Trends and characteristics of clinical trials presented in ASCO plenary sessions (2011–2025).

11024 Background: Clinical trials presented during the ASCO Annual Meeting Plenary Session (PS) represent a curated subset with high scientific and clinical impact. However, characteristics associated with PS selection and their evolution have not been comprehensively described. This study evaluates trends and trial-, sponsor-, and presenter-related characteristics of trials in PS. Methods: Trials presented in PS from 2011–2025 were analyzed. Extracted variables included tumor type, therapeutic modality, disease setting, sponsorship, primary endpoint, effect size, geographic scope, and presenter sex and affiliation. Associations between variables were evaluated using chi-square, and multivariable logistic regression analyses. Temporal trends were assessed using Cochran-Armitage trend test. Results were considered significant at α = 0.05. Results: From 2011–2025, 60 trials were presented in ASCO PS. The majority evaluated therapies for solid tumors (90%). Most common therapeutic modalities were immune checkpoint inhibitors (18%), chemotherapy (16%), and hormone therapy (13%). Most trials were conducted in the palliative (46%), followed by adjuvant setting (25%). Only 9 trials (15%) included pediatric patients. Overall, 85% of trials met their primary endpoint. Overall survival (OS), progression-free, and disease-free survival were the most used primary endpoints, with surrogate endpoints increasingly represented over time compared with OS (p < 0.001). One trial used quality of life (QoL) as primary endpoint. Mean hazard ratio was 0.68 ± 0.24. Industry-sponsored (Ind) studies accounted for 52% of PS presentations, with four sponsors responsible for 61% of Ind trials. The proportion of Ind trials significantly increased over time (p = 0.03). Ind was significantly associated with meeting the primary (p = 0.048) and use of surrogate endpoints (p = 0.008), remaining an independent predictor of both in multivariable regression (p = 0.035, β = 0.318; p = 0.033, β = 0.333). Most studies were conducted globally (61%), 12% exclusively in the United States (US), followed by Europe (10%). Among presenters, 23% were female, with female representation not changing over time. Most presenters were affiliated with institutions in the US (62%), followed by the United Kingdom (7%). In multivariable regression analysis, Ind was associated with lower odds of a female presenter (p = 0.039; β = -0.342). Conclusions: Over the past 15 years, ASCO PS have predominantly featured global, Ind trials in solid tumors, with an increasing reliance on surrogate endpoints. Ind emerged as key factor associated with trial characteristics, including endpoint selection and trial success. Female presenter inclusion, pediatric trials, and QoL endpoints remain underrepresented. These findings provide an overview of evolving trial characteristics and inform discussions on research priorities, trial design, and representation.