By Jackie Kimmell, Senior Analyst
Thousands of scientists met at the Alzheimer's Association International Conference this week in Chicago to discuss new findings about disease—which already afflicts 5.5 million Americans, and could affect three times as many by 2050.
If you've been reading about all seven days of presentations about clinical trials, lifestyle studies, clinical practice recommendations, and more, you're probably feeling overwhelmed. To help, we've read through the presentations and explained the three most important things you should know.
1. A new Alzheimer's drug created huge media buzz—but there's reason for caution
The results of a trial exploring a drug called BAN2401 generated huge buzz when they were released on Wednesday. While many became excited about the drug as a potential treatment for Alzheimer's, the buzz might say more about the disheartening state of Alzheimer's drug trials as a whole than about the trial's actual results.
The phase II trial did not meet its primary endpoint—that is, the measure of success that the developers had set at the onset of the trial. An early analysis announced in December 2017 showed only a 64% chance that the drug reduced the rate of cognitive decline by 25% or more, compared to a placebo. Researchers had hoped for at least 80% probability.
However, after following patients for longer, they became more optimistic. Additional analyses indicated that the drug might slow the pace of cognitive decline and reverse the buildup of amyloid plaques—which a fierce subset of scientists believe are the main culprit in Alzheimer's, as they block communication between the neurons and can eventually kill them.
New analyses showed that patients receiving the highest of the possible five does of the drug had 30% slower cognitive decline and that all brain dosing groups appeared to have reduced levels (around 70% on average) of amyloid plaques in brain scans.
However, only a small subset—161 people who received the highest dose—actually saw the benefits of the drug. In addition, the trial could have been subject to a serious potential confounding variable. To ensure patient safety, investigators monitored patients for swelling of the brain, particularly patients with a gene called APOE4 (which has been found to speed up cognitive decline). In 2014, an unspecified regulatory agency outside of the US requested that the trial stop assigning those with this gene to the highest dose group of the trial. Researchers complied.
This change could mean that that 161-person high-dose group could have shown slower mental decline not because the drug was working, but because it contained fewer people with a genetic predisposition that caused them to decline more quickly.
This has hampered some enthusiasm among the Alzheimer's community, but many are still excitedly awaiting the next trial of the drug. While many other promising phase II trials have failed in future studies, at least this drug looks promising so far.
2. Reducing blood pressure can help prevent dementia—at least in some patients
Researchers also presented evidence, in an extension of the landmark SPRINT study, that participants who lowered their blood pressure also reduced their risk of developing early dementia. The study assigned more than 9,300 elderly people who either had heart problems or were at a high risk of developing heart disease to lower their systolic blood pressure—that is, the first number in a blood pressure reading—to either less than 120mmHg or 140mmHg. (Current guidelines recommend a level under 130mmHg.) They found that those who lowered their blood pressure to under 120mmHg, compared to those who lowered it only to 140mmHg, decreased their risk of both mild cognitive impairment (MCI) and probable dementia by 15% more.
Since the study followed participants for only five years, researchers weren't able to evaluate whether participants actually developed full dementia (which takes longer to develop), just probable dementia or MCI.
The results are notable because this is the first time that scientists have found individuals can lower their dementia risk in a controlled, randomized trial. The finding shows the pernicious impact of high blood pressure on our brains. We know that that high blood pressure can damage the walls of the delicate arteries that deliver blood to the brain. Over time, high pressure can weaken these walls and cause inflammation or small strokes—both of which are likely to lead to dementia.
However, more research must be done on the topic to determine whether the findings hold true for the general population. Because all participants had a history of heart problems, the results can't yet be generalized to people who have high blood pressure but no existing heart problems.
3. The first multi-specialty clinical guidelines for recognizing Alzheimer's are here
A working group at the Conference presented a list of 20 clinical recommendations to help physicians and nurse practitioners recognize the symptoms of Alzheimer's Disease and Related Dementias (ADRD). These were the first national guidelines aimed at providers in multiple specialties.
Notable in these rules was an increased emphasis on widening the types of symptoms—particularly behavioral symptoms—that can accompany Alzheimer's. "Too often cognitive and behavioral symptoms due to Alzheimer's disease and other dementias are unrecognized, or they are attributed to something else," James Hendrix, PhD, the Alzheimer's Association's Director of Global Science Initiatives said in a statement. "These new guidelines will provide an important new tool for medical professionals to more accurately diagnose Alzheimer’s and other dementias."
The new guidelines will recognize a wider set of changes, such as those in mood, anxiety, sleep, and personality, as well as those in work, interpersonal, and social relationships, that can appear before the more familiar symptoms of dementia—such as memory and thinking problems. Recognizing these other symptoms earlier can help with earlier detection of the disease and allow for better treatment.
The full list of recommendations, and the detailed rationale behind each one, will be published later this year in a peer-reviewed journal (Belluck, New York Times, 7/15; Servick, Science, 7/26; Park, Time, 7/25; Gingerich, MDMag, 7/23; Brooks, Medscape, 7/23).
Read our other coverage on the conference, including why it can cost as much as $100k to enroll one participant in an Alzheimer's trial, as well as how female sex hormones seem to protect women from developing dementia.