Background


Prevalence


Current Treatments



Background


Alzheimer's disease is characterized by a progressive deterioration of mental faculties, usually beginning with memory loss and developing further with disturbances in reasoning, language, and personality. Patients can expect approximately eight years between initial presentation of symptoms and fatality, but the disease has usually progressed significantly by the time any symptoms appear. Advanced symptoms are widely believed to be caused by the inflammation and death of nerve cells resulting from an overabundance of beta-amyloid plaques and tau neurofibrillary tangles. However, the causal relationships between these players are not fully understood.



Prevalence


The Alzheimer's Association estimates that 5.2 million Americans have Alzheimer's disease (2014 Alzheimer's Disease Facts and Figures). The vast majority of these individuals (82%) are over age 75 with prevalence of 11% of all people over the age of 65 and 32% of those over age 85. For unaffected individuals at age 65, the risk of developing the disease in the remainder of life is 17% for men and 20% for women. According to the Centers for Disease Control and Prevention (CDC), Alzheimer's disease accounts for approximately 85,000 deaths in the United States each year, making it the sixth most common cause of death. However, a recent study from Rush University suggests the number is significantly higher--closer to 500,000, which would make Alzheimer's disease the third leading cause of death, trailing only heart disease and cancer.


By far the greatest risk factor for the development of Alzheimer's disease is age. The prevalence of the disease doubles every five years after age 65. Thus, the number of individuals diagnosed with Alzheimer's disease is driven primarily by age demographics. In 2011, the oldest members of the baby-boom generation turned 65. Over the next 20 years, the 75 million members of this generation will cross this threshold. Thus, unless disease-modifying treatments are developed, the projected number of Americans living with Alzheimer's disease will increase to 5.8 million by 2020, 8.4 by 2030, and a staggering 13.8 million by 2050. Mental illnesses which impair memory and cognition represent an immense economic and social burden. Alzheimer's disease currently inflicts an annual cost of $203 billion in the United States, a number that will grow to more than $1 trillion by 2050.




Current FDA-Approved Treatments


Drug Name Brand Name
(Company)
Peak
US Sales
Year Approved
(For Stages)
Generic Class Structure
Donepezil Aricept
(Pfizer/Eisai)
$2,514M
(2010)
1996
(All Stages)
Yes Cholinesterase Inhibitor
Memantine Namenda
(Forest/Allergan)
$1,521M
(2013)
2003
(Moderate
to Severe)
Yes
NMDA Receptor Antagonist
Rivastigmine Exelon
(Novartis)
$457M
(2013)
2000
(Mild to
Moderate)
Yes Cholinesterase Inhibitor
Galantamine Razadyne
(J&J)
$247M
(2004)
2001
(Mild to
Moderate)
Yes Cholinesterase Inhibitor