Statistical Approaches to Analyzing Historical Control Data from Two-Year Rat Carcinogenicity Studies

• Activity Number: 530
• Type: Contributed
• Date/Time: Wednesday, August 7, 2013 : 10:30 AM to 12:20 PM
• Sponsor: Biometrics Section
• Author(s): Lei Shu*+ and Lanju Zhang and Ronnie Yeager
• Companies: Abbvie Inc. and Abbvie and Abbvie
• Keywords: Carcinogenicity study ; Body weight ; Frailty ; Gompertz ; Historical Control Data ; Survival

Abstract

Historical control data can play a pivotal role in data interpretation from two-year carcinogenicity studies. In this talk, new statistical approaches will be applied to analyze the data from 30 historical control groups with four types of vehicles (water, methylcellulose, ad libitum diet/feed, and a non-proprietary lipid mixture) from two-year Sprague Dowley rat carcinogenicity studies. The objective of this analysis was to evaluate potential vehicle-related effects on animal survival or body weight, which could then be used for vehicle-specific sample size estimation and body weight monitoring. Cox proportional hazard model with/without frailty will be applied to analyze the survival data. Gompertz and logistic nonlinear mixed-effects models will be used to analyze the body weight growth in rats. These approaches will be compared with each other on their statistical properties. Example results will be presented to illustrate each analysis approach and the comparisons.