Abstract 4346502: Unequal Access: Socioeconomic Deprivation Associated with Increased Travel Distance to Phase III Lipid-Lowering Drug Trials in the Southern United States

Abstract

Background: Early adoption of PCSK9 monoclonal antibodies and small-interfering RNA therapies depends on clinical-trial access. Yet communities with the highest cardiovascular burden—often socioeconomically deprived—are under-represented in lipid-lowering trials. Hypothesis: In the Southern U.S, Phase III lipid-lowering trial sites cluster near socioeconomically advantaged cities, forcing residents of more deprived cities to travel farther to participate. Aim: Quantify association between city-level socioeconomic deprivation and drive time to the nearest Phase III trial site. Methods: We conducted a cross-sectional geospatial analysis of Phase III trials for Inclisiran, Evolocumab, and Alirocumab initiated between 2015-2020. Trial locations were extracted from ClinicalTrials.gov, geocoded, and de-duplicated. All Census-defined Southern U.S cities with ≥50,000 residents in 2020 were included (n=284). Socioeconomic deprivation was measured with the Area Deprivation Index (ADI; higher=greater deprivation). Typical drive time from each city center to nearest trial site was computed using Google Distance Matrix API. Minority-majority status (≥50% racial minority) served as a covariate. Generalized Estimating Equations with a gamma distribution and log link, clustered by city, estimated percent change in drive time per one-point ADI increment. Results: Of the 284 cities in the study, 151 (53%) were minority-majority. 73 cities (26%) contained a trial site and yielded 849 city–site dyads. Median drive time was 36 min (IQR 21–91); 58% of cities required ≥30 min and 38% ≥60 min of travel. Each one-point ADI increase was associated with a 2.1% longer drive time (β=0.0212, 95% CI 0.017–0.025; p<0.001). Moving from the 25th to the 75th ADI percentile more than doubled predicted travel burden. After adjustment, minority-majority cities had a 21.7% shorter drive time than non-minority-majority cities (β = -0.245, 95% CI -0.438 to -0.053; p=0.013), reflecting concentration of sites in a few large, diverse hubs. Results were robust to driving distance, PCSK9 inhibitor-only analyses, and city-level clustering. Conclusions: Southern U.S cities with greater socioeconomic deprivation face substantially longer travel times to Phase III lipid-lowering clinical trials, potentially limiting early therapeutic access and perpetuating evidence gaps. Strategic placement of future trial sites in deprived areas is essential for equity and generalizability in cardiovascular drug development.