Evaluation of Tirzepatide as an Adjunct to Buprenorphine for the treatment of opioid use disorder (TAB) trial: study design and rationale.

Buprenorphine treatment for opioid use disorder (OUD) is highly effective in decreasing opioid use, risk of opioid overdose, and death, but retention is challenging. Buprenorphine does not always eliminate illicit opioid use and craving and does not treat stimulant or other substance co-use, nor common comorbid sleep problems. Tirzepatide, a glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptor agonist, may help address substance use and sleep problems. The National Drug Abuse Treatment Clinical Trials Network (CTN) is conducting a 9-site outpatient, intent-to-treat, two-arm, double-blind, randomized controlled trial: Evaluation of Tirzepatide as an Adjunct to Buprenorphine for the treatment of OUD (TAB). The primary objective is to evaluate the effect of tirzepatide, relative to placebo, as an adjunct to buprenorphine on retention and on substance-related and sleep outcomes in adults with OUD. The primary outcome is 6-month buprenorphine treatment retention. The key secondary outcome is proportion of illicit opioid-negative urine samples over the 6-month treatment period. Approximately 310 adults with moderate-severe OUD who recently started buprenorphine will be recruited and randomized 1:1 to tirzepatide or placebo, balancing on site and buprenorphine formulation (transmucosal vs extended-release). Participants will be administered study medication, receive Fitbits to track sleep, and attend weekly research visits through 6 months post-randomization with longer research visits occurring at 1, 3, and 6 months. A follow-up visit at week 30 will collect final safety measures. This paper describes the rationale and study design for TAB, the first randomized trial to test tirzepatide for the treatment of OUD.