MRI-2594

MRI-2594 is a potent and highly selective small molecule agonist of the cannabinoid CB2 receptor (CB2R). It exhibits a high binding affinity (Ki = 0.031 nM) and functional potency (EC50 = 0.09 nM) for the human CB2R, with greater than 1800-fold selectivity over the CB1 receptor. Developed by researchers within the National Institutes of Health (NIH) intramural programs (specifically NIDA and NIAAA), MRI-2594 is being investigated as a novel, non-opioid pharmacotherapy for opioid use disorder (OUD). Preclinical studies in rodents have demonstrated that MRI-2594 significantly reduces heroin self-administration and heroin-primed reinstatement of drug-seeking behavior. Its mechanism involves the modulation of the mesolimbic dopamine system, where it inhibits dopamine release in the nucleus accumbens. Unlike CB1 receptor ligands, MRI-2594 does not produce psychoactive effects, sedation, or motor impairment, and it provides modest analgesia without compromising the efficacy of therapeutic opioids like oxycodone.