Title : Melanoma clinical trials across the globe: A cross-sectional analysis of site distribution and disease burden
Abstract:
Melanoma remains one of the most aggressive forms of skin cancer worldwide. Participation in clinical trials is critical for the advancement of new treatments. However, equitable access to therapies depends on the geographic distribution of clinical trial sites. Disparities in trial availability can limit participation for patients living in countries with high melanoma incidence but few research opportunities. According to the World Health Organization (WHO), Australia has the highest rate of melanoma incidence and prevalence, while New Zealand has the highest rate of melanoma mortality. These patterns raise questions about whether the availability of clinical trials aligns with the global burden of disease. The purpose of this presentation is to evaluate the global distribution of melanoma clinical trials and compare its geographic patterns with global melanoma incidence, prevalence, and mortality. On August 11, 2025 we searched ClinicalTrials.gov for interventional melanoma clinical trials that were looking for participants. Trial site locations were manually extracted from each trial and categorized by country. We selected ClinicalTrials.gov instead of the WHO’s International Clinical Trials Registry Platform (ICTRP) because ICTRP does not provide information on the number of trial sites per country, instead ICTRP lists only the countries where trials are registered. Using ClinicalTrials.gov, we were able to compile the total number of sites per country. We generated a heatmap to visually compare site distribution with WHO-reported melanoma incidence, prevalence, and mortality. A total of 6368 sites from 474 trials were identified across 58 countries. On a per million population basis, the USA had 11 sites, compared with 7 in Australia and 1 in New Zealand. Approximately 61% of sites were concentrated in the United States of America (USA), while only 3% of sites were located in Australia, and <1% of sites were located in New Zealand, despite their disproportionately high melanoma burden. A chi-square goodness-of-fit test confirmed a statistically significant mismatch between melanoma incidence and trial site distribution (p<0.001), prevalence and trial site distribution (p<0.001), and mortality and trial site distribution (p<0.001). To address the mismatch between disease burden and research opportunities, there is a need to expand melanoma clinical trials in high-incidence, high-mortality countries to ensure that patients in the areas most affected by this disease have equitable access to interventional therapies. However, ClinicalTrials.gov is a USA-based registry and international trials are not always listed, thus the dataset may underrepresent studies conducted outside the USA. Nevertheless, the registry remains one of the most widely used global platforms for trial registration, and our findings reflect important trends in international trial distribution. Moreover, when national incidence and mortality rates are disproportionately high, as in Australia and New Zealand, the ethical responsibility to ensure transparency and global visibility of clinical research becomes even greater. While other countries are not mandated to list studies on ClinicalTrials.gov, doing so could facilitate scientific cross-border collaboration, ensure that research aligns with disease burden, and help reduce global inequities in access to investigational therapies. Expanding trial availability and improving global registration practices are critical steps toward promoting equity in care.
