In the U.S., nearly seven million people over the age of 65 years suffer from Alzheimer’s dementia. Despite being a “fast-track” condition for the FDA and drug development, current treatments are lacking–there aren’t really any great medications that slow Alzheimer’s dementia, and the illness tends to progress rapidly resulting in a marked decline in function and caregiver burdens. But there have been a few newly approved Alzheimer’s drugs recently that are offering a glimmer of hope. Though these are far from a cure, these new medications do suggest better therapies may soon be available.
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These newly approved Alzheimer’s drugs work by essentially targeting structural abnormalities in the brain. In Alzheimer’s dementia, different proteins trigger what’s called senile plaques and nerve tangles. Key proteins include amyloid and tau protein. Recent research has explored whether targeting these proteins and eliminating them might help the condition. It’s believed this approach could yield medications that slow Alzheimer’s dementia and maybe even prevent it. Of course, this is just one piece of a very complicated puzzle. But it’s one in which drug companies are investing heavily in hopes of a breakthrough. And two newly approved Alzheimer’s drugs certainly fit into this category.
The Anti-Amyloid Alzheimer’s Drugs
For many conditions, monoclonal antibody therapies are being developed. These types of medications provide a targeted attack using immune antibodies to alter or eradicate a protein linked to a disease. This is precisely what some of the newly approved Alzheimer’s drugs do with monoclonal antibodies against amyloid protein. In theory, eliminating amyloid would prevent senile plaques associated with the dementia. This may be particularly true if given early in the disease before plaques have a chance to disrupt brain function. Even if these strategies proved to be partially effective, they would be welcomed. This is because medications that slow Alzheimer’s dementia have yet to be found to date.
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In the past year, two anti-amyloid drugs have been developed to treat Alzheimer’s dementia. The first of these newly approved Alzheimer’s drugs is Leqembi manufactured by Eisai and Biogen. The other, which was just FDA approved as one of the medications that slow Alzheimer’s dementia, is Kisunla. It is produced by Eli Lilly and similarly involves monoclonal antibody mechanisms against amyloid proteins. It’s worth noting that both of these medications are given via intravenous infusions periodically. For Leqembi, these infusions are required every two weeks. For Kisunla, monthly treatments are needed based on drug trials. And neither of these monoclonal antibody therapies are cheap. Leqembi goes for about $26,000 a year while Kisunla has been listed at $32,000 annually. While this is pricey, the need for medications that slow Alzheimer’s dementia is profound. This is why CMS has proposed covering the drugs for Medicare and Medicaid in the near future.
The Good and Bad of These Newly Approved Alzheimer’s Drugs
Notably, Leqembi was the first of these newly approved Alzheimer’s drugs that targeted amyloid. While it has received some positive attention, there are some caveats to its use in this condition. In addition to its more frequent administration, it must be given indefinitely according to the medications research trials. It also has noted side effects that include risks of brain swelling and brain bleeding. These issues as well as its costs are concerns. Kisunla, the other one of the anti-amyloid medications that slow Alzheimer’s dementia. Offers a slightly better profile. It only needs to be administered monthly. Plus, once all existing amyloid is eliminated in the brain, the medication can be stopped. These aspects make it a more favorable alternative.
The recent trial involving Kisunla enrolled over 1,700 patients with either mild dementia or mild cognitive impairment. Each had to undergo PET scans to determine amyloid plaque burden. They also had to undergo a series of MRI scans to assess risks for treatment. Like Leqembi, Kisunla also can cause brain swelling and bleeding. Thus, MRIs were used to assess predisposed risks related to these complications. Over the 18 months of the drug trial, the treatment group declined nearly 30% slower in cognitive function. In addition, half were stable in function at a year compared to only 29% of the placebo group. At the same time, nearly half of the patients were able to stop the drug within a year. And while a quarter had some brain swelling or bleeding, only 2% of the patients had serious problems with this. Clearly, these newly approved Alzheimer’s drugs aren’t perfect. But they’re the only medications that slow Alzheimer’s dementia from progressing to date.
Looking Ahead to Better Treatments
Based on the recent trials of these newly approved Alzheimer’s drugs, significant room for improvement is evident. While costs and side effects of these medications is desirable, the more important thing is efficacy. Medications that slow Alzheimer’s dementia progression is a good first step, but complete prevention and cures are preferable. This is challenging given the fact that structural brain impairments and loss of neurons aren’t easily reversed. Therefore, expect future treatments to focus on early detection, prevention, and protection. Both of these new anti-amyloid drugs reflect this direction of investigation. And though they are far from perfect, they highlight the focus of the pharmaceutical industry at present.
Notably, there remains many questions even about these newly approved Alzheimer’s drugs. For example, since both target amyloid, it might be presumed that patients with larger amyloid burdens would respond the best. However, this wasn’t the case in the latest trials. In addition, dementia patients with higher levels of tau proteins had less of an effect from the medication. Tau protein, which is associated nerve tangles in the brain, might be a more important target as a result. In fact, ongoing research into anti-tau protein drugs are being pursued. This might be another treatment area that reveals even better medications that slow Alzheimer’s dementia worsening. Given this, much works still needs to be done. But every new discovery is a step closer to better Alzheimer’s disease management.
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