No abstract

This paper discusses multiplicity issues arising in confirmatory clinical trials with hierarchically ordered multiple objectives. In order to protect the overall type I error rate, multiple objectives are analyzed using multiple testing procedures. When the objectives are ordered and grouped in multiple families (e.g. families of primary and secondary endpoints), gatekeeping procedures are employed to account for this hierarchical structure. We discuss considerations arising in the process of building gatekeeping procedures, including proper use of relevant trial-specific information and criteria for selecting gatekeeping procedures. The methods and principles discussed in this paper are illustrated using a clinical trial in patients with type II diabetes mellitus.

There has been constant development of novel statistical methods in the design of early-phase clinical trials since the introduction of model-based designs, yet the traditional or modified 3+3 algorithmic design remains the most widely used approach in dose-finding studies. Research has shown the limitations of this traditional design compared to more innovative approaches yet the use of these model-based designs remains infrequent. This can be attributed to several causes including a poor understanding from clinicians and reviewers into how the designs work and how best to evaluate the appropriateness of a proposed design. These barriers are likely to be enhanced in the coming years as the recent paradigm of drug development involves a shift to more complex dose-finding problems. This article reviews relevant information that should be included in clinical trial protocols to aid in the acceptance and approval of novel methods. We provide practical guidance for implementing these efficient designs with the aim of augmenting a broader transition from algorithmic to adaptive model-guided designs. In addition we highlight issues to consider in the actual implementation of a trial once approval is obtained.