ICH E20 Draft Guideline Introduces Global Standards for Adaptive Clinical Trials
The ICH E20 guideline, released as a Step-2 draft in June 2025, aims to establish globally harmonized principles for adaptive clinical trials. This guideline consolidates previous regional guidance from the FDA and EMA, providing a unified regulatory framework for the planning, conduct, analysis, and interpretation of confirmatory clinical trials using adaptive designs. Key aspects include Type I error control, estimation of treatment effects, and trial integrity. The guideline targets confirmatory trials, offering detailed expectations for planning, statistical methodology, and documentation. It also recognizes modern design classes such as Bayesian and enrichment-based designs, emphasizing the need for alignment between adaptation decisions and clinical questions. 
