PROJECT SUMMARY / ABSTRACT Ending the HIV epidemic requires achieving HIV viral load (HVL) suppression for key populations. Unhealthy alcohol use by people with HIV (PWH) is a barrier to reaching HVL suppression at multiple stages of the HIV care cascade. Alcohol use is common among PWH and results in lower antiretroviral therapy (ART) adherence and HVL suppression, mitigating the effectiveness of Treatment as Prevention (TasP), a key strategy for preventing HIV transmission. Treating alcohol use is therefore a mechanism to support PWH with unhealthy alcohol use along the HIV care cascade. In fact, prior studies demonstrate that interventions to reduce alcohol use positively impact HIV outcomes. Gabapentin is efficacious for decreasing alcohol consumption and may be an effective treatment for painful conditions, such as HIV-associated sensory neuropathies. However, gabapentin’s role in achieving HVL suppression in this population has not been established. Our hypothesis is that effective pharmacological alcohol treatment (i.e., gabapentin) will help PWH engage in HIV care, adhere to ART, and achieve HVL suppression. We propose the Gabapentin to Reduce Alcohol and Improve Viral Load Suppression (GRAIL) randomized, double-blinded, placebo-controlled clinical trial to evaluate the efficacy of gabapentin vs. placebo to achieve HVL suppression among PWH. The study population will be heavy drinkers with HIV who had a detectable viral load in the past year, despite having been prescribed ART. Participants (N=300) will be randomized 1:1 to receive either gabapentin (1800mg/day target dose) or placebo for 3 months; both arms will employ a one-time brief intervention to reduce alcohol use. GRAIL aims to 1) test the efficacy of gabapentin versus placebo to achieve undetectable HVL at 3 months (primary outcome) and at 6 & 12 months (secondary outcomes); and 2) to assess the impact of gabapentin compared to placebo on: a) alcohol consumption, b) pain severity, c) self-reported ART adherence, and d) engagement in HIV care, in order to explore potential mechanisms by which gabapentin may lead to HVL suppression. This study will take place in Russia, in a context of syndemic unhealthy alcohol use, drug use, and HIV. Our multi-disciplinary team has an extensive track record of successfully conducting randomized clinical trials in Russia, including pharmacological trials (e.g., gabapentin) in PWH. Russia, a setting in which HIV and heavy alcohol use are more prevalent than in the US, will enable efficient study of intervening on alcohol use among PWH. The knowledge gained will be applicable to populations living with HIV in the US and globally. The proposed trial of gabapentin is significant as it employs a TasP approach to prevent transmission of HIV by targeting alcohol use and achieving HVL suppression. If shown to be effective, this highly generalizable pragmatic approach to TasP can be implemented in a variety of clinical settings, thus making it a practical addition to the HIV prevention toolkit.

PROJECT NARRATIVE The GRAIL trial will assess the efficacy of gabapentin versus placebo for improving HIV viral load suppression among people with HIV (PWH) and heavy alcohol use on ART as a “Treatment as Prevention” strategy. If shown to be effective, this will be a potent addition to the HIV prevention toolkit to address HIV transmission from PWH with heavy alcohol use in Russia, the US, and globally.