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Clinical trial for first Alzheimer's drug with effect on cognitive decline looks for South Texas recruits

Doctors may eventually be able to diagnose "preclinical" Alzheimer's in patients who have abnormal brain scans but who aren't yet showing behavioral symptoms of the disease.
iStockphoto
Doctors may eventually be able to diagnose "preclinical" Alzheimer's in patients who have abnormal brain scans but who aren't yet showing behavioral symptoms of the disease.

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UT Health San Antonio’s Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases is participating in a national clinical trial to assess whether a drug, lecanemab, can prevent or slow the onset of Alzheimer’s in patients who are not yet symptomatic.

Lecanemab, an antibody, was recently found to slow cognitive decline by 27% for those in the early stages of Alzheimer’s, according to a study published in the New England Journal of Medicine (NEJM).

Now, in partnership with UTRGV, the Biggs Institute is one of a few dozen Alzheimer’s Disease research centers in the U.S. working on a clinical trial to see whether lecanemab can slow cognitive decline for those individuals who have the markers for Alzheimer’s but are not yet experiencing symptoms. That’s because a protein associated with Alzheimer’s, amyloid, can be detected 10 or 20 years before the onset of any cognitive decline.

Together, they are seeking volunteers who meet those criteria between the ages of 55 and 80 to join the clinical trial.

Dr. Arash Salardini is the Klesse Foundation Distinguished Chair in Alzheimer’s and Neurodegenerative Diseases and the principal investigator for the clinical trial at the Biggs Institute. He said they’re testing the drug on patients who don’t experience Alzheimer’s symptoms.

“Now what we want to do, and this is also a national trial, is to apply this before people have symptoms, so while their immune system is working at its best,” he said. “The idea is that if you can stop this amyloid and remove this amyloid before people have any symptoms, that you can preserve much of their cognition.”

Scientists have long sought a way to detect Alzheimer's before symptoms appear.
iStockphoto
Scientists have long sought a way to detect Alzheimer's before symptoms appear.

The hope, Salardini said, is that because the immune system is still at full strength in these patients, cognitive decline can be slowed even more and produce even better outcomes.

While lecanemab produced positive results for many of the clinical trial participants in the NEJM study, it’s important to note its shortcomings and potential harms.

The drug is not intended to stop or reverse cognitive decline entirely, just slow it. Lecanemab also carries with it some potentially harmful side effects — brain inflammation and brain bleeds — as a result of Amyloid Related Imaging Abnormality (ARIA). There were also two patient deaths during the initial study of lecanemab, or 0.2% of the 898 patients who were on the drug.

Salardini acknowledged that while there are certainly advantages of participating in the clinical trial — getting access to a clinical drug for Alzheimer’s and advancing scientific understanding of the disease — potential volunteers should understand there is some level of risk they would be taking.

“We have mechanisms to try to mitigate that [from] happening, and surveillance that we do to minimize that, but we can’t minimize [risk] down to zero,” Salardini said.

This clinical trial will be a double-blind study of around 1,400 patients. A control group of patients receive a placebo, and an experimental group of patients receive lecanemab. Neither the patients nor the researchers will know who is receiving what. These double-blind studies work to prevent bias from affecting the outcome, a rigorous method of research.

UTRGV
Barbara Brannon
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The University of Texas Rio Grande Valley is participating in the clinical trial with UT Health San Antonio's Glenn Biggs Institute.

Salardini said the Biggs Institute is just a small piece of the study, and is seeking 20-40 volunteers from the South Texas area. He said one big advantage of being in South Texas is that they hope they will be able to bring in more Latino participants.

“Diversity is not just a political sort of thing that we’re trying to be inclusive, it actually makes the science applicable to all the populations that were recruited,” he said. “We are … in the fortunate situation where we have a very vital, very dynamic, quite educated Mexican-American population here in San Antonio, and I think having them in the trial would just make the results much more meaningful.”

To be clear, all humans have near-identical DNA, there is far more genetic variation within races and ethnicities than between them, and there is no genetic basis for race. But diverse populations in studies like these are important because minor genetic differences based on geographic origin can affect how diseases and treatments impact certain populations.

Salardini made clear that lecanemab is likely not a miracle drug to cure Alzheimer’s, and there are still many questions among researchers about the ultimate efficacy of a drug like lecanemab — an editorial in the scientific journal The Lancet cautioned against overstating the impact of the drug for numerous reasons, such as a potentially prohibitively-high cost, harmful side effects, difficulty administering the drug in poorer countries, and whether it’s actually slowing cognitive decline enough to be clinically meaningful.

But in the same editorial, its authors said lecanemab could pave the way forward for new drugs. Salardini agreed.

“Another one of these intractable problems at one stage was HIV,” he said. “But once they found the first drug — which was AZT — they had a good idea of what the mechanism was, so they could bring about combination therapies which now makes HIV not a fatal acute disease, but rather a chronic, somewhat manageable condition. And that’s the sort of thing we want for Alzheimer’s.”

CORRECTION: A previous version of this story misspelled the names of the Klesse Foundation and the Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases.

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Josh Peck is the Technology & Entrepreneurship Reporter for Texas Public Radio.