Daniel E. Falk

Medications development to treat alcohol dependence: a vision for the next decade

More than 76 million people world‐wide are estimated to have diagnosable alcohol use disorders (AUDs) (alcohol abuse or dependence), making these disorders a major global health problem. Pharmacotherapy offers promising means for treating AUDs, and significant progress has been made in the past 20 years. The US Food and Drug Administration approved three of the four medications for alcoholism in the last two decades. Unfortunately, these medications do not work for everyone, prompting the need for a personalized approach to optimize clinical benefit or more efficacious medications that can treat a wider range of patients, or both. To promote global health, the potential reorganization of the National Institutes of Health (NIH) must continue to support the National Institute on Alcohol Abuse and Alcoholisms (NIAAAs) vision of ensuring the development and delivery of new and more efficacious medications to treat AUDs in the coming decade. To achieve this objective, the NIAAA Medications Development Team has identified three fundamental long‐range goals: (1) to make the drug development process more efficient; (2) to identify more efficacious medications, personalize treatment approaches, or both; and (3) to facilitate the implementation and adaptation of medications in real‐world treatment settings. These goals will be carried out through seven key objectives. This paper describes those objectives in terms of rationale and strategy. Successful implementation of these objectives will result in the development of more efficacious and safe medications, provide a greater selection of therapy options and ultimately lessen the impact of this devastating disorder.

Percentage of Subjects With No Heavy Drinking Days: Evaluation as an Efficacy Endpoint for Alcohol Clinical Trials

BACKGROUND Percent subjects with no heavy drinking days (PSNHDDs), an efficacy end point recommended by the Food and Drug Administration, considers abstinent individuals or those engaging in low-risk drinking behavior as successful responders to treatment. As PSNHDD has been used infrequently in previous alcohol clinical trials, we evaluated the utility and validity of the PSNHDD outcome measure in 2 large alcohol clinical trials. METHODS Data sets from 2 alcohol trials, COMBINE and a multisite topiramate trial, were used to analyze PSNHDDs and other traditional end points for the topiramate, naltrexone, acamprosate, and placebo groups. Effect sizes of PSNHDDs were determined for each month of active treatment and by varying grace periods-early periods in the trial where outcome is not considered in the analysis-and were compared with that of other traditional outcome measures. Long-term outcomes were compared for groups that had no heavy drinking days versus those that had heavy drinking days during active treatment. RESULTS PSNHDD effect sizes were significant for both topiramate (0.34 and 0.25 at months 2 and 3, respectively) and naltrexone (0.24 and 0.26 at months 3 and 4, respectively). Given a 2-month grace period for naltrexone, the effect size of PSNHDDs was comparable to the effect sizes using traditional outcome measures. With a 1-month grace period for topiramate, it was greater than the majority of traditional outcome measures. Little is gained by allowing up to 1, 2, or 3 heavy drinking days as an end point. Subjects with no HDDs during treatment fared better than those with some HDDs on drinking outcomes and alcohol-related consequences during a 1-year follow-up. CONCLUSIONS PSNHDD appears to be a clinically informative end point measure, especially when used with a grace period, and is as sensitive as most traditional outcome measures in detecting differences between the medication and placebo groups. Nonetheless, these findings should be replicated in other clinical data sets, particularly with medications that work via different mechanisms.

Heterogeneity of Alcohol Use Disorder: Understanding Mechanisms to Advance Personalized Treatment

THROUGHOUT THE DECADES, addiction has been viewed as a dichotomous entity-a patient either had or did not have the disorder, with nothing in-between (Miller, 1996). With research, however, it is becoming increasingly clear that alcohol use disorder (AUD) is, in fact, heterogeneous. Each patient develops an AUD based on his or her unique neurobiological makeup and lifetime experiences—a complex interaction of underlying genetic and environmental mechanisms (Dick and Kendler, 2012). This heterogeneity manifests in a continuum of severity, ranging from the occasional binge drinker to the chronic relapsing heavy drinker. This heterogeneity can be understood as a number of subphenotypes, each having its own unique profile of drinking pattern, motivation for drinking, alcohol-related consequences, and neurobiological underpinnings. Not surprisingly, given its heterogeneity, a wide variety of clinically acceptable treatment outcomes are possible with AUD, including not only abstinence, but also low-risk drinking (and even some less-conservative forms of moderate drinking; Dawson et al., 2005; Willenbring et al., 2009). This has resulted in a menu of effective treatment options (O’Malley and O’Connor, 2011; Witkiewitz and Marlatt, 2011). The U.S. Food and Drug Administration has approved 3 medications to treat alcohol dependence—disulfiram, oral and injectable naltrexone, and acamprosate—and nalmefene was approved last year by the European Medicines Agency (Mann et al., 2013; O’Malley and O’Connor, 2011). A variety of behavioral therapies have also been shown to be effective, including cognitive-behavioral therapy (CBT), motivational enhancement therapy (MET), 12-step facilitation therapy (TSF), contingency management, brief behavioral intervention, behavioral couples/family therapy, and the community reinforcement approach (Fuller and HillerSturmhoefel, 1999; Miller and Meyers, 1999; Witkiewitz and Marlatt, 2011). Unfortunately, despite the proven efficacy of these treatment approaches, given the heterogeneity of AUD, no one treatment will work for every person suffering from this complex disorder.

