Effects of a novel GABA-B positive allosteric modulator, ASP8062, on alcohol cue-elicited craving and naturalistic alcohol consumption in a multisite randomized, double-blind, placebo-controlled trial

Background

The γ-aminobutyric acid-B (GABA_B) receptor is a promising target for the development of new medications to treat alcohol use disorder (AUD). The GABA_B agonist baclofen has been reported to reduce alcohol consumption but is associated with some undesirable side effects, including sedation. ASP8062 is a novel compound that acts as a positive allosteric modulator at the GABA_B receptor and may be more tolerable than baclofen. This proof-of-concept human laboratory clinical trial evaluated the safety profile of ASP8062 and tested its effects on cue-elicited alcohol craving and alcohol use among treatment-seeking individuals with AUD.

Methods

This double-blind, randomized, multisite trial tested the effect of ASP8062 (25 mg once daily), relative to placebo, on alcohol cue-elicited craving in a laboratory setting and alcohol consumption, craving, mood, sleep, cigarette smoking, and alcohol-related consequences in the natural environment over a 6-week treatment period. Participants were 60 individuals (26 females and 34 males) with moderate or severe AUD.

Results

ASP8062, relative to placebo, was well tolerated, and there were no adverse events (AEs) that significantly differed between treatment groups. Most AEs were mild/moderate, and there were no serious AEs among individuals treated with ASP8062. However, ASP8062 did not attenuate alcohol cue-elicited craving compared with placebo. Moreover, exploratory analyses indicated that ASP8062, relative to placebo, did not significantly affect alcohol consumption, naturalistic alcohol craving, mood, sleep, cigarette smoking, or alcohol-related negative consequences during the 6-week treatment period.

Conclusions

Although ASP8062 was well tolerated with no serious AEs, the novel compound did not significantly dampen alcohol cue-elicited craving or improve other AUD-related outcome measures. These data indicate positive allosteric modulation of the GABA_B receptor at the dose evaluated here may not blunt alcohol cue-elicited craving, and preliminary drinking outcome data suggest it may not be an efficacious treatment strategy for AUD.