Alzheimer’s disease is a progressive brain disorder that damages memory and thinking skills. It can eventually make it difficult to perform simple tasks. In its final stage, people with Alzheimer’s disease may be unable to talk with family members or know what is going on around them. It is the most common type of dementia and accounts for 60–80% of dementia cases in the United States.

Several prescription medications are used for Alzheimer’s disease treatment and are considered standard care. These medications are used to manage symptoms and slow the progression of the disease. Since the first approval of an Alzheimer’s medication in 1993, therapy has been based off two classes of medications, cholinesterase inhibitors and NMDA receptor antagonists. Unfortunately, there are no currently known treatments that will cure Alzheimer’s.

Lecanemab is the newest treatment that is available and was approved by the FDA in 2023. Lecanemab has been approved for the treatment of early Alzheimer’s disease. Lecanemab works by targeting and clearing amyloid-beta plaques in the brain, which are believed to contribute to the progression of Alzheimer’s disease. The key findings from the CLARITY AD study led to the approval by the FDA, here is a summary:

Study Overview

The CLARITY AD study looked at the efficacy or effectiveness and safety of lecanemab in patients with early Alzheimer’s disease. Patients included in the study had mild cognitive impairment due to Alzheimer’s or mild Alzheimer’s dementia.

Efficacy:

Lecanemab showed a significant reduction in amyloid plaques in the brain and slowed the rate of cognitive decline when compared to placebo. Cognitive decline was measured by tests which assessed the severity of dementia symptoms.

Safety:

The most common side effects reported were flu-like symptoms (chills, fever, flushing, nausea/vomiting, and headache) from infusion of the medication. These side effects were mild to moderate.

A potentially dangerous side effect included amyloid-related imaging abnormalities (ARIA). ARIA is temporary swelling of the brain or small spots of bleeding on the surface of the brain. Larger areas of bleeding can occur. Most people with ARIA did not experience symptoms. People with ARIA who did have symptoms experienced headache, confusion that got worse, dizziness, vision problems, nausea, difficulty walking, and seizures.

Conclusion

The study results suggest that lecanemab may offer benefit to patients with early Alzheimer’s disease by slowing cognitive decline and reducing amyloid plaque. However, long-term safety and effectiveness require further investigation.

My Thoughts

With any medication or treatment, the risks vs benefits need to be thought through. Do the benefits that are helpful outweigh the risk of unwanted or unexpected effects? In this study, lecanemab has been shown to have modest benefit for people with early Alzheimer’s disease. The risk of lecanemab is ARIA. Any time brain swelling or bleeding is involved there are serious consequences, even death. Does this moderate benefit justify the risks associated with this? Another concern is that many people with dementia or early Alzheimer’s may not qualify for treatment due to a history of heart disease, stroke, cancer, or previous brain injuries. Last, we do not fully understand long-term effects of using this medication, Alzheimer’s is lifelong, and this study was for only 18 months. Do we continue to use this medication over the approved length of time?

If you or someone you know is diagnosed with Alzheimer’s disease and are looking for treatment. It is important to talk to your doctor about what options are best and appropriate for you. Remember a pharmacist will be available to help walk through medications too!  If you have questions regarding this post please reach out.

Prepared by Adam Taniguchi PharmD

Resources:

1. 2023 Alzheimer’s disease facts and figures. Alzheimers Dement. 2023;19(4):1598-1695. doi:10.1002/alz.13016
2. Cohen S, van Dyck CH, Gee M, et al. Lecanemab Clarity AD: Quality-of-Life Results from a Randomized, Double-Blind Phase 3 Trial in Early Alzheimer’s Disease. J Prev Alzheimers Dis. 2023;10(4):771-777. doi:10.14283/jpad.2023.123
3. https://www.nia.nih.gov/health/alzheimers-treatment/how-alzheimers-disease-treated#:~:text=Medications%20for%20mild%20to%20moderate%20Alzheimer’s%20disease,-Treating%20the%20symptoms&text=Galantamine%2C%20rivastigmine%2C%20and%20donepezil%20are,some%20cognitive%20and%20behavioral%20symptoms.
4. https://www.nia.nih.gov/health/alzheimers-and-dementia/what-alzheimers-disease
5. https://www.alz.org/alzheimers-dementia/research_progress/milestones#:~:text=Aducanumab%20(Aduhelm%C2%AE)%20received%20accelerated,underlying%20biology%20of%20Alzheimer’s%20disease.