Reanalysis of the A4 Study to Formally Evaluate Amyloid Removal as a Surrogate for Cognitive Decline

Using epidemiologic and econometric methods to analyze individual-level data from trials of amyloid-targeting drugs will improve our understanding of amyloid as a surrogate outcome for cognition. In this instance, results are imprecise because solanezumab did not effectively remove amyloid. However, reproducing these analyses using individual-level data from effective anti-amyloid trials has the potential to shape treatment strategies and inform use of surrogate outcomes in future approval processes.