The Integrated Alzheimer’s Disease Rating Scale (iADRS) Findings from the EXPEDITION3 Trial

The Integrated Alzheimer’s Disease (AD) Rating Scale (iADRS) is a composite tool that combines scores from the AD Assessment Scale-Cognitive subscale (ADAS-Cog) and the AD Cooperative Study - instrumental Activities of Daily Living (ADCS-iADL). It demonstrates acceptable psychometric properties, and is effective in capturing both disease progression and separation of placebo and active drug effect. We assessed the performance of iADRS in the solanezumab EXPEDITION3 study, an 80-week, placebo-controlled study of individuals with mild AD dementia. A statistically significant difference between placebo and active drug was observed for iADRS score change from baseline at Week 28 (p=0.028) through Week 80 (p=0.015). Across the Phase 3 solanezumab trials, iADRS was the only tool that consistently differentiated between solanezumab and placebo groups. These findings suggest that the iADRS is a useful integrated measurement tool for treatment trials of individuals with mild AD dementia.