Evaluating the Abuse Potential of Lenabasum, a Selective CB2 Cannabinoid Receptor Agonist .

Background: Endocannabinoids, which are present throughout the central nervous system (CNS), can activate CB1 and CB2 receptors. CB1 and CB2 agonists exhibit broad anti-inflammatory properties, suggesting their potential to treat inflammatory diseases. However, careful evaluation of abuse potential is necessary. Methods: This study evaluated the abuse potential of lenabasum, a selective CB2 receptor agonist in participants (n=56) endorsing recreational cannabis use. Three doses of lenabasum (20, 60, and 120mg) were compared to placebo, and nabilone (3 and 6mg). The primary endpoint was the peak effect (Emax) on a bipolar Drug Liking visual analog scale (VAS). Secondary VAS and pharmacokinetic (PK) endpoints and adverse events were assessed. Results : Lenabasum was safe and well tolerated. Compared to placebo, a 20mg dose of lenabasum did not increase ratings of Drug Liking and had no distinguishable effect on other VAS endpoints. Dose-dependent increases in ratings of Drug Liking were observed with 60 and 120mg lenabasum. Drug Liking and all other VAS outcomes were greatest for nabilone 3mg and 6mg, which is a currently FDA-approved medication. Conclusions : At a target therapeutic dose (20mg), lenabasum did not elicit subjective ratings of Drug Liking. However, supratherapeutic doses of lenabasum (60 and 120mg) did elicit subjective ratings of Drug Liking compared to placebo. Although both doses of lenabasum were associated with lower ratings of Drug Liking compared to 3mg and 6mg of nabilone, suggesting that lenabasum does have abuse potential and should be used cautiously in clinical settings. Significance Statement This work provides evidence that in people with a history of recreational cannabis use, lenabasum was safe and well-tolerated, although it did demonstrate abuse potential. This work supports further development of lenabasum for potential therapeutic indications.