Phase III Trials in India: A Comprehensive Analysis of the Clinical Trials Registry-India

Phase III clinical trials are essential for establishing the safety and efficacy of therapeutic interventions prior to regulatory approval. India has emerged as an important clinical research hub; however, long-term trends in phase III trials registered in the Clinical Trials Registry-India (CTRI) remain inadequately explored.

A comprehensive analysis of phase III clinical trials registered in CTRI between 2007 and June 2025 was conducted. Trials were categorized into two periods, namely, 2007-2014 and 2015-2025, representing pre- and post-regulatory reform eras. Data regarding randomization, blinding, comparator type, intervention model, sponsorship, study site, intervention agents, geographic scope, and recruitment status were extracted and analyzed using descriptive statistics and chi-squared/Fisher's exact tests.

A total of 1385 phase III clinical trials were analyzed. Randomized controlled trials significantly increased from 360 (88.7%) in 2007-2014 to 928 (94.8%) in 2015-2025 (p<0.001), while non-randomized studies declined. Active-controlled trials increased significantly (234 (57.6%) vs. 608 (62.1%); p=0.025), and parallel-group designs became more common (365 (89.9%) vs. 922 (94.2%); p=0.005). Industry-sponsored trials decreased from 374 (92.1%) to 799 (81.6%), accompanied by increased participation from educational and research institutions (p<0.001). Drug trials remained predominant, although vaccine and biologic/device-based studies increased significantly in the latter period. Recruitment status analysis demonstrated declining completed trials and increasing ongoing or "not yet recruiting" studies, likely reflecting stricter registration practices and pandemic-related disruptions.

Phase III clinical trials registered in CTRI demonstrated substantial improvements in methodological rigor, comparator selection, intervention design, sponsorship diversity, and reporting characteristics during 2015-2025 compared with 2007-2014. These favorable trends are temporally associated with the major Indian and international regulatory reforms, including the New Drugs and Clinical Trials (NDCT) Rules 2019, International Council for Harmonisation's Guideline for Good Clinical Practice (ICH-GCP) updates, and strengthened ethical oversight. Nevertheless, persistent challenges related to trial completion and reporting transparency warrant continued regulatory strengthening.