Context: 

A pharmaceutical company, Eli Lilly, has released what it calls “positive results” from phase 3 trials for its own candidate Alzheimer’s treatment, donanemab.

About the News:

• Eli Lilly said donanemab had “significantly slowed cognitive and functional decline in people with early symptomatic Alzheimer’s disease.” 
• Eli Lilly has yet to publish the full results, which means the data has not been peer reviewed or independently verified.

Alzheimer’s Disease:

• Alzheimer’s disease is a brain disorder that gets worse over time. 
• It’s characterised by changes in the brain that lead to deposits of certain proteins. 
• Alzheimer’s disease causes the brain to shrink and brain cells to eventually die. 
• It is the most common cause of dementia — a gradual decline in memory, thinking, behaviour and social skills. These changes affect a person’s ability to function.

How does donanemab work?

• Donanemab is not the first of its kind. As with similar antibody-based therapies such as lecanemab, donanemab is not a cure for Alzheimer’s.
• It has antibodies that target different forms of amyloid-beta (Aβ) proteins that can clump together to form amyloid plaques in people’s brains, resulting in their congnitive decline. 
• The drug aims to remove the plaques from the brain and slow the progression of the disease.

How does donanemab compare to lecanemab?

• Eli Lilly’s press release suggests that donanemab slows cognitive decline by 35%. Lecanemab trial results showed it slowed cognitive decline by 27%.
• Both drugs are given intravenously, but the doses are different — donanemab was given every four weeks and lecanemab every two weeks. 
• Both drugs were only tested on people with early stages of Alzheimer’s. 
• It is, therefore, unknown how effective the drugs are for people with more advanced forms of the disease.
• Lecanemab is approved in the US, but it is still under evaluation by the FDA’s counterpart in Europe, the European Medicines Agency (EMA).
• Donanemab is not yet approved for use in either the US or Europe.

News Source: Indian Express