INTRODUCTION: The RECOVER (Remission from Chronic Opioid Use: Studying Environmental and SocioEconomic Factors on Recovery, NCT03604861) study explores outcomes in people with opioid use disorder (OUD) who initiated their recovery journey through participation in a Phase III study evaluating buprenorphine extended-release monthly injection (BUP-XR). The objectives are to characterize opioid abstinence over a 24-month observational window; examine clinical, environmental, and socioeconomic factors associated with opioid abstinence and relapse; and understand the long-term effects of BUP-XR treatment on clinical, humanistic, and economic outcomes in OUD. This analysis focuses on cumulative and past-week opioid abstinence during the first 12 months of the observational window.
METHODS: Participants could enroll in RECOVER 28 days after completing or discontinuing participation in a BUP-XR Phase III study, comprising a double-blind, randomized, placebocontrolled trial (NCT02357901) and an open-label safety study (NCT02510014). Three data sources inform the RECOVER analyses: a self-administered assessment completed every 3 months; urine drug screen (UDS) completed every 3 months; and publicly available information obtained from multiple sources at various times. Self-assessments were used to collect data on past week, past month, and past 6-month opioid use. Cumulative opioid abstinence over 12 months and past-week point-prevalent abstinence by BUP-XR treatment duration groups were evaluated descriptively. Multivariate models were used to control for treatment duration, demographics, drug use history and treatment, time since last BUP-XR dose, state-level opioid treatment policy indexes, and pre-Phase III study BUP-XR treatment differences.
RESULTS: The RECOVER study includes 533 participants. Approximately half (50.8%) self-reported abstinence for 12-months following their last study injection; 20.3% reported receiving pharmacologic therapy for a substance use disorder during RECOVER. Past-week, self-reported opioid abstinence was noted on 68.0% of assessments. Longer BUP-XR treatment duration was associated with higher complete opioid abstinence over the 12-month period. Continuous 12-month abstinence was reported by 62.7% of participants receiving BUP-XR for 12 months compared with 32.1% of participants receiving BUP-XR for ≤2 months. After adjustment, 12-month compared with ≤2-month BUP-XR treatment duration remained a significant predictor of opioid abstinence over the 12-month period (75.3% vs 24.1%; P=0.001). Models of past week self-reported abstinence suggested that the adjusted likelihood of abstinence at 12 months was 82.1% (95%CI:72.7%-88.7%) for those who stayed on BUP-XR for 12 months, 70.8% (59.9%-79.7%) for 6- 11 months, 48.8% (41.5%-56.2%) for 3-5 months, and 58.6% (44.5%-71.3%) for ≤2 months. When combining self-reported past-week abstinence with UDS outcomes, the adjusted likelihood of past week abstinence at 12 months for those who stayed on BUP-XR for 12 months was 62.4% (47.0%-75.7%), 6-11 months 49.8% (38.2%-61.4%), 3-5 months 36.9% (29.9%-44.5%), and ≤2 months 35.6% (24.6%-48.5%).
CONCLUSION: Within the 12 months following RECOVER enrollment, half of participants self-reported complete abstinence, despite the low prevalence of additional pharmacologic OUD treatments. Longer BUP-XR treatment durations were associated with higher rates of opioid abstinence over 12- months and past-week opioid use, as measured by self-report and self-report plus UDS results. These findings provide important insights into understanding the role of novel pharmacologic treatments in supporting a patient’s recovery.