A Double-Blind, Placebo-Controlled Trial to Assess the Efficacy of Quetiapine Fumarate XR in Very Heavy-Drinking Alcohol-Dependent Patients

BACKGROUND Despite advances in developing medications to treat alcohol dependence, few such medications have been approved by the Food and Drug Administration. Identified molecular targets are encouraging and can lead to the development and testing of new compounds. Atypical antipsychotic medications have been explored with varying results. Prior research suggests that the antipsychotic quetiapine may be beneficial in an alcohol-dependent population of very heavy drinkers. METHODS In this double-blind, placebo-controlled trial, 224 alcohol-dependent patients who reported very heavy drinking were recruited across 5 clinical sites. Patients received either quetiapine or placebo and Medical Management behavioral intervention. Patients were stratified on gender, clinical site, and reduction in drinking prior to randomization. RESULTS No differences between the quetiapine and placebo groups were detected in the primary outcome, percentage heavy-drinking days, or other drinking outcomes. Quetiapine significantly reduced depressive symptoms and improved sleep but had no effect on other nondrinking outcomes. Results from a subgroup analysis suggest that patients who reduced their drinking prior to randomization had significantly better drinking outcomes during the maintenance phase (p < 0.0001). No significant interactions, however, were observed between reducer status and treatment group. Finally, quetiapine was generally well tolerated. Statistically significant adverse events that were more common with quetiapine versus placebo include dizziness (14 vs. 4%), dry mouth (32 vs. 9%), dyspepsia (13 vs. 2%), increased appetite (11 vs. 1%), sedation (15 vs. 3%), and somnolence (34 vs. 9%). CONCLUSIONS This multisite clinical trial showed no efficacy for quetiapine compared with placebo at reducing alcohol consumption in heavy-drinking alcohol-dependent patients.

A Double‐Blind, Placebo‐Controlled Trial Assessing the Efficacy of Levetiracetam Extended‐Release in Very Heavy Drinking Alcohol‐Dependent Patients

BACKGROUND Despite advances in the development of medications to treat alcohol dependence, few medications have been approved by the U.S. Food and Drug Administration. The use of certain anticonvulsant medications has demonstrated potential efficacy in treating alcohol dependence. Previous research suggests that the anticonvulsant levetiracetam may be beneficial in an alcohol-dependent population of very heavy drinkers. METHODS In this double-blind, randomized, placebo-controlled clinical trial, 130 alcohol-dependent patients who reported very heavy drinking were recruited across 5 clinical sites. Patients received either levetiracetam extended-release (XR) or placebo and a Brief Behavioral Compliance Enhancement Treatment intervention. Levetiracetam XR was titrated during the first 4 weeks to 2,000 mg/d. This target dose was maintained during weeks 5 through 14 and was tapered during weeks 15 and 16. RESULTS No significant differences were detected between the levetiracetam XR and placebo groups in either the primary outcomes (percent heavy drinking days and percent subjects with no heavy drinking days) or in other secondary drinking outcomes. Treatment groups did not differ on a number of nondrinking outcomes, including depression, anxiety, mood, and quality of life. The only difference observed was in alcohol-related consequences. The levetiracetam XR treatment group showed significantly fewer consequences than did the placebo group during the maintenance period (p = 0.02). Levetiracetam XR was well tolerated, with fatigue being the only significantly elevated adverse event, compared with placebo (53% vs. 24%, respectively; p = 0.001). CONCLUSIONS This multisite clinical trial showed no efficacy for levetiracetam XR compared with placebo in reducing alcohol consumption in heavy drinking alcohol-dependent patients.

