Will Alzheimer's Research Ever Return to Normal?

Ronald C. Petersen, MD, PhD; John C. Morris, MD


August 04, 2020

This transcript has been edited for clarity.

Ronald C. Petersen, MD, PhD: The whole situation of COVID-19 has complicated the research picture for Alzheimer's disease. In particular, in regard to clinical studies, they have been significantly impacted. We can break them down into three classes. We can talk about randomized controlled trials involving an intervention.

John C. Morris, MD: There are several compounds that appear to have the possibility of being effective in Alzheimer's disease. All of them had to be put on hold until such time as the pandemic allows individuals to resume their participation. The clinical trial impact is the most meaningful problem for Alzheimer's research. Hopefully, the trials can resume and we can determine whether these agents truly benefit people with Alzheimer's dementia.

There are at least three compounds that appear to have some potential to be effective. All of those randomized trials had to be suspended in mid-March. Just now, we're trying to see if we can begin to resume having participants come in for their evaluation. This means we've lost about 2.5-3 months of testing whether these agents will benefit people. We can't give participants the drug during the suspension because if they develop a side effect, we need to be able to evaluate that immediately. That's been suspended also.

Petersen: We've had to interrupt these studies. We may have to bring them back at a later point in time. It depends on the individual study how this is handled. You could deal with it as a missing visit if it fell during this period when the clinical studies are shut down, or you could delay it and have the visit pushed out weeks to a month. Both of these are acceptable, but they present complications for analyzing the data.

Nevertheless, it seems that the interventional studies in symptomatic people are resuming at present. The second category would be interventional studies in people who are cognitively unimpaired, the so-called prevention studies. Now these are starting to resume as well.

Here, you have individuals who are cognitively normal, receiving some type of an intervention. You face the same issues in regard to missing data versus a postponed visit. It all depends on where the study is being performed and what kind of goal is being achieved by the study as to how the decisions will be made.

Morris: Several clinical trials that had to be suspended involve prevention therapy, including, for example, a very rare group of individuals who develop Alzheimer's disease because they inherit a gene mutation that causes the illness. Those individuals are destined to develop symptomatic Alzheimer's disease, typically at an early age in the mid-forties rather than after age 65, as we notice in the far more common nongenetic forms of Alzheimer's disease.

There are two drugs being tested, and one of the drugs seemed to halt the brain pathology of Alzheimer's disease that already was building up, even though these individuals were asymptomatic. The report of this came out in February. The idea was that we would give that agent that seemed to reverse the pathology of Alzheimer's disease to these individuals to see if it could prevent the development of Alzheimer's dementia. That had to be suspended in mid-March because of the pandemic.

Petersen: Finally, the third type is an observational research study where people are not receiving an intervention but are coming in for a clinical evaluation and are being followed longitudinally. These are individuals, again, who may be symptomatic or unimpaired, and we're following them longitudinally. Again, we face the same issues. Do we just push back the visit? Do we call this missing data? It becomes complicated, but we're going to be able to work through this research complication.

Morris: I think the pandemic has taught all of us that we will not return, at least immediately, to the pre-pandemic way of doing things. People will be understandably apprehensive about coming in to a research setting where there are other people, and maybe in a hospital setting where there could be individuals who are affected by COVID-19.

I don't think recruitment is going to just simply pick up from where we left off. We'll have to think of new ways to try to recruit individuals and perhaps use the kinds of technologies that we've all become accustomed to, with videoconferencing and telephone assessments, and allow people to remain in a setting such as their home where they may feel safe, rather than coming to a medical center where they may not feel safe.

We will begin, cautiously, to resume these trials with in-person visits whenever it's safe to do so, but we will have to adapt to the effects of the pandemic and do so in a way that is safe not only for the participants but also for the research team.

Dr Petersen directs the Mayo Clinic Alzheimer's Disease Research Center in Rochester, Minnesota, as well as the Mayo Clinic Study of Aging, both of which involve the study and characterization of aging individuals over time, with an emphasis on neuroimaging and biomarkers.

Dr Morris is the Harvey A. and Dorismae Hacker Friedman Professor of Neurology and director of the Alzheimer's Disease Research Center at Washington University in St. Louis, Missouri.

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