ICH E20 Draft Guideline Sets Global Standards for Adaptive Clinical Trials
The ICH E20 guideline, released as a Step-2 draft in June 2025, establishes globally harmonized principles for adaptive clinical trials. This draft consolidates previous regional guidance from the FDA and EMA, providing a unified regulatory framework for confirmatory trials employing adaptive designs. The guideline emphasizes Type I error control, estimation of treatment effects, and trial integrity. It introduces a common regulatory lexicon and expands recognition of Bayesian and enrichment-based designs. The scope includes Phase III or other confirmatory trials, excluding early-phase exploratory studies unless part of a seamless confirmatory program. The guideline aims to enhance transparency, documentation standards, and methodological expectations for sponsors planning adaptive trials. 
