Global trends and gaps in pharmacogenetic clinical trials: A cross-sectional analysis of ClinicalTrials.gov registrations

Pharmacogenetics has emerged role in precision medicine, yet clinical translation remains limited. Understanding the scope and focus of clinical trials is crucial to inform future implementation efforts. This study aims to evaluate the characteristics, trends, and thematic gaps of pharmacogenetic clinical trials registered on ClinicalTrials.gov. A cross-sectional descriptive analysis was conducted on interventional pharmacogenetic trials registered through 2025. Trials were identified using targeted keyword searches, and data were extracted on study phase, condition, intervention, population, and recruitment status. Frequencies and percentages were computed to describe trends and distributions. A total of 1743 pharmacogenetic and pharmacogenomic clinical trials were included. Oncology accounted for the largest share (30.1%), followed by pharmacogenetics/general (19.4%) and infectious diseases (10.3%). Phase 1 studies were the most common (45.0%), followed by Phase 2 (26.2%) and Phase 4 (20.7%). The majority of trials were reported as completed (68.9%), while smaller proportions were classified as recruiting (5.8%) or terminated (6.6%). Trial registrations peaked between 2008 and 2015 and declined thereafter. Oncology drugs, particularly irinotecan, were the most frequently studied agents, followed by antimicrobials and cardiovascular drugs. Pharmacogenetic research has expanded significantly since the early 2000s, but imbalances remain across disease areas. These Gaps highlight the need for more inclusive and diverse study designs. Addressing educational, infrastructural, and regulatory barriers is critical to advance clinical adoption.