Contact Name

Laura Sobieck

Contact Phone

5738826376

Contact Email

sobieckl@umsystem.edu

Speaker(s) Information

Dr. Haitao Pan

Assistant Professor, Biostatistics,

St. Jude Children’s Research Hospital

Additional Event Information

Title: An Optimal Two-period Multiarm Platform Design With New Experimental Arms Added During the Trial

 

ABSTRACT: Platform trials are multiarm clinical studies that allow the addition of new experimental arms after the activation of the trial. Statistical issues, with respect to ”adding new arms”, however, have not been thoroughly discussed. This work was motivated by a ”two-period” pediatric osteosarcoma study, which will start with two experimental arms and one control arm and later add two more pre-planned experimental arms. The one common control arm will be shared among experimental arms across the trial. In this presentation, we introduce a principled approach, including, how to modify the critical boundaries to control the family-wise error rate when new arms are added, how to re-estimate the sample size and provide the optimal control-to-experimental arms allocation ratio, in terms of minimizing the total sample size to achieve a desirable power. The influence of the timing when new arms are added to the design’s operating characteristics is also examined, which provides a practical guide for deciding the timing of adding new arms. Other various numerical evaluations have also been conducted. Method of controlling the PWER has also been proposed. We have developed a R package, PlatformDesign, for practitioners to easily use this platform trial approach. A detailed step-by-step tutorial is provided in vignette.