Cytel Blog Discusses Whether Promising Zone Design is Optimal

December 14, 2021

Jennison and Turnbull developed promising zone design in 2015 to help determine initial sample sizes for early clinical trials that could be expanded if preliminary results are positive. This was developed to supplant previous study approaches like group sequential design, which uses a large sample size to identify minor effects but pares down numbers if a significant effect is found. A 2019 paper by Hsiao, Liu, and Mehta proposed a constrained model to improve upon standard promising zone design.

According to a blog article from Cytel, the authors “present a constrained promising zone design where the constrained is imposed to ensure a minimal conditional power. This constrained promising zone design is evaluated against the optimal unconstrained Jennison and Turnbull (2015) design and against a constrained version of the Jennison and Turnbull design.”