Temporal trends in early-phase oncology trials in Brazil.

Abstract

e23427 Background: With improvements in regulatory frameworks, early-phase oncology research is increasingly expanding into Latin America, particularly Brazil. Beyond capacity expansion, conducting Phase I trials in Brazil enables the enrollment of a highly diverse and historically underrepresented population, potentially enhancing the generalizability of early safety and efficacy signals. This study aimed to characterize the landscape and temporal trends of early-phase oncology drug development in Brazil. Methods: We searched the ClinicalTrials.gov database from inception through December 13, 2025, for Phase I and Phase I/II clinical trials with “cancer” listed as a condition and at least one study site in Brazil. For each trial, we manually identified all listed research facilities and extracted historical version updates to determine recruitment start and end dates for each site. We calculated facility-days (number of facilities multiplied by recruitment days) for each time frame and study-days (number of studies multiplied by recruitment days) for each trial site. Temporal trends were evaluated across four periods (2005–2010, 2011–2015, 2016–2020, and 2021–2025) using Cochran–Armitage tests, while differences between periods were assessed using Kruskal–Wallis and Fisher exact tests. Results: Of 135 cancer trials identified (44 Phase I and 91 Phase I/II), duplicates, non-cancer trials, and trials whose listed locations were never recruiting were excluded. The final cohort comprised 86 trials, including 30 Phase I and 56 Phase I/II trials. A positive temporal trend was observed in both the number of trials and median facility-days across study periods, increasing from 4 trials in 2005–2010 to 9 in 2011–2015, 17 in 2016–2020, and 56 in 2021–2025. Median facility-days rose significantly from 376 days in 2005–2010 to 1.568 days in 2021–2025 (p = 0.031). Trials were predominantly concentrated in the Southeast (93%) and South (71%) regions. ICESP/HC-FMUSP was the leading site, with 11.366 days of open accrual, followed by the Instituto Nacional de Câncer with 11.174 study-days. Subgroup analysis of Phase I trials (N = 30) mirrored these trends, increasing from 2 trials in 2005–2010 to 17 in 2021–2025, with a corresponding rise in facility-days (p = 0.021). Conclusions: Early-phase oncology trials in Brazil have increased over time, particularly in the last five years, reflecting growing national capacity for early-phase clinical research and an expanding role in the global oncology drug development landscape.