What is Alzheimer’s?

Overview of Alzheimer’s Disease

Alzheimer’s disease is a progressive neurodegenerative condition characterized by the loss or destruction of neurons in the brain. As of 2021, approximately 55 million individuals worldwide are affected by Alzheimer’s or other forms of neurodegenerative dementia. Neurons serve as the primary cells responsible for transmitting information within the brain.

Early Symptoms of Alzheimer’s

The initial signs of Alzheimer’s may include:
– Difficulty remembering the location of items or their usual places
– Challenges in finding common words
– Impairments in intellectual functions

Research indicates that the disease is prompted by the accumulation of protein fragments known as tau and beta-amyloid in the brain. It is important to note that Alzheimer’s is not an inevitable aspect of aging, and early detection can significantly enhance health outcomes.

Exploring Alzheimer’s Treatments

Aducanumab

Aducanumab is designed to target the underlying causes of Alzheimer’s rather than merely alleviating its symptoms. In 2021, the U.S. Food and Drug Administration (FDA) approved aducanumab, marking it as the first new treatment for Alzheimer’s since 2003. While pharmaceutical interventions aim to improve patients’ quality of life and reduce symptoms, it is crucial to understand that Alzheimer’s remains without a cure.

The approval of aducanumab was met with controversy. The FDA’s advisory committee noted that the clinical trial data did not conclusively demonstrate a slowdown in cognitive decline, primarily due to the premature termination of the trials. This early termination was based on the low likelihood of the drug exhibiting cognitive benefits, with only one subgroup showing a reduction in cognitive decline, prompting Biogen to reassess the data for FDA approval.

Lecanemab

In September 2022, a new drug candidate, lecanemab, entered the market, showing promise in slowing cognitive decline associated with Alzheimer’s disease. Clinical trials of lecanemab demonstrated significant results in a large late-stage study. This medication works by clearing the protein clumps linked to Alzheimer’s from the brain.

Unlike aducanumab, lecanemab’s clinical trials proceeded without interruption and yielded statistically significant results in slowing cognitive decline. Both medications reported adverse events related to brain swelling; however, lecanemab had a lower incidence (20%) compared to aducanumab (40%). The FDA is currently reviewing lecanemab for accelerated approval based on the promising results from phase two trials.

Conclusions

While these medications do not offer a cure for Alzheimer’s, they provide hope for patients by helping to preserve independence and cognitive function. Although lecanemab has shown encouraging results, it has yet to receive FDA approval. In contrast, aducanumab’s approval is under the accelerated approval pathway, intended for serious medical conditions with unmet needs.

Addressing Alzheimer’s may require a multi-targeted approach to tackle the various proteins involved in its progression. Additionally, individuals with Alzheimer’s need support beyond medication, including educational initiatives and guidance for managing the disease’s progression, even in the context of FDA approvals.

References

1. Gauthier S, Rosa-Neto P, Morais JA, & Webster C. 2021. World Alzheimer report 2021: Journey through the diagnosis of dementia. London, England: Alzheimer’s Disease International. https://www.alzint.org/u/World-Alzheimer-Report-2021.pdf
2. Alzheimer’s Association. 2019 Alzheimer’s disease facts and figures. Alzheimer’s & Dementia. 2019;15:321-387. https://alz.org/media/Documents/alzheimers-facts-and-figures-2019-r.pdf
3. FDA grants accelerated approval for Alzheimer’s drug. U.S. Food and Drug Administration. https://www.fda.gov/news-events/press-announcements/fda-grants-accelerated-approval-alzheimers-drug
4. Mullard A. Landmark Alzheimer’s drug approval confounds research community. Nature (London). 2021;594:309-310.
5. Salloway S, Chalkias S, Barkhof F, et al. Amyloid-related imaging abnormalities in 2 phase 3 studies evaluating aducanumab in patients with early Alzheimer disease. JAMA Neurol. 2022;79(1):13-21. doi:10.1001/jamaneurol.2021.4161
6. Prillaman M. Alzheimer’s drug slows mental decline in trial – but is it a breakthrough? Nature (London). 2022;610:15-16.
7. Center for Drug Evaluation and Research. 2021. Aducanumab (marketed as Aduhelm) information. U.S. Food and Drug Administration. https://bit.ly/3TLajrj