阿尔茨海默病 is a condition that not only challenges those who suffer from it, but also the scientists and doctors who strive to combat it. But a new treatment has emerged that offers a glimmer of hope by slowing progression of the disease.
Lecanemab is an infusion that targets amyloid, one of the two abnormal proteins that accumulate in the brains of patients with 阿尔茨海默病, 解释 S. Thomas 卡迈克尔 Jr.，医学博士，博士，委员会主席 Department of 神经学 at UCLA 健康. “Lecanemab recognizes amyloid. Once it’s infused into the bloodstream, it crosses into the brain, where it binds to this abnormal protein and causes the brain to clear it into the bloodstream and then get rid of it.”
While it decelerates progression of the disease, the drug does not reverse Alzheimer's.
The Easton Center for Alzheimer's 研究 and Care at UCLA was instrumental in the multicenter Clarity AD trial, which is now in phase 4 clinical trials after the FDA approved the efficacy and safety of lecanemab in the early stages of 阿尔茨海默病. The findings were promising: Not only did lecanemab diminish the presence of amyloid indicators, it also slowed the rate of cognitive and functional deterioration when compared with the control group receiving a placebo.
“At the clinical trial level, people essentially had a six-month delay in disease progression, compared to those who didn't receive lecanemab,” Dr. Carcmichael说. “Lecanemab remarkably clears one of the bad proteins, but there's kind of a mismatch – while there is this profound effect of it clearing up one of the bad proteins, there’s only a modest effect on cognitive function.”
This mismatch is at the heart of a broader debate within the scientific community: While amyloid clearance is achieved, the cognitive benefits are not as dramatic as researchers hoped. “This is where the controversy is,” Dr. 卡迈克尔表示. “多年来, scientists thought that amyloid was the main cause of mental decay in patients with 阿尔茨海默病. What this tells us, however, is that we can remove amyloid, and that helps, but surprisingly little.”
The hope for the future of lecanemab as a treatment for 阿尔茨海默病 is that it will pave the way for further advances and newer therapies that will lead to more significant long-term outcomes.
Rather than being a standalone therapy, Dr. 卡迈克尔 foresees lecanemab as part of a multi-pronged approach to treating Alzheimer’s disease. “This will be one of our tools to treat 阿尔茨海默病, but we'll need others,” he said. “I'm not sure what those will be. 但很明显, there's going to be several drugs that we will need” for a comprehensive treatment strategy.
While the FDA approved lecanemab, 它把另一个, similar Alzheimer’s drug, donamemab, on hold for further safety review. That decision has surprised many in the scientific community, including Dr. 卡迈克尔. Both drugs are monoclonal antibodies that target amyloid, and both carry risks of brain swelling and bleeding. “The two drugs are very similar in their systems of care and delivery, so I'm not sure why they would be so cautious about approving donanemab after approving Lecanemab,” Dr. 卡迈克尔表示. “It may be because of a third drug, which was the first one and was highly controversial, 叫aducanemab. The FDA flagged that drug, and perhaps that has made them move cautiously going forward.”
