U.S. FDA Fully Approves Eisai-Biogen Alzheimer’s Drug, Japanese Regulatory Authority to Decide by Autumn

By Yusuke Tomiyama / Yomiuri Shimbun Correspondent

20:00 JST, July 7, 2023

WASHINGTON — The U.S. Food and Drug Administration on Thursday fully approved a new drug for the treatment of Alzheimer’s disease jointly developed by Eisai Co. of Japan and Biogen Inc. of the United States.

A review by Japan’s drug regulatory authority is expected to be completed by autumn.

Lecanemab is the first drug proven to be effective in slowing the progression of Alzheimer’s by removing a substance believed to cause the disease.

With the FDA’s approval, the drug will be covered under Medicare, public medical insurance for the elderly in the United States. Eisai expects more than 10,000 people to be using the drug by the end of March next year.

Eisai has also submitted applications to market the drug in Japan, the European Union, China, Canada, Britain and South Korea.

Lecanemab slows the progression of dementia by removing amyloid-beta, an abnormal protein that accumulates in the brains of patients with Alzheimer’s. The drug will only be administered to patients in the early stages of the disease.

The mechanism of the drug is fundamentally different from that of conventional dementia medications, which are aimed at temporarily improving symptoms by activating brain signal transmissions.

In January, the FDA granted lecanemab accelerated approval based on the results of interim clinical trials. Subsequently, Eisai submitted additional results from the final stage of clinical trials, which found that the drug reduced cognitive decline by 27%, and the FDA continued its review.

“Today’s action is the first verification that a drug targeting the underlying disease process of Alzheimer’s disease has shown clinical benefit in this devastating disease,” the FDA stated Thursday when the drug’s approval was announced.

It also noted that side effects include headache and temporary swelling of the brain, and warned of higher risks of intracerebral hemorrhage, particularly among people taking anticoagulants.

Eisai has set the U.S. sales price for Leqembi — lecanemab’s brand name in the country — at $26,500 per patient per year (about ¥3.8 million).

The result of Japan’s review will likely be released by autumn. The government will set the price if the drug is approved by health insurance. Japanese drug prices are generally lower than those in the United States, but lecanemab is still expected to cost millions of yen per person annually in Japan.

Patients aged 70 or older with annual incomes of ¥1.56 million-¥3.7 million will have to pay up to ¥144,000 per year under the government’s high-cost medical expense benefit system.

Alzheimer’s disease is estimated to account for 60% to 70% of all dementia cases. It is believed that 10 to 20 years before symptoms appear, amyloid-beta accumulates in patients’ brains, damaging neurons and causing brain atrophy.

The World Health Organization estimates about 55 million people worldwide have dementia. In Japan, the number is predicted to reach 7.3 million by 2025.

“The drug’s official approval in the United States will accelerate discussions on its review in Japan and other countries,” said Manabu Ikeda, a professor of psychiatry at Osaka University and an expert on dementia treatment. “Front-line medical staff must also expedite preparations, including the creation of a testing system for the new drug and the training of personnel to deal with side effects, such as brain swelling, that have been reported in clinical trials.”