The FDA approved a new drug for Alzheimer's disease, which can slow cognitive decline, but the side effects are controversial

The FDA approved a new Alzheimer's disease, lecanemab, designed to slow cognitive decline in patients with mild and early Alzheimer's disease, at a cost of $26,500 per year, a price well below the $56,000 per year price of the last FDA-approved Alzheimer's drug
, aducanumab.

Lecanemab, also developed by Eisai and Biogen, is based on a Phase III clinical trial published November 29, 2022 in the New England Journal of Medicine (NEJM), which showed that it slowed cognitive decline by 27%
in Alzheimer's patients.

However, adverse effects in the results of the clinical trial were controversial, with 17.
3% of patients treated with the modified drug developing intracerebral hemorrhage (9% in the placebo group) and 12.
6% developing brain swelling (1.
7% in the placebo group).

However, the FDA approved the drug for marketing
.

On June 7, 2021, the FDA announced accelerated approval for the marketing of aducanumab (trade name Aduhelm), a monoclonal antibody jointly developed by Eisai and Biogen, for the treatment of mild cognitive impairment (MCI) and mild Alzheimer's disease
in Alzheimer's disease.
This is the first new drug approved by the FDA since 2003 for the treatment of Alzheimer's disease, and the first drug to stop the progression of
the disease.

aducanumab

Aducanumab was immediately controversial after it was approved by the FDA, with clinical trials showing that the monoclonal antibody could clear β-amyloid (Aβ) from the brain, but there was not enough evidence to slow or stop the progression
of Alzheimer's disease 。 In addition, there was a risk of side effects, with 425 patients (41.
3%) experiencing amyloid-related imaging abnormalities (ARIA) and 362 patients (35.
2%) experiencing ARIA cerebral edema in the 10 mg/kg dose group, and 94 of them experiencing associated symptoms such as headache, confusion, dizziness, and nausea
.
197 patients (19.
1%) developed ARIA microbleeding and 151 patients (14.
7%) developed ARIA surface iron deposits
.
Of these patients, 14 experienced side effects in severe
condition.

On November 29, 2022, the results of a Phase 3 clinical trial of lecanemab, another Alzheimer's drug developed by Eisai and Biogen, were published in the New England Journal of Medicine (NEJM), which showed that the new Alzheimer's disease drug moderately slowed the progression
of Alzheimer's disease.

Unlike aducanumab, lecanemab is a humanized IgG1 monoclonal antibody that works by binding to β-amyloid (Aβ), which is an Aβ monoclonal antibody
.

The patients with early-stage Alzheimer's disease received either lenemab or placebo intravenously every two weeks for 18 months, and the researchers measured their cognitive abilities
on an 18-point scale.
The results showed that lecanemab delayed the patient's deterioration by about 5 months
.
In addition, patients who received lecanemab were 31 percent less likely to progress to the next stage of the disease during the study period
.
But doctors are divided
on how much these changes will affect patients and families.

But Dr.
Ron Petersen, an Alzheimer's specialist at Mayo Clinic, believes the drug doesn't work much, but it makes clinical sense
.
Because even a few months of delaying disease progression can give Alzheimer's patients a little more time to live/work independently
.

Maria Carrillo, chief scientist at the Alzheimer's Association, said the clinical trial is important because it shows that targeting amyloid with drugs can delay Alzheimer's progression, and we all know it's not a cure for Alzheimer's disease, and we're all trying to really understand what
it means to slow down Alzheimer's.

Maria Carrillo also said that delaying cognitive decline in the early stages of Alzheimer's disease is important, allowing patients to spend more time with loved ones, enjoy family life more, travel, vacation, and complete bucket lists
.

Drugs that target Abeta can cause side effects including brain swelling and intracerebral hemorrhage, and lecanemab is no exception, with about 13 percent of recipients experiencing one type of swelling
.
But Eisai says most patients have mild or no symptoms
.

In addition, there are publicly reported two deaths in clinical trials of lecanemab, raising concerns about
the drug's tolerability and safety.
Eisai said the two died from taking blood-thinning drugs for other health problems, so the deaths could not be attributed to Alzheimer's disease medications
.

There are tens of millions of people living with Alzheimer's disease worldwide, but there are only a few treatments or drugs, and at best temporary relief of symptoms
.
In fact, scientists still don't know exactly how Alzheimer's disease develops, and some theories suggest that the accumulation of β-amyloid (Aβ) plays a key role in the development of Alzheimer's disease, but drugs that target Aβ have rarely succeeded
.

Last year, the FDA approved aducanumab, the world's first Aβ-targeting drug, but the actual efficacy lacked evidence and the price was so high ($56,000/year) that doctors were reluctant to prescribe the drug
to Alzheimer's patients.