Limitations of early phase trials

In this chapter we have discussed the importance, and the strengths, of early phase clinical trials. Before moving on to later phase clinical trials, it is also appropriate to consider their limitations. The word limitations should not be seen as a negative assessment in this context. As we will discuss in Chapter 12, later-phase preapproval clinical trials also have their limitations. Acknowledgment of the strength and the limitations of any method of inquiry is legitimate and helpful As Katz (2001, p xi) noted, to work skillfully with evidence is to acknowledge its limits.  

The advantage of very tight control in early Phase II (therapeutic exploratory) trials is that the pure efficacy of the drug can be assessed as well as possible. The drug has every chance to demonstrate its efficacy in these circumstances. 

What are some reasons that inferential statistics (that is, hypothesis testing) are not used very often in early phase studies  

What information from early phase trials may be used to inform the study designs of therapeutic exploratory and therapeutic confirmatory trials  

Name three advantages or strengths of early phase trials as they pertain to the overall development of a new drug. 

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