Online Program Home
My Program

Abstract Details

Activity Number: 355 - Contributed Poster Presentations: Biopharmaceutical Section
Type: Contributed
Date/Time: Tuesday, July 30, 2019 : 10:30 AM to 12:20 PM
Sponsor: Biopharmaceutical Section
Abstract #304273
Title: Cancer Immunotherapy Trial Design with Delayed Treatment Effect
Author(s): Jing Wei*
Companies: no
Keywords: Cancer clinical trial; delayed treatment effect; piece-wise weighted log-rank test; sample size

A challenge arising in cancer immunotherapy trial design is the presence of a delayed treatment effect wherein the proportional hazard assumption is no longer holds true. As a result, a traditional survival trial design based on the standard log-rank test which ignores the delayed treatment effect will lead to substantial loss of statistical power.

Recently, Xu et al. proposed using a piece-wise weighted log-rank test to incorporate the delayed treatment effect into consideration of the trial design. However, because their sample size formula was derived under a sequence of local alternative hypotheses it results in an underestimated sample size when the hazard ratio is small for a balanced trial design and inaccurate sample size estimation for an unbalanced design. In this article, we derived a new sample size formula under a fixed alternative hypothesis. Simulation results show that the new formula provides accurate sample size estimation for both balanced and unbalanced designs.

Authors who are presenting talks have a * after their name.

Back to the full JSM 2019 program