How Can We Improve Transfer of Outcomes from Randomized Clinical Trials to Clinical Practice with Disease-Modifying Drugs in Alzheimer's Disease?

Abstract

Background: Randomized clinical trials (RCTs) for putative disease-modifying drugs in Alzheimer's disease (AD) are using cognitive outcomes, such as the Alzheimer's Disease Assessment Scale - cognitive subscale, activities of daily living scales, such as the Alzheimer's Disease Cooperative Study Activities of Daily Living, and time from mild cognitive impairment to AD dementia. Objective: It was the aim of this study to build clinically relevant outcomes for future use in clinical practice into RCT designs and help third-party payers to measure benefit. Methods: We used a literature review for analysis. Results: The Clinical Dementia Rating Scale Sum of Boxes (CDR-SB) appears to be the most reliable primary outcome for RCT at different stages of AD, with the Relevant Outcome Scale for Alzheimer's Disease (ROSA) as a suitable alternative. The importance of current AD biomarkers vis-à- vis determination of efficacy of disease-modifying drugs has yet to be established; however, it is likely that at least one amyloid-specific test will be required prior to treatment with a drug acting predominantly on β-amyloid (Aβ42). Furthermore, serial MRI may be required to monitor adverse side effects associated with such drugs. Conclusions: Global clinical scales such as CDR-SB and ROSA should be considered for use with treatments aiming at slowing disease progression.