Alzheimer's Detection and Treatment
Alzheimer's Disease: Prognosis, Diagnostics, and Treatment Pipeline
The Impact of Alzheimer's Disease:
Alzheimer's disease (AD) is an age-related neurodegenerative disease that currently affects 5.7 million people in the United States. Patients with AD appear asymptomatic during early stages of disease onset, often followed by cognitive loss due to hippocampal damage. [1,2] The 2010 U.S. census report estimated that one in ten Americans over the age of 65 is living with AD. [3] On top of the heavy emotional costs of AD, the financial burden of patients over the age of 65 with dementia, is three times higher than the average healthcare cost of other Medicaid beneficiaries without dementia (Table 10 from Ref. 1). With a growing proportion of elderly Americans from the baby boomer generation, new solutions to early detection and treatment of AD is essential.
Diagnosis of AD:
Detection of AD biomarkers can generally be classified into neuroimaging or Cerebral Spinal Fluid/Blood biomarkers. Neuroimaging strategies include PET scans for beta-amyloid deposits, elevated cortical tau, decreased glucose metabolism, and atrophy (structural MRI). [3] CSF or blood biomarkers can assess the clearance (or lack of) from brain tissue and give pathological insight into disease progression. Some current biomarkers include a specific amyloid, phosphorylated and total tau, and more recently the neurofilament light protein. [3] However, it is important to note that most insurance policies do not cover biomarker detection tests. Most initial diagnosis of AD come from cognitive function loss. With earlier detection, steps can be taken to reduce the emotional, social, and financial burden of AD. Financial analysis assessing partial early diagnosis savings on the cost of AD (70% successful diagnosis every two years) is illustrated in Figure 16 from Ref. 3. Partial early detection from improved diagnostic practices can save $31.8 billion dollars in 2025 during mild congition impairment stages according to this model. Recently there has been a large push for effective early diagnosis improvements including a $30 million dollar donation from the Bill and Melinda Gates Foundation. [4,5] Key players in the diagnosis market include Eli Lilly, TauRx, Alector LLC, Accera Inc, Treventis, Neuro-Bio Ltd, and Cognition Therapeutics. [6]
Treatment Strategies and Market Overview:
AD treatments currently aim to enhance cognitive function
temporarily, however no treatments exist to reverse, slow, or prevent AD. [7]
Cholinesterase inhibitors modestly improve cognition function by increasing
choline signaling. Aricept, Razadyne, and Exelon are common cholinesterase
inhibitors prescribed which can be given in combination with Namenda which
blocks a glutamate receptor subfamily (NMDA). [8] These drugs combine for a
$3.64 billion dollar market growing at a CAGR of 8% through 2024. Companies
leading the front in treatment sales include Ono Pharma, Johnson & Johnson,
Daiichi Sankyo, H Lundbeck A/S, and Eisei Co. [9] At UTSW's O'Donnell Jr. Brain
Institute Peter, Dr. Rosenberg has recently developed a DNA vaccine coding for
beta-amyloid that's injected into the skin. In mice, the DNA vaccine showed a
40% reduction in beta-amyloid and 50% reduction in tau. [10] Other immunization
strategies are currently undergoing clinical trials but are passive treatments
rather than the active immunization strategy taken by Dr. Rosenberg's lab.
There are currently 112 pipeline drugs in development for AD which are
summarized further in Ref 11.
References
1. https://www.alz.org/media/HomeOffice/Facts%20and%20Figures/facts-and-figures.pdf
2. https://www.nia.nih.gov/health/alzheimers-disease-fact-sheet
3. Hebert LE, Weuve J, Scherr PA, Evans DA. Alzheimer
disease in the United States (2010-2050) estimated using the 2010 Census.
Neurology 2013;80(19):1778-83.
4. https://www.voanews.com/a/bill-gates-backs-30-million-push-for-early-alzheimer-s-diagnostics/4486677.html
5. https://www.marketwatch.com/story/5-ways-to-help-fight-alzheimers-according-to-bill-gates-2017-11-14
7. https://www.mayoclinic.org/diseases-conditions/alzheimers-disease/diagnosis-treatment/drc-20350453
8. https://www.ncbi.nlm.nih.gov/pubmed/16368266
10. https://www.utsouthwestern.edu/newsroom/articles/year-2018/dna-vaccine-alzheimers.html
11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6021548/