R&D imbalance in rare‑disease medicines in China: A cross‑sectional analysis of clinical trial registrations and coverage by the national rare‑disease catalogue

Abstract Objective From the perspective of R&D resource equity, this study systematically describes the registration landscape of clinical trials for rare‑disease drugs in China, evaluates the clinical development coverage of diseases included in the two batches of China’s Rare Disease Catalogue, and identifies major R&D gaps and structural problems. Methods We retrieved data from the National Medical Drug Clinical Trial Registration and Information Disclosure Platform up to 15 August 2026. Search terms comprised official standard names and common aliases of the 207 disorders listed in the two‑batch Rare Disease Catalogue. Two independent trained investigators performed screening and verification. Drug‑based interventional clinical trials were enrolled according to pre‑defined criteria. Information including trial registration number, trial phase, drug category, sponsor, indication, and first public release date was extracted. Descriptive statistics, chi‑square test and Fisher’s exact test were applied for between‑group comparisons. Results A total of 1 256 eligible trials were included, covering 107 (51.7%) catalogue‑listed diseases. The annual number of trials rose from 6 in 2013 to 192 in 2025, with marked acceleration after 2018. Chemical drugs accounted for 54.5% and biological products for 44.8%; domestic enterprises sponsored 68.2% of all trials. The top 10 diseases by trial volume cumulatively contributed to 53.4% of total trials, among which haemophilia, idiopathic pulmonary fibrosis and melanoma ranked highest. Numerically, diseases in the second catalogue batch showed higher trial coverage (58.1%) than those in the first batch (47.1%), though the difference was not statistically significant (χ² = 2.45, df = 1, P = 0.12). Domestic sponsors conducted significantly more early‑phase trials than foreign sponsors, with a statistically significant difference in phase distribution between the two groups (χ² = 241.25, df = 1, P < 0.001). One‑hundred catalogue‑listed diseases had no registered clinical trials at all; inherited metabolic and endocrine diseases together made up 42% of these uncovered conditions. Conclusions The volume of registered clinical trials for rare‑disease drugs in China has increased substantially. Nevertheless, R&D resources are heavily concentrated on a small number of diseases, leaving numerous rare diseases with no R&D activity, which indicates prominent inter‑disease R&D imbalance. Policy incentives should be further tilted toward unmet medical needs in under‑explored areas. Our findings may provide references for rare‑disease R&D governance in other low‑ and middle‑income countries worldwide.