Alzheimer's Drug Proven To Slow Cognitive Decline, Side Effects Raise Concerns

An experimental Alzheimer's disease drug from Eisai and Biogen has observed slowed cognitive decline in a closely watched trial in patients with early stages of the disease

An experimental drug called lecanemab from Eisai and Biogen has observed slowed cognitive decline in a closely watched trial

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In a major breakthrough in the fight against Alzheimer’s, a clinical trial confirmed that a drug slows cognitive decline in patients with early stages of the disease.

The outcome comes after almost decades of trials in the field paving way for the industry to say Alzheimer’s which affects 30 million people worldwide could be treatable.

“This is the first drug that provides a real treatment option for Alzheimer patients,” said Bart De Strooper, director of the UK Dementia Research Institute at University College London, The Guardian reported.

What’s the experimental drug?

An experimental Alzheimer's disease drug called lecanemab from Eisai and Biogen has observed slowed cognitive decline in a closely watched trial. However, it may carry a risk of dangerous side effects for certain patients, according to new data presented on Tuesday, news agency Reuters reported. Eisai is a Japanese pharmaceutical company and Biogen is an American biotechnology company.

In September, the company announced the 18-month-long trial that comprised nearly 1,800 participants with early-stage Alzheimer's analysed that treatment with lecanemab reduced the rate of decline on a clinical dementia scale (CDR-SB) by 27 per cent compared to a placebo, the report added.

APOE4 carriers, or the people with APOE4 genes, did show improvement on the trial's secondary goals, including other measures of cognition and daily function. APOE4 is the strongest risk factor gene for Alzheimer's disease. Overall, lecanemab patients benefited by 23 per cent to 37 per cent compared with a placebo on these secondary trial goals.

"All of these amyloid-lowering drugs carry a risk for an increased brain hemorrhage," the report quoted Dr Ronald Petersen of the Mayo Clinic in Rochester, Minnesota, as saying. "I think the primary outcomes, the secondary outcomes, the amyloid-lowering is pretty impressive." Amyloids are a group of proteins that are linked to the occurrence of various diseases in human beings.

The Alzheimer's Association has called on US regulators to approve the company's application for accelerated approval. The association said the data confirms the drug "can meaningfully change the course of the disease for people in the earliest stages of Alzheimer’s disease."

What are the side effects of the drug?

The drug is linked to a type of brain swelling in 12.6 per cent of trial patients, a similar side effect seen with other similar drugs in the past. Around 14 per cent percent of patients had microhaemorrhages in the brain, a condition linked to two recent deaths of people receiving lecanemab in a follow-on study - and five patients suffered microhaemorrhages.

The trial showed no benefit on the CDR-SB measure for some patients with a genetic risk of developing the mind-wasting disease.

About 16 per cent of participants had two copies (homozygous) of the APOE4 gene variant known to raise the risk of developing Alzheimer's, 53 per cent had one copy of the gene (heterozygous), and 31 per cent were non-carriers.

Researchers also raised other concerns that may hamper the drug’s adoption.

Lecanemab is costlier between £10,000 and £30,000 per patient a year with such a modest effect, at least over 18 months, that it is unclear whether patients would notice any benefit, The Guardian report noted.

It will now be seen whether the UK’s Medicines and Healthcare products Regulatory Agency and the National Institute for Health and Care Excellence (Nice) approve the drug.