Extending the Prevention Toolbox: Exploring the Acceptability and Impact of Long-acting Injectable PrEP among MSM in Baltimore: A Pilot Study - PROPOSAL SUMMARY The incidence of HIV in Baltimore, MD is among the highest in the US, with men who have sex with men (MSM) bearing a disproportionate burden of the disease. As we enter the “95-95-95” era of the Joint UN Program on HIV/AIDS (UNAIDS) Fast Track targets, research into innovative approaches that extend the prevention toolbox is needed. Long-acting (LA) cabotegravir (CAB) for HIV pre-exposure prophylaxis (PrEP) was recently approved by the FDA based on data that demonstrated superiority to tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC). LA PrEP may help overcome key challenges of oral PrEP by increasing PrEP use/uptake, particularly among key populations, such as MSM. Furthermore, much research has shown that social and structural determinants of health (SSDoH), such as poverty, racism, access, homonegativity and discrimination and individual and community-level factors, such as stigma, knowledge, and perception towards PrEP shape access and uptake of PrEP among MSM individuals. Studies to date have explored the acceptability of LA PrEP as a hypothetical option among MSM; however, since the FDA approval of LA CAB in December 2021, little is known about perceptions and acceptability of LA PrEP in high-risk MSM communities and its relation to sexual network structures (e.g., how do the perceptions and behaviors of one’s contacts influence one’s own perception of LA PrEP). Further, even among those on oral PrEP, little is known about the knowledge, acceptability, and preference of daily tenofovir alafenamide (TAF) vs. TDF-based regimens and further still, daily oral PrEP vs. TDF/FTC 2-1-1 (on-demand) PrEP, which was not included in CDC guidelines until 2021. The applicants proposed study, Extending the Prevention Toolbox: Exploring the Acceptability and Impact of Long-acting Injectable PrEP among MSM in Baltimore: A Pilot Study will address this gap. This study will gather data on community preferences for PrEP choices among MSM in Baltimore and use this information to inform messaging and support mechanisms, as well as generate data on behaviors and networks to inform epidemiological models and policies to reduce barriers to PrEP. This will be accomplished through the following aims: Aim 1: To use thematic analysis from the parent study focus group interviews, to refine a cross-sectional survey including a DCE module for PrEP preferences with random allocation of attributes (i.e., cost, side-effects, effectiveness, insurance coverage etc.) within each PrEP choice set. Aim 2: To characterize MSM sexual networks in Baltimore (N=500) to determine the impact of predisposing, enabling, and perceived need factors on PrEP use/uptake. Aim3: To evaluate how sexual network characteristics impacts PrEP use/uptake and preferences among MSM; H1: The use/uptake of PrEP is positively associated with PrEP use within sexual networks and H2: PrEP preferences, as determined in the DCE are positively associated with sexual network partner preferences. This innovative study builds on over many months of preliminary work of conducting focus groups and qual data analysis for the parent study. It establishes a foundation for future studies to evaluate the role of LA PrEP in MSM communities to implement an informed PrEP strategy.