Study Evaluating MOA-728 in Subjects on Stable Methadone Maintenance

Two Ascending Single Doses Crossover, Placebo Controlled Study of the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of MOA-728 Administered Orally to Subjects on Stable Methadone Maintenance

This is a study to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of MOA-728 in subjects on stable methadone maintenance.

Inclusion Criteria:

• History of methadone treatment for at least 1 month before day -1 at a dose of ≥ 30 mg/day, and a positive drug test result for methadone.
• Healthy as determined by the investigator on the basis of screening evaluations.

Exclusion Criteria:

• Allergy to opioids (eg, codeine, morphine, or oxymorphone) or opioid antagonists (eg, naloxone or naltrexone).
• Any significant cardiovascular, hepatic, renal, respiratory, gastrointestinal, endocrine, immunologic, dermatologic, hematologic, neurologic, or psychiatric disease.