Clinical Validation of Reduced Alcohol Consumption After Treatment for Alcohol Dependence Using the World Health Organization Risk Drinking Levels

Background Alcohol use disorder (AUD) is a highly prevalent public health problem associated with considerable individual and societal costs. Abstinence from alcohol is the most widely accepted target of treatment for AUD, but it severely limits treatment options and could deter individuals who prefer to reduce their drinking from seeking treatment. Clinical validation of reduced alcohol consumption as the primary outcome of alcohol clinical trials is critical for expanding treatment options. One potentially useful measure of alcohol treatment outcome is a reduction in the World Health Organization (WHO, International Guide for Monitoring Alcohol Consumption and Related Harm. Geneva, Switzerland, 2000) risk levels of alcohol use (very high risk, high risk, moderate risk, and low risk). For example, a 2‐shift reduction in WHO risk levels (e.g., high risk to low risk) has been used by the European Medicines Agency (2010, Guideline on the Development of Medicinal Products for the Treatment of Alcohol Dependence. UK) to evaluate nalmefene as a treatment for alcohol dependence (AD; Mann et al. 2013, Biol Psychiatry 73, 706–13). Methods The current study was a secondary data analysis of the COMBINE study (n = 1,383; Anton et al., 2006) to examine the association between reductions in WHO risk levels and reductions in alcohol‐related consequences and mental health symptoms during and following treatment in patients with AD. Results Any reduction in WHO risk drinking level during treatment was associated with significantly fewer alcohol‐related consequences and improved mental health at the end of treatment and for up to 1 year posttreatment. A greater reduction in WHO risk drinking level predicted a greater reduction in consequences and greater improvements in mental health. Conclusions Changes in WHO risk levels appear to be a valid end point for alcohol clinical trials. Based on the current findings, reductions in WHO risk drinking levels during treatment reflect meaningful reductions in alcohol‐related consequences and improved functioning.

Posttreatment low-risk drinking as a predictor of future drinking and problem outcomes among individuals with alcohol use disorders.

BACKGROUND Treatment for alcohol disorders has traditionally been abstinence-oriented, but evaluating the merits of a low-risk drinking outcome as part of a primary treatment endpoint is a timely issue given new pertinent regulatory guidelines. This study explores a posttreatment low-risk drinking outcome as a predictor of future drinking and problem severity outcomes among individuals with alcohol use disorders in a large private, not for profit, integrated care health plan. METHODS Study participants include adults with alcohol use disorders at 6 months (N = 995) from 2 large randomized studies. Logistic regression models were used to explore the relationship between past 30-day drinker status at 6 months posttreatment (abstinent [66%], low-risk drinking [14%] defined as nonabstinence and no days of 5+ drinking, and heavy drinking [20%] defined as 1 or more days of 5+ drinking) and 12-month outcomes, including drinking status and Addiction Severity Index measures of medical, psychiatric, family/social, and employment severity, controlling for baseline covariates. RESULTS Compared to heavy drinkers, abstinent individuals and low-risk drinkers at 6 months were more likely to be abstinent or low-risk drinkers at 12 months (adj. ORs = 16.7 and 3.4, respectively; p < 0.0001); though, the benefit of abstinence was much greater than that of low-risk drinking. Compared to heavy drinkers, abstinent and low-risk drinkers were similarly associated with lower 12-month psychiatric severity (adj. ORs = 1.8 and 2.2, respectively, p < 0.01) and family/social problem severity (adj. OR = 2.2; p < 0.01). While abstinent individuals had lower 12-month employment severity than heavy drinkers (adj. OR = 1.9; p < 0.01), low-risk drinkers did not differ from heavy drinkers. The drinking groups did not differ on 12-month medical problem severity. CONCLUSIONS Compared to heavy drinkers, low-risk drinkers did as well as abstinent individuals for many of the outcomes important to health and addiction policy. Thus, an endpoint that allows low-risk drinking may be tenable for individuals undergoing alcohol specialty treatment.

Potential medications for the treatment of alcohol use disorder: An evaluation of clinical efficacy and safety.

