^*The number of clinical trials conducted in 2013 and 2023 for each cancer type was extracted from ClinicalTrials.gov and WHO ICTRP databases using relevant keywords (e.g., “brain cancer,” “bone cancer,” “pediatric cancer,” “leukemia”) and filtered by trial phase and start date. The data were validated using peer-reviewed publications on the trends in rare cancer research [41]. The classification of trial types was informed by recent reviews of oncology trials [42] and included adaptive trials, biomarker-driven designs, RNA-based therapies, and immunotherapies. Median sample sizes were calculated based on published analyses of rare cancer trials and aggregated from trial datasets. Success rates for Phase III trials were determined from historical data published in oncology-specific meta-analyses [43], which reported an average success rate of 3.4% for all oncology trials, with higher rates observed for rare cancers due to biomarker-driven approaches. CAR-T: chimeric antigen receptor T-cell therapy; ICTRP: International Clinical Trials Registry Platform; WHO: World Health Organization.