2021 Colloquia

A Randomized Phase II Design which Brings in Information on the Control Arm from Past Studies to Reduce the Sample Size

Mithat Gonen, Ph.D.
Memorial Sloan-Kettering Cancer Center

Phase II cancer trials are traditionally designed as single-arm, with the null hypothesis chosen ahead of time, presumably from the literature. This approach is often criticized for its lack of rigorous control but the practice continues, partly because a concurrent control arm will substantially increase the sample size. An unbalanced randomization with more patients randomized to the treatment arm is advocated as a way to keep the sample size in check, but when the resulting trial is analyzed using a traditional comparison, this planned imbalance actually reduces power. We propose a hybrid-approach where an imbalanced randomization scheme is implemented but the data for the control arm are augmented with historical information using a Bayesian approach. We will review the use of power priors and related methods to evaluate the gains from this procedure. While similar literature focuses on power improvements, we will also show implications for Type I error control.

Thursday, October 21, 2021
3:30 p.m. - 5:00 p.m.
Helen Wood Hall - Room 1W-509

What's in a Model? The Role of Bayesian Inference in the Age of Data Science

Joseph Hogan, ScD
Brown University School of Public Health

2021 Andrei Yakovlev Colloquium

Thursday, September 23, 2021