Medical Research.com Interview with:
Dr. Christian Heidbreder, PhD
Chief Scientific Officer
Richmond, VA 23235, USA
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: This pivotal Phase 3 clinical trial (RB-US-13-0001) evaluated the efficacy and safety of RBP-6000, an investigational once-monthly injectable buprenorphine in the ATRIGEL® delivery system for the treatment of adults with moderate-to-severe opioid use disorder (OUD) as part of a complete treatment plan to include counseling and psychosocial support1.
The 24-week Phase 3 study met its primary and key secondary endpoints, demonstrating statistically significant differences in percentage abstinence and treatment success across both dosage regimens of RBP-6000 versus placebo1.
The findings also showed that outcomes with RBP-6000 are consistent across other secondary clinical endpoints, including control of craving and withdrawal symptoms, as compared to placebo. These outcomes were associated with buprenorphine plasma concentrations ≥ 2 ng/mL and predicted whole brain mu-opioid receptor occupancy of ≥ 70%, and were also maintained for the one-month dosing intervals and for the entire treatment duration1.
The results were confirmed by exposure-response analyses demonstrating a relationship between buprenorphine plasma concentrations, abstinence, withdrawal symptoms and opioid craving1.
RBP-6000 was generally well tolerated and had a safety profile consistent with that of transmucosal buprenorphine. Injection site reactions were not treatment-limiting. The most common (reported in ≥ 5% of subjects) treatment-emergent adverse events (TEAEs) reported in the active total group were constipation, headache, nausea, injection site pruritus, vomiting, increased hepatic enzyme, fatigue and injection site pain1.