Alzheimer’s disease (AD) is a devastating neurodegenerative disease of the central nervous system which is responsible for 60-80% of all cases of dementia and progressively destroys the cognitive abilities of those who develop the disease.
Very early AD
Mild to moderate AD
As Alzheimer’s disease progresses, neurofibrillary tangles spread throughout the brain. Plaques also spread throughout the brain, starting in the neocortex. By the final stage, damage is wide spread and brain tissue has shrunk significantly.
The World Health Organization recognizes dementia as a global public health priority. Worldwide, there is a new case of dementia every three seconds, with an estimated global patient population of approximately 50 million in 2019. This is predicted to increase to 152 million by 2050 (World Alzheimer Report 2019: Attitudes to dementia). AD is the most common form of dementia, accounting for 60–80% of dementia cases (Alzheimer’s Association). The estimated aggregate cost of prevention and treatments in the United States was USD 1 trillion in 2019 and is estimated by Alzheimer’s Disease International, or ADI, to grow to USD 2 trillion in 2030. ADI estimates the cost of prevention and treatment in the United States could be reduced by 35−40% in 2050 if the onset of AD could be delayed by five years in the patient population. In addition, the prevalence of AD in people with DS is more than 50% over the age of 50 and 75–100% over the age of 60 (Strydom A., et al., Alzheimers Dement (NY), 2018). DS affects approximately one in 1,000 live births worldwide.
It is becoming increasingly clear that AD develops because of a complex series of events that take place in the brain over a long period of time. Two proteins - Tau and amyloid beta (Abeta) - are recognized as major hallmarks of neurodegeneration: tangles and other abnormal forms of Tau protein accumulate inside the brain cells and spread between cells, while plaques and oligomers formed by Abeta occur outside the brain cells of people with Alzheimer’s.
Today though, AD is typically diagnosed by neurologists and psychiatrists through a series of cognitive and functioning tests once symptoms are already clinically present. This results in a diagnosis at later stages of the disease where irreversible loss of neurons has already occurred. An early diagnosis with imaging methods and biomarkers is therefore crucial and is expected to translate into earlier treatment with better outcome for the patients and offer the possibility to look into disease prevention.
Currently approved treatments only include medications that help relieve the symptoms of the disease but do not treat the underlying causes of the disease. The clinical benefit derived is typically incomplete and only improves the patient’s symptoms for a short period of time underlining the urgent medical need of disease modifying treatments. Such disease modifying treatments are expected to have a major impact for the patients as they will considerably slow the cognitive decline. The benefit for the patients will increase if the treatment can start earlier in the disease course, ideally even before symptoms start to appear.
AC Immune’s therapeutic and diagnostic agents are at the forefront of fighting against one of the world’s greatest healthcare challenges – the need to develop reliable and accurate diagnostics and disease modifying treatments to improve the lives of patients suffering from Alzheimer’s and other neurodegenerative diseases.