Lots of ‘breakthroughs’, still no cure. Do the new dementia drugs bring us any closer?

Subject :Science and Technology

Context-

What is Dementia?

Dementia is an umbrella term to describe a group of conditions characterised by a loss of brain function; this includes the ability to remember, plan and make decisions.
In Australia, dementia is the second leading cause of death. For women, it’s the leading cause of death.
Older age is the greatest risk factor for dementia. But dementia is not an inevitable or normal consequence of ageing.
Up to 70 per cent of all dementia is attributed to Alzheimer’s disease. Alzheimer first described as an “unusual disease of the cerebral cortex” in 1906.
- In Alzheimer’s disease, Amyloid protein builds up in the brain, which further triggers the development of Tau (a protein) which induces memory loss.
- Beyond amyloid and tau, a range of other biological, genetic, lifestyle, and environmental factors can also contribute to Alzheimer’s disease.
Other types of dementia include vascular dementia, frontotemporal dementia, and Lewy body disease.
Because Alzheimer’s is the most common form of dementia, most “dementia breakthroughs” often refer to “breakthroughs” in Alzheimer’s.

Two new drugs-

Two drugs that have received a lot of attention in recent weeks are aducanumab (marketed as Aduhelm) and lecanemab.
Both drugs showed a substantial reduction in amyloid in the brain. But whether this reduction in amyloid resulted in a meaningful benefit in memory and thinking is less clear.
The Food and Drug Administration in the United States granted accelerated approval for aducanumab as it thought the drug would improve or slow Alzheimer’s symptoms.
Lecanemab resulted in a 27 per cent slower decline in memory and thinking ability.

Major concerns about the drugs

Side effects include- Brain swelling and small brain bleed as detected on brain scans.
High cost of drugs- Aducanumab costs US$28,200 (A$42,000) per patient per year.