This study will evaluate the safety and efficacy of ALKS33 (RDC-0313) compared with placebo in adults with alcohol dependence. There will be 11 study visits conducted over a period of about 4 months. The study period includes a screening visit, a 12-week treatment period, and a follow-up visit.

This is a multi-center, randomized, double-blind, placebo-controlled study. A 3-stage adaptive design will be used. Following screening, eligible subjects will be randomized equally to 1 of 4 groups (ALKS33 [RDC-0313] [1, 2.5, OR 10 mg], or matching placebo).

Inclusion Criteria:

• 18 years of age or older
• Current diagnosis of alcohol dependence, with recent heavy drinking (eg, 5 drinks per day for men and 4 drinks per day for women)
• A noncustodial stable residence and a telephone
• Women having reproductive potential must agree to use an approved method of contraception for the duration of the study
• Ability to stop drinking prior to receiving study drug

Exclusion Criteria:

• Pregnancy and/or current breastfeeding
• Past or present history of an AIDS-indicator disease
• Current dependence on any drugs (exclusive of nicotine, caffeine, or alcohol)
• Positive urine drug screen for benzodiazepines (unless used for a short-term basis during alcohol detoxification), opioids, amphetamines/ methamphetamines or cocaine at Visits 1 and 2
• Clinically significant medical condition
• Current or anticipated need for prescribed opioid medication during the study period
• Use of naltrexone within 60 days prior to screening
• Current need for antidepressants (within 30 days prior to entry)
• Participation in a clinical trial of a pharmacological agent within 30 days prior to screening
• Parole or probation or pending legal proceedings that have the potential for incarceration during the study period