Alcohol use disorder (AUD), as currently defined in the Diagnostic and Statistical Manual, 5th Edition (DSM-5), is a heterogeneous disorder stemming from a complex interaction of neurobiological, genetic, and environmental factors. As a result of this heterogeneity, there is no one treatment for AUD that will work for everyone. During the past 2 decades, efforts have been made to develop a menu of medications to give patients and clinicians more choices when seeking a therapy that is both effective and which has limited side effects. To date, 3 medications have been approved by the US Food and Drug Administration (FDA) to treat alcohol dependence: disulfiram, naltrexone, and acamprosate. In addition to these approved medications, researchers have identified new therapeutic targets and, as a result, a number of alternative medications are now being evaluated for treatment of AUD in human studies. Although not approved by the FDA for the treatment of AUD, in some cases, these alternative medications are being used off-label by clinicians for this purpose. These potential medications are reviewed here. They include nalmefene, varenicline, gabapentin, topiramate, zonisamide, baclofen, ondansetron, levetiracetam, quetiapine, aripiprazole, and serotonin reuptake inhibitors. The effectiveness of these medications has been mixed-some show good efficacy with side effects that are mild to moderate in intensity; others have mixed or promising results but are awaiting findings from ongoing studies; and still others show poor efficacy, despite promising preliminary results. Medications development remains a high priority. Key initiatives for the National Institute on Alcohol Abuse and Alcoholism (NIAAA) include supporting the discovery and development of more effective and safer medications, advancing the field of personalized medicine, and forging public and private partnerships to investigate new and more effective compounds.

Moderators of Varenicline Treatment Effects in a Double-Blind, Placebo-Controlled Trial for Alcohol Dependence: An Exploratory Analysis.

Objectives:To explore whether varenicline (Chantix) showed more efficacy in treating certain subgroups of patients. In a recent multisite trial, varenicline was shown to be effective in reducing drinking in alcohol-dependent patients, both smokers and nonsmokers. Given the heterogeneity among alcohol-dependent patients, secondary analyses were conducted to determine whether certain subgroups responded more favorably than others to treatment with varenicline. Methods:Data were drawn from a phase 2 randomized, double-blind, placebo-controlled multisite 13-week trial of varenicline in alcohol-dependent patients (Litten et al., 2013). Seventeen moderator variables were selected for exploratory testing on the basis of theoretical and scientific interest. Results:Of the 17 moderator variables assessed, 4 were statistically significant, including cigarettes per day reduction, treatment drinking goal, years drinking regularly, and age of the patient. Two other variables—the type of adverse events experienced by patients and the severity of alcohol-related consequences—seemed to moderate the varenicline treatment effect at borderline statistical significance. Individuals who reduced the number of cigarettes per day experienced a significant effect from varenicline in reducing drinking, whereas those who did not change or who increased their number of cigarettes observed no beneficial effect. Reviewing the moderators related to severity, varenicline seemed to have greater efficacy than placebo among less severely dependent patients. Conclusions:Varenicline seems to be more efficacious in certain subgroups, particularly in those who reduced their smoking and in the “less severe” patient. Additional studies are warranted to confirm the results of these exploratory analyses.

A Phase 2, Double-Blind, Placebo-Controlled Randomized Trial Assessing the Efficacy of ABT-436, a Novel V1b Receptor Antagonist, for Alcohol Dependence

Alcohol use disorder has been linked to dysregulation of the brain stress systems, producing a negative emotional state leading to chronic relapsing behavior. Vasopressin receptors appear to have a regulatory role in stress, anxiety, and alcohol. This study evaluated the novel compound, ABT-436, a V1b receptor antagonist, in alcohol-dependent participants in a 12-week clinical trial. Men and women (n=150) who met criteria for DSM–IV alcohol dependence were recruited across four sites. Participants received double-blind ABT-436 or placebo, and a computerized behavioral intervention. ABT-436 was titrated to 800 mg/day during weeks 2–12. Although the primary outcome, percentage of heavy drinking days, was lower in participants receiving ABT-436 compared with placebo, this difference was not statistically significant (31.3 vs 37.6, respectively; p=0.172; d=0.20). However, participants receiving ABT-436 had significantly greater percentage of days abstinent than those receiving placebo (51.2 vs 41.6, respectively; p=0.037; d=0.31). No significant differences were found between treatment groups on any other measures of drinking, alcohol craving, or alcohol-related consequences. Smokers receiving ABT-436 smoked significantly fewer cigarettes per week than those receiving placebo (p=0.046). ABT-436 was well tolerated, with diarrhea (mild-to-moderate severity) being the most common side effect. In subgroup analyses, participants with relatively higher baseline levels of stress responded better to ABT-436 than placebo on select drinking outcomes, suggesting there may be value in testing medications targeting the vasopressin receptor in high stress, alcohol-dependent patients.