Evolving trends in Latin American oncology clinical trial sites.

e23155 Background: The globalization of oncology trials has created opportunities for emerging regions to play larger roles in clinical research. This study evaluated trends in the establishment of new trial sites in Latin America (LATAM) compared to other regions and assessed participant representation. Methods: We analyzed phase 3 oncology trials posted on ClinicalTrials.gov from January 2013 to December 2022. Trials with at least one newly initiated LATAM site, defined by the date of first participant enrollment, were included. Data on site distribution, cancer types, interventions, control types, and demographics were collected, with regions classified by World Bank criteria. Site proportions were calculated using descriptive statistics, and growth trends were assessed with the Mann-Kendall test. Results: The year 2022 was excluded from the trend analysis due to limited data. A total of 172 trials (29,718 sites, 120,582 participants) were analyzed. LATAM contributed 2,609 sites (8.8%) across 10 countries, led by Brazil (n = 1,194, 4%), Argentina (n = 485, 1.6%), and Mexico (n = 339, 1.1%). Hispanic participants were reported in 99 trials (57.6%). Over the 9-year period, new LATAM sites showed a significant upward trend (p = 0.04), while North America declined (p &lt; 0.01) and Asia increased (p &lt; 0.01). Regionally, new sites in Brazil decreased over time (p = 0.03), with no sustained trends in other LATAM countries. The most frequently studied cancers were breast (n = 623, 23.9% of LATAM sites), lung (n = 611, 23.4%), and prostate (n = 472, 18.1%). Immunotherapy accounted for most new LATAM sites (n = 922, 35.5%), followed by targeted therapies (n = 565, 21.7%), biologic therapies (n = 277, 10.6%), hormone therapies (n = 262, 10%), PARP inhibitors (n = 144, 5.5%), and antibody-drug conjugates (n = 67, 2.5%). Other therapies contributed 9.7% (n = 254) of new sites. Trials primarily used double-arm active comparators (n = 1,395, 54%), followed by placebo-controlled designs (n = 1,006, 38%), and multi-arm designs (n = 208, 8%). Conclusions: Nearly half of LATAM trials lacked Hispanic participant data, suggesting underreporting or limited standardization in reporting. The growth of new trial sites across the region was not concentrated in a single country, suggesting increasing contributions from smaller nations. Brazil accounted for the majority of trial sites, likely due to its stronger economic environment, more developed healthcare infrastructure, and larger population, which facilitate trial initiation and participant recruitment. Further research is needed to analyze global trends and factors driving these shifts. New LATAM trial sites per year. 2013 2014 2015 2016 2017 2018 2019 2020 2021 Argentina 48 74 60 19 54 61 123 37 9 Brazil 166 128 215 93 206 152 127 94 13 Chile 15 25 41 18 22 33 51 24 1 Colombia 9 16 32 - 10 18 41 13 - Costa Rica - 1 2 - 5 7 1 - - El Salvador 1 1 - - - - - - - Guatemala 3 4 1 - 5 9 - - 5 Mexico 30 65 66 16</j