Lecanemab, brand name Leqembi, is the first drug approved in Japan to both treat the underlying causes of Alzheimer's disease and slow the progression of symptoms of the disease.

The drug, which treats early-stage and mild cognitive impairment, is expected to be available as early as the end of this year. However, experts warn that it can cause side effects, some of which are serious.

Previously, a multinational clinical trial showed that 17.3% of people taking Lecanemab experienced brain bleeding compared with 9% of those taking placebo, while brain swelling was observed in 12.6% with Lecanemab and 1.7% with placebo.

Experts say the condition of those treated will need to be carefully monitored, especially if they have other health problems.

In the US, the drug was approved in July, but regulators have required patients to undergo APOE gene testing. People with APOE4, one of three APOE genes, are more likely to develop Alzheimer's. APOE4 is also a risk factor for a type of brain swelling and bleeding called ARIA, caused by the antibody drug. But in Japan, genetic testing will not be required for Lecanemab.

Treatment with Lecanemab will be given as a bi-weekly injection for 1.5 years, with the patient's brain condition monitored via MRI scans.

It is known that the price of medicine in the US is 26,500 USD/year. The price of medicine in Japan is also expected to be high.

Minh Hoa (reported by Vietnam+, Ho Chi Minh City Women's Newspaper)