Probuphine (buprenorphine implant) is an investigational implant placed just below the skin containing buprenorphine (BPN). BPN is an approved treatment for opioid dependence. This is a 6-month, open-label, re-treatment study that will confirm the safety and efficacy of Probuphine in patients who have previously completed the 6-month PRO-806 study with either Probuphine, placebo or sublingual buprenorphine.

Inclusion Criteria:

• Subject has voluntarily provided written informed consent prior to conducting any study-related procedures
• Completion of 24 weeks of treatment in PRO-806
• Subject has been deemed appropriate for entry into this extension study by the investigator
• Females of childbearing potential must be willing to use a reliable means of contraception during the entire study.

Exclusion Criteria:

• An aspartate aminotransferase (AST) levels ≥ 3 X the upper limit of normal, alanine aminotransferase (ALT) 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
• A current diagnosis of chronic pain requiring opioids for treatment
• A pregnant or lactating female
• Current use of agents metabolized through Cytochrome P450 3A4 (CYP 3A4) such as azole antifungals (e.g., ketoconazole), macrolide antibiotics (e.g., erythromycin), or protease inhibitors (e.g., ritonavir, indinavir, and saquinavir)
• A history of coagulopathy within the past 90 days, and/or current anti-coagulant therapy such as warfarin
• A significant medical or psychiatric symptoms, cognitive impairment, 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
• Any current medical conditions such as severe respiratory insufficiency that may prevent the subject from safely participating in study, or any pending legal action that could prohibit participation or compliance in the study