Alzheimer’s Disease

• 17 May 2023

Why in News?

After the US Food and Drug Administration (FDA) granted “accelerated” approval for a drug to treat Alzheimer’s disease, developed by Biogen and Eisai and called lecanemab, another pharmaceutical company, Eli Lilly, has released its own candidate Alzheimer’s treatment, donanemab.

• Donanemab is currently not approved for use in either the US or Europe.

What is Donanemab and Lecanemab?

• About:
  • Donanemab belongs to a class of antibody-based therapies that target amyloid-beta (Aβ) proteins. These proteins can form amyloid plaques in the brain, leading to cognitive decline.
    • Donanemab aims to remove these plaques and slow the progression of the disease.
    • Lecanemab belongs to a class of drugs called monoclonal antibodies. These antibody-mediated drugs also target beta amyloid and disrupt cell function.
• Safety Concerns and Side Effects:
  • Both donanemab and lecanemab carry a high risk of side effects, including amyloid-related imaging abnormalities (ARIA), such as brain swelling or bleeding.
  • Tragically, three patients in the donanemab trials lost their lives due to these side effects.

What is Alzheimer’s Disease?

• About:
  • Alzheimer's disease is a progressive neurodegenerative disorder that affects the brain, leading to memory loss, cognitive decline, behavioral changes, problems with words in speaking or writing, poor judgment, changes in mood and personality, confusion with time or place, etc.
  • Alzheimer's disease is the most common cause of dementia, accounting for 60-80% of dementia cases.
• Causes and Risk Factors: Currently the causes of Alzheimer is not fully known, still factors that may contribute to Alzheimer’s include:
  • Age: Advancing age is the primary risk factor, with the majority of cases occurring in individuals over 65.
  • Genetics: Certain gene mutations, such as those in the APP, PSEN1, and PSEN2 genes, can increase the risk of developing Alzheimer's.
  • Amyloid Protein: Alzheimer's disease is thought to be caused by the abnormal build-up of amyloid-beta and tau proteins in and around brain cells.
    • Amyloid-beta protein clumps together to form plaques between nerve cells in the brain, while tau protein forms twisted tangles inside neurons.
  • Lifestyle Factors: Chronic conditions like cardiovascular disease, diabetes, obesity, smoking, and a sedentary lifestyle may contribute to the risk.
• Diagnosis:
  • Cognitive and neuropsychological tests to assess memory, thinking, and problem-solving abilities.
  • Imaging techniques (MRI, PET scans) to identify brain changes.
  • Biomarker tests (cerebrospinal fluid analysis, amyloid PET) to detect amyloid plaques.
• Treatment and Management:
  • There's currently no cure for Alzheimer's disease. But there is medicine and supportive therapies available that can temporarily reduce the symptoms.
• Prevalence:
  • Alzheimer's disease affects a significant number of people worldwide, with at least 55 million individuals suffering from the condition.
  • In India, As India’s population ages, the number of people with dementia and Alzheimer’s is set to rise to 7.6 million by 2030.

Dementia

• Dementia is an umbrella term that refers to a group of symptoms characterized by a decline in cognitive abilities severe enough to interfere with daily functioning.
• Dementia is currently the seventh leading cause of death and one of the major causes of disability and dependency among older people globally.

Source: IE