Can the new Alzheimer’s drug, Lecanemab, be effective enough?

Subject: International relations

Context:

The United States Food and Drug Administration (USFDA) has granted fast-track approval to an Alzheimer’s medicine which, initial results show, reduces the amyloid beta protein deposition in the brain – a classic symptom of the neurodegenerative disease.

Two new drugs that got approval fro US FDA:

Two drugs that have received a lot of attention in recent weeks are aducanumab (marketed as Aduhelm) and lecanemab.
- The drug Lecanemab, marketed as Leqembi, is the second such monoclonal antibody to receive approval from the regulator. (First one is Aducanemab.)
- Its accelerated approval, a protocol used for serious conditions for which not many treatments exist, was based on a “surrogate endpoint” – there was a statistically significant reduction in amyloid beta plaques at week 79 in 856 Alzheimer’s patients who took the medicine, according to the statement from USFDA.
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 and Lecanemab 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.

Concerns:

The results were encouraging only when it was administered to patients with mild cognitive impairment or mild dementia.
There is no evidence yet of its interventionist potential in advanced cases.
Another medicine called Aducanemab, got approval in 2021, and developed by Japanese and American companies Eisai and Biogen, also shows less effective than what it claimed.
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, and the cost of Lecanemab is $26500/ year.

About Alzheimer’s disease:

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.