A related editorial highlights the large and growing public health problem of Alzheimer’s disease and that current approved medicines for this provide little benefit. Several therapeutic strategies have been investigated in recent years, and the negative results from this study unfortunately add another treatment to the list of failures. The lack of progress in the treatment and prevention of Alzheimer disease is frustrating for patients, families, physicians, researchers, industry, funders, and policy makers. Understanding the causes for these failures is essential for informing future trials. The causes are complex and likely differ for different therapeutic strategies. However, despite the complexity of the disease, the field is generating new knowledge at an unprecedented pace. It is just a matter of time before that knowledge is translated into effective strategies for the treatment and prevention of Alzheimer disease dementia.