest studies ever conducted for alcohol pharmacotherapy, this landmark Phase III trial shows that treatment with Vivitrex resulted in a reduction in heavy drinking events and highlights the role that drug therapy can play in helping patients break the cycle of alcoholism.”
“Based on the results of this successful study, Alkermes intends to move forward with our extensive development plans for Vivitrex,” said Richard Pops, Chief Executive Officer of Alkermes. “These Phase III results represent an important milestone in reaching our ultimate goal of developing Vivitrex into an innovative product that offers the potential to improve outcomes for alcohol-dependent patients. We look forward to sharing these data with the U.S. Food and Drug Administration as we proceed on our path towards submission of a New Drug Application.”
Alkermes will complete the full analysis of the trial data, including impact of gender. The company plans to submit the data for publication in a peer-reviewed journal.
“The data from this Phase III trial with Vivitrex indicates a potentially significant development in treating people with alcohol problems,” said Richard Rosenthal, M.D., immediate past president of the American Academy of Addiction Psychiatry (AAAP). Kathleen Brady, M.D., Ph.D., president of AAAP adds “A new contribution to our tools to treat the major public health problem of alcohol abuse and dependence is welcome.”
Vivitrex is a proprietary long-acting formulation of naltrexone based on Alkermes’ Medisorb® injectable, extended-release technology. By providing an extended-release dose administered once monthly, rather than daily, Vivitrex is designed to facilitate compliance with treatment regimens and improve outcomes for alcohol-dependent patients.
Phase III Trial Design
The Phase III clinical trial, a randomized, placebo-controlled, double-blind study, was designed to evaluate the safety and efficacy of Vivitrex in alcohol-dependent patients during a six-month period. The primary endpoint was the event rate of heavy drinking over the six-month period. A heavy drinking event is defined as five or more drinks per day for a man and four or more drinks per day for a woman. The multi-center study enrolled 624 patients, and randomized patients to receive, in addition to psychosocial therapy, Vivitrex 190 mg, Vivitrex 380 mg, or placebo. Vivitrex was administered by injection in a clinical setting once per month for six months. At designated intervals during the study, patients returned to the clinic for study evaluations and psychosocial therapy. Following the six-month treatment period, patients were eligible to enter an extension study designed to collect long-term safety data for an additional 12 months.
Vivitrex was generally well tolerated by patients in the Phase III trial. In patients receiving Vivitrex, the three most common adverse events reported during the six-month study were nausea, headache, and fatigue. Injection site reactions were more commonly seen in the treatment groups versus the placebo group. Less than 2% of the patients discontinued in the trial due to injection site reaction.
Challenges of Treating Alcohol Dependency
The treatment approach for alcohol dependence includes detoxification, psychosocial therapy, and, more recently, pharmacotherapy. As a pharmacotherapy, naltrexone has been shown to reduce relapse to heavy drinking in alcohol-dependent patients, decrease the number of drinks consumed when relapse does occur, and promote abstinence.2 Naltrexone is a potent opioid receptor antagonist and has been reported to reduce both the craving and the reinforcing euphoric qualities of alcohol.3
Although naltrexone in oral form has been shown to be effective as a maintenance agent in the treatment of alcohol dependence, a major limitation of its utility can be poor adherence to therapy. In the treatment of alcohol dependence, oral naltrexone is indicated for daily administration. In a clinical study led by researchers at the University of Pennsylvania Medical Center comparing oral naltrexone to placebo, it was reported that greater than 40% of patients treated with naltrexone were noncompliant with the daily oral regimen.4 That study also reported that, for medication-noncompliant patients, relapse to clinically significant drinking was similar to placebo treated patients and significantly higher than the rate observed with medication-compliant patients.
Prevalence of Alcohol Dependency
In the U.S., it is estimated that 18 million people (age 18 years and older) suffer from alcohol dependency or meet diagnostic criteria for alcohol abuse disorder.5 There are 2.3 million alcohol-dependent persons who seek treatment for their condition each year.6 More than half of all adult Americans have direct family experience with alcohol problems. Alcohol abuse is the cause of more than 100,000 deaths in America each year.7 According to a study by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) and the National Institute on Drug Abuse (NIDA), in 1998, alcohol dependence and abuse cost Americans – private citizens, corporations, local and state governments and the federal government – a total of $184.6 billion.8
Vivitrex is a long-acting, injectable form of naltrexone that was developed utilizing Alkermes’ proprietary Medisorb drug-delivery technology. Using the Medisorb technology, naltrexone is encapsulated in microspheres made of a biodegradable polymer that dissolves slowly and releases drug at a controlled rate following intramuscular injection. Upon receipt of regulatory approval, Alkermes plans to commercialize Vivitrex using a specialty sales force to call on addiction specialists and substance abuse centers. Alkermes is in discussions with potential partners about broader commercialization of the product in the U.S. and Europe, and for other indications such as opiate dependence. The Vivitrex clinical development program has been funded in part with a Small Business Innovation Research Program grant from the National Institute on Alcohol Abuse and Alcoholism (NIAAA).