TOKYO — U.S. regulators’ approval on Monday of aducanumab, an Alzheimer’s treatment jointly developed by California-based Biogen and Tokyo-based Eisai, is potentially a life-changing moment for millions.
This is the first time that the U.S. Food and Drug Administration has approved a drug designed to slow the progress of Alzheimer’s in sufferers. Previous drugs targeting the disease have aimed only to alleviate symptoms.
It has raised hopes that dementia, a pressing challenge in countries with aging populations, can better be dealt with. In Japan, an estimated 6 million people are suffering dementia, or 17% of the senior population. Alzheimer’s is the most common form of dementia, accounting for nearly 70% of cases.
But approval of aducanumab has also been contentious. Is the treatment going to wipe out the disease? How does it work? Here are five things to know.
How does aducanumab work?
Alzheimer’s is a disease that causes memory loss and makes it difficult to carry out daily activities or even to speak. The exact cause is unknown, but scientists believe that a protein called beta amyloid is a major cause. As amyloid increases in the brain, it starts forming fibers and then plaques, damaging nerve cells and causing them to die, according to Eisai.
Aducanumab is a monoclonal antibody that targets amyloid, allowing the body to reduce it in the brain. The human body is capable of removing amyloid, but the ability declines with age, Eisai says.
The drug is found to be effective especially when it is used for early-stage patients, according to Eisai, so it is important that the disease is detected early.
Will it eliminate Alzheimer’s?
This is the big question. The FDA gave aducanumab an accelerated approval, meaning that Biogen will still need to prove the drug’s effectiveness in a post-market study. This is because the results of the earlier trials were not as compelling as the drugmakers hoped them to be — one of the reasons why approval for the drug was in doubt.
Under the scheme, patients will be allowed to use the drug even though there is still residual uncertainty regarding its efficacy. The approval can be withdrawn if it fails to show its effectiveness in a post-market study.
Price could also be a hurdle for broad adoption. Biogen said on Monday that the drug’s list price would be $56,000 a year for an average U.S. patient. The high price tag is likely to limit the users of the drug to those who have an insurance policy that can cover such expensive drugs in the U.S.
In Japan, the drug, if approved, would be covered by the national health care insurance. Given the tight fiscal situation of the Japanese government, access to the drug could be limited to those who are found to have a high level of amyloid, for instance, a drug analyst at a Japanese brokerage house said.
For that, the patient needs to receive a brain scan, but such equipment is not widely available and receiving a test is expensive, the analyst said.
But the analyst expects that demand for the drug will be “very strong.”
What has Eisai’s role been?
Eisai is a Japanese drugmaker founded in 1941. The current CEO, Haruo Naito, is a grandson of the founder and is known for strong leadership and a top-down management style.
He has made Eisai focus on two areas, Alzheimer’s disease and cancer. Under his leadership, Eisai has emerged as a strong developer of innovative drugs.
The company has developed Aricept, a treatment of Alzheimer’s disease symptoms.
Eisai joined Biogen’s project to develop aducanumab in 2014. Development was risky and analysts say Eisai would not have pursued such a project without Naito’s personal commitment.
How has the market reacted?
The news of the U.S. approval took the market by surprise. Shares of Eisai ended up 19% on Tuesday, the biggest gainer on the Tokyo Stock Exchange’s first section. In the U.S., shares in Biogen rose more than 50% at one stage and ended the day up 38% at their highest level in six years.
The steep rises reflect the degree of uncertainty over whether the drug would receive U.S. approval.
“It was like hitting a grand slam in the back of the ninth inning,” the Japanese analyst said.
What happens next?
Attention will now center on further required regulatory approval for aducanumab in other markets, and on whether other drugs that use similar science can be developed.
Eisai filed in December for separate approval in Japan. “We’d like to make the drug available to Japanese patients as soon as possible,” a spokesperson said.
Eisai is also developing, with Biogen, a similar treatment called lecanemab or BAN2401. Lecanemab is also used for removing amyloid at an early stage of Alzheimer’s. The company plans to file for approval for lecanemab in the next fiscal year starting in April 2022.
