Enrollment outcomes after screening in phase 1 oncology clinical trials: Real-world evidence from a NCI-designated cancer center.

Abstract

e13720 Background: Despite many efforts to increase diversity enrollment in Phase 1 trials (Ph1) significant disparities persist among underrepresented minorities (URM). Enrollment patterns for this patient population after initial screening for Ph1 are poorly understood. We evaluated the patients' journey from screening to enrollment for URM to understand the patterns once they have potential access to Ph1. Methods: All patients screened for Ph1 at the John Theurer Cancer Center at Hackensack University Medical Center from 2014-2025 were analyzed. Primary outcomes were enrollment rate, stratification by racial/ethnic group and representation compared to US Census Bureau (2018-2022). Statistical analysis included a chi-square test for differences in enrollment rates, Fisher's exact test for pairwise comparisons, and a Kruskal-Wallis test for age differences. Results: A total of 1,316 patients were evaluated for 140 Ph1. 803 patients were enrolled, yielding an enrollment rate of 61.0%, with URM comprising 33.3% of enrollments. The study cohort was 52.1% female and 47.9% male, median age was 62.5 years (range, 24.7–90.9). Racial/ethnic composition included non-Hispanic White (NHW) 66.2%, Hispanic 19.0%, African American/Black (AA) 7.5%, Asian 6.8%, and Other 0.5%.There were no statistically significant differences in enrollment rates across groups (p=0.225). However, NHW had higher enrollment rates compared to URM. NHW 62.6%, Hispanic 60.8%, AA 56.9%, Asian 52.3%. Pairwise comparisons are shown in Table 1. Comparison with census data demonstrated notable disparities in representation. NHW participants were overrepresented at screening (66.2% vs 47%; ratio 1.42), whereas URM groups were underrepresented, including Hispanic (19.0% vs 20%; ratio 0.95), AA (7.5% vs 14%; ratio 0.52), and Asian individuals (5.6% vs 10%; ratio 0.56). The enrollment rate remained stable over time (2014-2019: 59.6% vs 2020-2024: 63.5%, p=0.907). Mean age in the study cohort varied significantly (Kruskal-Wallis H=62.68, p<0.001): Hispanic 58.5 years, AA 59.5 years, Asian 59.5 years, NHW 64.2 years, with Hispanic being the youngest group to enroll. Conclusions: Enrollment rates among patients screened for Ph1 were comparable across racial/ethnic groups, indicating equitable access after screening. However, substantial demographic disparities were observed at the screening stage with NHW being overrepresented, and AA and Asian patients underrepresented relative to regional demographics. These findings suggest that ensuring access to Ph1 access enables enrollment parity, but that inequities in referral and pre-screening processes persist. Comparison Rates P-valve NHW / Hispanic 62.6% / 60.8% p = 0.606 NHW / AA 62.6% / 56.9% p = 0.282 NHW / Asian 62.6% / 52.3% p = 0.064 Hispanic / AA 60.8% / 56.9% p = 0.550 Hispanic / Asian 60.8% / 52.3% p = 0.204 AA / Asian 56.9% / 52.3% p = 0.559