Disparities in cancer clinical trials among low- and middle-income countries (LMIC): a 20-year analysis

Introduction: LMIC face unique challenges related to populational age transition and perspectives of soaring cancer incidence. Despite the pressing need for strong clinical research (CR) programs focusing on their unique needs, progress on this aspect appears to remain slow, unequal and too reliant on pharma-driven and late-stage clinical trials (CT). This study aims to investigate disparities in CR development among LMIC in terms of crude number and complexity of CT and to explore potential associations with level of economic growth (EG).

Methods: From the World Bank site, we identified key countries that ranked as LMIC by 2001. To document crude number, proportion of phase I-II versus III and independent versus pharma-sponsored CT, we employed search engines from clinicaltrial.gov. To investigate associations between EG and CR development, we established correlation coefficients (CC) defined as weak (0,2–0,39), moderate (0,4–0,69) or strong (0,7–0,89) based on the Pearson correlation coefficient.

Results: Between 2001–2020, 16.977 CT with access in LMIC were registered. The Asian countries China and South Korea experienced both strong EG and robust increases in crude number of CT (strong CCs). South and Southeast Asian countries had strong EG but, at best, modest increases in CT (variable CCs). Most East European countries and Middle Eastern Turkey experienced robust EG with consistent increases in CT (moderate to strong and strong CCs, respectively). South and North American largest economies (Argentina, Brazil and Mexico) had mainly inconsistent EG but consistent increases in CT (weak to moderate CCs). For African countries, Egypt (but not South Africa) showed consistent EG and increases in CT (strong and weak CCs, respectively). Except for China and South Korea, other LMIC remained largely reliant on pharma-sponsored CT and having a low proportion of phase I-II relative to phase III CT.

Conclusions: CR development has been largely unequal among LMIC. Strong EG may contribute to CR development in these countries, but only to some extent. Only China and South Korea were able meaningfully increase complexity of CR. These data reinforce the need for initiatives to support and develop academic cancer research in these regions.

Corresponding author: Fanny Gueselha de Almeida Cascelli (e-mail: fannycascelli87@gmail.com).