Trends in clinical research in Saudi Arabia: A registry-based descriptive analysis of ClinicalTrials.gov to 2025

Clinical research activity in Saudi Arabia has expanded, but systematic characterization of trials registered on ClinicalTrials.gov remains limited. A clearer understanding of portfolio composition, geographic distribution, and transparency indicators may support research planning and capacity development. To describe the characteristics and time trends of clinical studies registered on ClinicalTrials.gov with at least one Saudi site through 2025, focusing on sponsor type, study phase, geographic distribution, and results posting. A descriptive registry-based analysis was conducted of 1502 studies registered through August 2025. Studies were classified by sponsor, design, phase, country scope, enrollment, and therapeutic area. Geographic distribution was summarized at the city level. Registry-based transparency was assessed as the proportion of studies with posted results overall and among completed studies. Most studies were interventional (75.5%), with greater activity in later phases such as Phase 3 and limited early-phase research. Nonindustry sponsors led 73.0% of registrations. Planned enrollment was modest, with half of the trials targeting 100 or fewer participants. Trial activity was concentrated in Riyadh, with smaller hubs in Jeddah and Dammam. Transparency was low, with only 12.1% of studies posting results. Among completed trials, industry sponsors reported results more frequently than nonindustry sponsors. Neurology, oncology, and endocrine disorders were the most represented areas, while cardiovascular and respiratory research were comparatively underrepresented. Saudi Arabia's clinical research portfolio shows growth in late-phase activity and increasing participation in multinational studies. The observed geographic concentration and low rates of results posting, particularly among nonindustry sponsors, suggest opportunities to strengthen early-phase infrastructure, broaden participation beyond major hubs, and support timely and consistent results disclosure through institutional processes.