Introduction
Alzheimer’s disease is a progressive neurodegenerative condition. A condition where the nerve cells are destroyed is called a neurodegenerative disorder. The condition worsens as the person ages. Hence, it is called progressive. Alzheimer’s disease is considered the main cause of dementia (memory loss) in about sixty to seventy percent of people. Although the disorder was discovered about a hundred years ago, the degradation of cognitive functioning has been frustrating.
What Is Alzheimers Disease?
Alzheimer’s disease has been found to affect more than 55 million people globally. The neurodegenerative disorder is progressive and is considered to be the main cause of dementia or memory loss in sixty percent of people. The condition is thought to have many causes behind it. One of the hypotheses in the etiology of Alzheimer’s disease is the accumulation of proteins called beta-amyloid and tau proteins. Extracellular deposits of beta amyloids called plaques and hyperphosphorylated (a process where numerous phosphoryl groups get attached) tau proteins (called neurofibrillary tangles) in the neuron are the main pathophysiology of the disease.
How Do Beta-amyloids Cause Alzheimers Disease?
Research shows that the accumulation of proteins called tau and beta amyloids is one of the causes of Alzheimer’s disease. This causes the early death of the nerve cells in the brain. These nerve cells play an important role in cognitive functions like thinking, learning, remembering, and organizing. The accumulation of beta-amyloid proteins forms abnormal masses on the nerve cells called plaques. On the other hand, the accumulation of tau proteins causes the formation of twisted fibers, which can be easily entangled. All these hinder proper communication between the nerve cells. This causes a gradual loss of cognitive functions.
The accumulation of these proteins causes the nerve cells in the brain to die earlier. The death of these cells starts in one part of the brain and gradually spreads to the other parts. This usually starts in the hippocampus of the brain. This area is responsible for memory and other cognitive functions. Research is still ongoing on how plaque accumulation occurs and how to prevent it.
What Are Anti-amyloids?
The drugs that help to reduce the accumulation of beta amyloids in the brain are called anti-amyloids. This is used on the belief that removing these amyloid proteins can help the nerve cells to function better for a longer period of time. It is a kind of immunotherapy that uses monoclonal antibodies. Immunotherapy is a type of treatment that works on bioactivation. The therapy activates or suppresses the immune system so that the symptoms become less prominent. Monoclonal antibodies are proteins made in laboratories and have the capability to bind to only one type of protein. It attaches itself to the target cells and destroys them. The first monoclonal antibody that got approved was used in the treatment of Alzheimer’s disease.
How Are Anti-amyloid Therapies Done?
The monoclonal antibody Aducanumab got its USFDA (United States Food and Drug Administration) approval in June of 2021. Another monoclonal antibody, Lecanemab-imb, received its approval in January 2023.
These drugs are inserted into the veins through needles. This process can take up to an hour. Aducanumab is advised to be taken monthly, while Lecanemab-imb is advisable every two weeks. The drugs are started on a lower dose and gradually increased to reach the level advised by the healthcare professional. Amyloid-related imaging abnormalities (ARIA) are considered a potential side effect of this therapy. It is a term introduced to describe the MRI findings in patients undergoing investigational anti-amyloid beta immunotherapies for Alzheimer’s disease. There can be areas of swelling and bleeding spots in the brain, which usually resolve on their own. Hence, regular monitoring of the brain would be required. Headache, dizziness, nausea, confusion, and vision problems can be seen as part of the side effects of the treatment. Allergic reactions, falls, and diarrhea can also be seen in some patients.
As of date, there are no contraindications (cases where the therapy can not be administered) for the therapy. No potential drug interactions (interaction between two drugs or between the drug and some other substance like food, supplements, or drinks) have also been registered. However, research has shown that the bleeding in the brain will be more if the patient is on blood thinners.
How Effective Are Anti-amyloid Therapies?
The quick approval of Aducanumab was controversial. The FDA’s advisory committee voted against it. The trials done by the drug company showed that it was effective in removing the protein plaques. However, there were no significant changes in the people with the condition. It neither improved their symptoms nor changed their outcomes.
While some studies show cases where the symptoms have been improved, others show cases where the symptoms have become worse. Hence, the results are still controversial and under research. The result of the other anti-amyloid drugs is also controversial. However, they can play a role in lowering the progression of the disease. It might be possible that the drugs might be effective when taken before too much damage is done to the brain.
What Are the Recent Advancements in Anti-amyloid Therapies?
Studies are ongoing to see how effective Aducanumab is in treating the condition. Other drugs under research include Donanemab, Gantenerumab, Lecanemab, and Solanezumab. They are also doing research on drugs that can change the course of the condition. Studies are ongoing on how to stop the production of amyloid proteins. However, these are stopped due to the harmful side effects caused. If the development of drugs in controlling Alzheimer’s disease, then the next research will be developing a vaccine for controlling the condition. There are still vaccines that are under research that are in their early stages.
Conclusion
Alzheimer’s disease is a progressive condition that affects one's cognitive functioning. It starts with mild memory loss but can progress in such a way that the patient might find it hard even to carry forward a conversation. The condition was discovered over a hundred years ago. However, the approaches to treat and manage the condition were challenging, as less was known of its etiology. Research is still ongoing on the various trials that can stop or prevent Alzheimer’s disease. A number of drugs are still under research, while other potential drugs are yet to be researched.
