Efficacy and safety of a monthly buprenorphine depot injection for opioid use disorder: a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial

RBP-6000, referred to as BUP-XR (extended-release buprenorphine), is a subcutaneously injected, monthly buprenorphine treatment for opioid use disorder. BUP-XR provides sustained buprenorphine plasma concentrations to block drug-liking of abused opioids over the entire monthly dosing period, while controlling withdrawal and craving symptoms. Administration of BUP-XR in a health-care setting also mitigates abuse, misuse, diversion, and unintentional exposure. We aimed to investigate the efficacy of different BUP-XR dosing regimens in participants with opioid use disorder. This randomised, double-blind, placebo-controlled, phase 3 trial was done at 36 treatment centres in the USA. Treatment-seeking adults aged 18–65 years who had moderate or severe opioid use disorder (as defined by the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders) entered an open-label run-in phase of up to 2 weeks' treatment with buprenorphine-naloxone sublingual film. Eligible participants were then randomly assigned (4:4:1:1) with an interactive voice/web-response system to receive BUP-XR 300 mg/300 mg (six injections of 300 mg), BUP-XR 300 mg/100 mg (two injections of 300 mg plus four injections of 100 mg), or volume-matched placebo every 28 days, and received weekly individual drug counselling. No supplemental buprenorphine was allowed. The primary efficacy endpoint was participants' percentage abstinence from opioid use, defined as the percentage of each participant's negative urine samples and self-reports of illicit opioid use from week 5 to week 24, analysed in the full analysis set. Safety was assessed in all participants who received at least one dose of BUP-XR or placebo. This study is registered with ClinicalTrials.gov, number NCT02357901. From Jan 28, 2015, to Nov 12, 2015, 1187 potential participants were screened, 665 entered run-in, and 504 received BUP-XR 300 mg/300 mg (n=201), BUP-XR 300 mg/100 mg (n=203), or placebo (n=100). Mean participants' percentage abstinence was 41·3% (SD 39·7) for BUP-XR 300 mg/300 mg and 42·7% (38·5) for 300 mg/100 mg, compared with 5·0% (17·0) for placebo (p