An adaptive clinical trial design for cocaine use disorder: Extended-release amphetamine salts for early behavioral intervention non-responders

Background/aims: Cocaine use disorder (CUD) persists as a major public health problem in the United States. Response to evidence-based behavioral treatment has been shown to be predicted by dopaminergic dysfunction. Amphetamine formulations modulate dopaminergic systems and are one of the few agents with positive clinical findings but are associated with unique risks. We aimed to find a model for determining the most appropriate patients for treatment with mixed amphetamine salts-extended-release (MAS-ER) for CUD using an adaptive trial design.

Methods: We are enrolling treatment-seeking adults ages 18-60 years. All eligible participants receive bi-weekly individual counseling augmented with a computer-based intervention based on the community reinforcement approach with contingency management (CRA + CM) for 4 weeks. Participants who fail to achieve abstinence are additionally randomly assigned to 10 weeks of either MAS-ER, titrated up to 80 mg daily, or placebo. All participants complete a follow-up assessment after 12 weeks.

Results: Frequency and amount of cocaine use, cravings, retention, and quality of life will be compared between groups. The primary outcome will be having at least 3 weeks of urine toxicology-confirmed self-reported abstinence. Analyses will also be conducted to identify variables that may help identify who is more or less likely respond to the behavioral intervention during the first 4-weeks of treatment.

Conclusions: This trial more closely mimics a personalized medicine approach that is often used in clinical practice. It will help us understand who may be appropriate for psychostimulant therapy as an enhancement to evidence-based behavioral interventions, while limiting exposure to those who would respond to a psychosocial intervention alone. ClinicalTrials.gov Identifier: NCT01986075.