577 – Recent Advances in Mental Health Clinical Trial Design: Statistical Challenges and Opportunities
On Clinical Trials with a High Placebo Response Rate
George Y.H Chi
Janssen R&D
Yihan Li
AbbVie
Yanning Liu
Janssen R&D
David Lewin
Janssen R&D
Pilar Lim
Janssen R&D
The basic reason for the failure of many standard randomized parallel placebo-controlled clinical trials with high placebo response rate is that the observed relative treatment difference only provides an estimate of the apparent treatment effect since the true treatment effect has been diminished by the presence of a substantial proportion of placebo responders in the population. Analogous to an active control trial, the true treatment effect cannot be measured by the relative treatment difference. An appropriate assessment of the true treatment effect is critical for making a risk/benefit analysis and dosage recommendation. The primary purpose of this paper is to propose a method for adjusting the apparent treatment effect to account for the high placebo response rate within the framework of a doubly randomized delayed start design.