Introduction Regulatory views of substantial evidence

A confirmatory trial is an adequately controlled trial in which the hypotheses are stated in 

The description of a confirmatory study in ICH Guidance E9 (1998) also illustrates the importance of the study design employed. The study should be designed with several important characteristics  

Chapter 10 Confirmatory clinical trials Analysis of categorical efficacy data 

The clinical relevance, or clinical significance, of a treatment effect is an extremely important consideration. The size of a treatment effect that is deemed clinically relevant is best defined by medical, clinical, and regulatory specialists. 

Precise description of the study design and adherence to the study procedures detailed in the study protocol are particularly important for confirmatory studies. Quoting again from ICH Guidance E9 (1998, p 4)  

---