Geographic patterns of site participation in randomized oncology trials sponsored by U.S.-based organizations.

Abstract

134 Background: The geographic source of patient enrollments is integral to the interpretation and generalizability of cancer clinical trial findings. For U.S. patients and policymakers, site location may affect how well findings apply to U.S. populations and care settings. However, comparisons of geographic participation patterns between academic and industry-sponsored trials are lacking. We examined site participation in randomized phase 2 and 3 oncology trials published in leading medical and oncology journals, focusing on differences between US-based academic and industry sponsors. Methods: We reviewed the literature from 2020–2025 to identify randomized phase 2 and 3 oncology trials published in high-impact journals (impact factor >20). We included only trials by US-based sponsors. Using National Clinical Trial (NCT) identifiers, trials were linked to ClinicalTrials.gov to identify participating sites. We calculated the proportion of trials with sites on each continent and the proportion of participating sites on each continent. Results: Among 6681 reviewed trials, 272 (149 industry, 123 academic sponsors) met inclusion criteria. Trials were predominantly published in JCO (n=104) and NEJM (n=57) and were conducted primarily in breast (n=39), thoracic (n=18), and prostate (n=33) cancers. Among the 149 US-based industry-sponsored trials, 144 (96.6%) included sites in Europe, 130 (87.2%) in Asia, and 115 (77.2%) in Oceania (Australia/New Zealand; Table). In comparison, among the 123 US-based academic trials, 16 (13.0%) included sites in Europe, 19 (15.4%) in Asia, and 14 (11.4%) in Oceania. Few trials in either sponsor category included sites in Africa or South America. Among industry-sponsored trials, the largest share of sites was in Europe (39.9%), followed by North America (30.5%) and Asia (19.7%). In contrast, academic trial sites were almost entirely located in North America (97.8%). Conclusions: US-based academic and industry sponsors rely on fundamentally different geographic models of evidence generation. Industry-sponsored trials had a broad international footprint; academic-sponsored trials were overwhelmingly domestically based. These differences may influence both the applicability of trial findings across health care settings and the geographic distribution of trial opportunities available to patients. Domestic and international trial site representation for US-based cancer clinical trials. Industry Academic Continent No. (%) of Trials Proportion of Total Sites (%) No. (%) of Trials Proportion of Total Sites Africa 21 (14.1) 0.4 3 (2.4) 0.0 Asia 130 (87.2) 19.7 19 (15.4) 0.2 Europe 144 (96.6) 39.9 16 (13.0) 1.6 North America 149 (100) 30.5 123 (100) 97.8 Canada 116 (77.9) 2.7 50 (40.7) 2.1 Mexico 11 (7.4) 0.1 0 (0) 0.0 U.S. 149 (100) 26.5 123 (100) 95.6 Oceania 115 (77.2) 3.8 14 (11.4) 0.3 South America 93 (62.4) 5.7 1 (0.8) 0.0