A monthly subcutaneous injection of RBP-600, an extended-release formulation of buprenorphine (BUP-XR), was found to be well-tolerated and effective for promoting abstinence in patients with moderate to severe opioid use disorder, according to a study published in the Lancet.
The investigators enrolled a total of 504 adults (age ≤65) from 36 treatment centers who were seeking treatment for moderate or severe opioid use disorder. This open-label run-in phase consisted of up to 2 weeks of therapy. Study participants were randomly assigned to receive BUP-XR 300 mg/300 mg (6 injections of 300 mg; n=196), BUP-XR 300 mg/100 mg (2 injections of 300 mg plus 4 injections of 100 mg; n=194), or volume-matched placebo (n=99) every 28 days. All participants also received weekly drug counselling. The study’s primary outcome was the percentage of participants abstaining from opioids as assessed by negative urine samples and self-reports of abstinence from weeks 5 to 24.
A higher percentage of patients receiving BUP-XR 300 mg/300 mg and 300 mg/100 mg vs placebo were found to abstain from opioids (41.3% and 42.7% vs 5.0%, respectively; P <.0001 for both). The most frequently reported adverse events included headache (BUP-XR 300 mg/300 mg, 8%; vs BUP-XR 300 mg/100 mg, 9%; placebo, 6%), constipation (BUP-XR 300 mg/300 mg, 8%; BUP-XR 300 mg/100 mg, 9%; placebo, 0%), nausea (BUP-XR 300 mg/300 mg, 8%; BUP-XR 300 mg/100 mg, 9%; placebo, 5%), and injection-site pruritis (BUP-XR 300 mg/300 mg, 9%; BUP-XR 300 mg/100 mg, 6%; placebo, 4%).
Study limitations include the lack of testing of patients who were unresponsive to sublingual buprenorphine-naloxone during the run-in period.
“Further research is ongoing to determine the role of this formulation in facilitating outpatient treatment for individuals who present to an emergency department,” noted the study authors. “Research is ongoing to further assess a holistic view of the long-term course of recovery in real-world clinical practice, with an emphasis on patient-centred clinical, humanistic and economic outcomes.”
Haight BR, Learned SM, Laffont CM, et al. Efficacy and safety of a monthly buprenorphine depot injection for opioid use disorder: a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial. Lancet. 2019;393:778–790.