A Study of Adult Outpatients With Opioid Dependence Transitioned From a Daily SL Buprenorphine to Probuphine® Subdermal Implants (PRO-814)

Inclusion Criteria:

1. Subject must provide written informed consent prior to the conduct of any study-related procedures.
2. Male or female, 18-65 years of age, inclusive.
3. Primary diagnosis of opioid dependence (DSM-IV-TR).

4. Subject is considered clinically stable by their treating healthcare provider and confirmed by the following:

   1. Subject must be on SL BPN treatment for at least 6 months.
   2. Subject must have been on a SL BPN dose of 8 mg or less daily for at least the last 90 days prior to Screening.
   3. No positive urine toxicology results for illicit opioids in the last 90 days.
5. Free from significant withdrawal symptoms (score of ≤ 5 on the Clinical Opiate Withdrawal Scale [COWS]), as measured at the Screening Visit.
6. Female subjects of childbearing potential must be willing to use a reliable method of contraception during the entire study (Screening Visit to Follow-Up Visit).

Exclusion Criteria:

1. Current diagnosis of Acquired Immune Deficiency Syndrome (AIDS).
2. Current diagnosis of chronic pain syndrome requiring chronic opioid treatment, or conditions associated with acute episodic flares that require opioid treatment.
3. Pregnant or lactating or planning to become pregnant during the study.
4. Hypersensitivity or allergy to ethylene vinyl acetate (EVA)-containing substances or naloxone.
5. Recent scarring or tattoos on their upper arms, or a history of keloid scarring.
6. Requires current use of agents metabolized through CYP 3A4 such as azole antifungals (e.g., ketoconazole), macrolide antibiotics (e.g., erythromycin), or protease inhibitors (e.g., ritonavir, indinavir, and saquinavir).
7. History of coagulopathy within the past 90 days, and/or current anti-coagulant therapy such as warfarin.
8. Current DSM-IV-TR diagnosis for substance dependence on any other psychoactive substances other than opioids or nicotine (e.g., alcohol, cocaine).
9. Significant symptoms or other factors which in the opinion of the Investigator would preclude compliance with the protocol, subject safety, adequate cooperation in the study, or obtaining informed consent.
10. Current medical conditions such as severe respiratory insufficiency that may prevent the subject from safely participating in study.
11. Any pending legal action that could prohibit participation or compliance in the study.
12. Exposure to any investigational drug within the 8 weeks prior to Screening.
13. Aspartate aminotransferase levels ≥3 X the upper limit of normal, alanine aminotransferase levels ≥ 3 X the upper limit of normal, total bilirubin ≥ 1.5 X the upper limit of normal, or creatinine ≥ 1.5 X upper limit of normal on the Screening laboratory assessments.
14. Clinically significant low platelet count on the Screening laboratory assessments, according to the Investigator.