The WIZARD trial as a case study of flexible clinical trial design

The design of a randomized, controlled, confirmatory efficacy clinical trial is influenced by multiple competing factors, including ethical, scientific, economic and regulatory interest. Design elements, including choice of end points, study duration, and interim monitoring plans, need to be adapted to specific circumstances. They Weekly Intervention With Zithromax for Atherosclerosis and Its Related Disorders WIZARD) study design was initially intended to meet the sponsor's scientific goals while being subject to practical constraints. In response to changing circumstances, modifications to the study design were required. The WIZARD trial demonstrates the substantial flexibility in the design and conduct of group sequential randomized trials not only during the design stage but also after the trial is under way, effectively satisfying evolving and competing demands while preserving the statistical and scientific validity of the study.