The study is being conducted to assess the effect of multiple doses of BMS-663068 on the exposure of methadone in subjects on a stable dose of methadone, and the exposure of buprenorphine and norbuprenorphine in subjects on a stable dose of buprenorphine and norbuprenorphine.

Inclusion Criteria:

1. Signed Informed Consent
2. Target population: Subjects on methadone maintenance therapy (for inclusion in Part 1) or buprenorphine and norbuprenorphine maintenance therapy (for inclusion in Part 2), who have been reliably participating in an oral methadone or buprenorphine and norbuprenorphine program and who are on a stable dose for at least 30 days prior to study screening
3. Male and Female Subjects with body mass index of 18 to 34 kg/m2, inclusive
4. Women of child bearing potential (WOCBP) with negative serum or urine pregnancy test and must not be breastfeeding
5. Men and WOCBP must agree to follow instructions for contraception

Exclusion Criteria:

1. History of any chronic or acute illness, gastrointestinal disease, smoking and alcohol abuse
2. Any Gastrointestinal (GI) surgery within 4 weeks of study drug administration that could affect its absorption
3. Evidence of organ dysfunction or any clinically significant deviation from normal in physical examination, vital signs, ECG or clinical laboratory determinations beyond what is consistent with the target population.
4. History of allergy to any drugs, BMS-663068, HIV attachment inhibitors, or related compounds