"Father, You Can Breathe Easier Now" From 1 Hour to 15 Seconds...A Dramatic Shift in Treatment Settings [The New Path for Dementia Treatment]①

Diagnosis by PET Scan Now Possible with an 18-Minute Blood Test

One-Hour IV Infusion Replaced by 15-Second Self-Injection

"Significant Expansion of Treatment Demand at Local Clinics"

Editor's NoteA revolutionary breakthrough in Alzheimer's treatment is imminent. In the near future, expensive brain imaging—which previously required a two-month wait—could be replaced by simple blood tests, and intravenous treatments that used to tie patients to a hospital for an hour every two weeks could soon be swapped for self-administered injections that take just 15 seconds. Once these physical, spatial, and time barriers to diagnosis and treatment are overcome, the target group expands from dementia patients to “ordinary people who have no symptoms yet but are at risk.” However, there are still no sufficient testing infrastructures to accommodate this, no standards to filter out false positives, and no reimbursement system to divide the costs. The Asia Business Daily examines how this paradigm shift in dementia treatment will unfold and what needs to be done to prepare.

① Treatment Conditions Change: Two Months Waiting for Tests, One Hour for Infusion—Soon to be Overhauled

② Blood Tests and SC Formulations: “A Window of Opportunity” for Korea's Bioindustry

③ Surge in Demand Anticipated—But Addressing False Positives and Reimbursement Challenges Is Key

Recently, a man in his 60s (referred to as Mr. A) began repeatedly forgetting appointments and asking the same questions, prompting his family to advise him to see a local doctor. The doctor recommended a detailed examination, so he made an appointment with a university hospital's neurology department. In order to use Alzheimer's medication, doctors must confirm whether amyloid protein has actually accumulated in the brain, which requires a positron emission tomography (PET) scan. This test involves injecting a radioactive tracer that binds to amyloid in the brain and then taking images. Mr. A was scheduled for the scan two months later.

After a long wait, Mr. A finally received the decision to start Alzheimer's drug therapy. However, to him, the complicated and lengthy treatment schedule seemed more daunting than the decision itself. Before the treatment, the initial patient briefing alone—explaining potential side effects and dosing schedule—takes 30 to 40 minutes. The drug is administered intravenously, blended with a 250ml solution over the course of one hour. After that, patients must return to the hospital every two weeks to repeat the entire process. Periodic magnetic resonance imaging (MRI) scans are also needed to check for any brain edema or hemorrhage.

Sung-Hoon Kang, director of the Alzheimer's Prevention Center at Korea University Guro Hospital, is talking with a patient undergoing an examination. Korea University Guro Hospital

This convoluted process is expected to change drastically within a year. Technologies that can overhaul both diagnosis and administration methods are sequentially being introduced into Korea. According to Sung-Hoon Kang, Director of the Alzheimer’s Prevention Center and Professor of Neurology at Korea University Guro Hospital, on September 9, “What has actually hindered the expansion of treatment was not the drug’s efficacy or safety, but the waiting time for diagnostic scans and access to infusion rooms. If blood tests replace the PET scan step and subcutaneous injections reduce the burden on infusion rooms, diagnoses and treatments could be conducted outside of university hospitals.” Korea University Guro Hospital’s Alzheimer’s Prevention Center ranks among the top three major hospitals in Korea in terms of Leqembi (generic name: lecanemab) prescription numbers. The cumulative number of patients treated reached 240 as of the first half of this year.

The dramatic increase in demand for Alzheimer’s therapy has occurred only in the past two years. The prescription of Leqembi, which removes amyloid plaques, began in Korea in December 2024. Until then, even confirmation of amyloid buildup in the brain was of limited clinical value, as there was no way to slow disease progression, leading to low demand for such diagnostic tests.

Although the hypothesis that amyloid is the cause of Alzheimer’s was proposed in the early 1990s, no drug specifically targeting it was available for thirty years. Experimental drugs like Pfizer and Johnson & Johnson’s bapineuzumab, Eli Lilly’s solanezumab, and Roche’s gantenerumab repeatedly failed to demonstrate cognitive improvement in phase 3 clinical trials. In 2021, Biogen’s aducanumab received conditional approval in the United States, but the evidence fell short of proving cognitive benefit, only demonstrating amyloid reduction as a surrogate marker—sales were discontinued in 2024. Leqembi broke this pattern in its 2022 phase 3 trial, showing a 27 percent slowing in cognitive decline by targeting the earliest forms of amyloid aggregation.

18-Minute Blood Test, Weekly Subcutaneous Injection: Improving Accessibility from Diagnosis to Administration

The most immediate advance is the introduction of a blood test within the year. This test measures phosphorylated tau protein (p-tau181) levels in the blood. Tau proteins are responsible for structural support inside nerve cells. When amyloid begins to accumulate in the brain, tau proteins become phosphorylated and are released into the bloodstream in this altered form. Measuring the concentration of this altered protein allows for an indirect assessment of the brain’s state. Although it is not accurate enough for definite diagnosis, it is effective as a screening test—if the value falls below a certain threshold, the absence of amyloid can be assumed, enabling efficient selection. This test can be administered not only at major hospitals, but also through local clinics by drawing blood and sending it to commercial labs.

In the second half of next year, another blood test will be introduced, which also measures phosphorylated tau but at a different site: the p-tau217 test. This can distinguish amyloid buildup with 90 to 95 percent accuracy. The Elecsys p-tau217 test by Roche, which was approved in the United States last month, delivers results in as little as 18 minutes after loading the sample into the analyzer. Currently, blood samples can be sent to the U.S. for testing, but most hospitals do not use this option as it takes more than a month to receive results and the test is not yet approved in Korea. Once introduced here, results could be available within a few hours after sample collection.

The options for therapy are also expanding. By the end of this year, domestic approval is anticipated for donanemab, the second amyloid-targeting drug in this class. Next year, subcutaneous Leqembi formulations are expected to be approved and introduced as well. These can be administered once a week; each injection takes about 15 seconds, drastically reducing time spent in the infusion room compared to intravenous therapy. Next-generation drugs are also under development—Roche’s trontinemab is designed to improve blood-brain barrier penetration by a factor of ten. Its goal is to shorten the treatment period from the current 18 months to 6 months, with phase 3 trials ongoing.

Concerns about side effects, which hindered early adoption, are being mitigated by real-world data. According to a research team at Korea University Guro Hospital, out of 197 patients who received at least five doses, 20 (10.1 percent) experienced amyloid-related imaging abnormalities (ARIA), of which 19 were asymptomatic. A recent study published in the international journal Alzheimer’s & Dementia found a similarly low 8.8 percent ARIA occurrence among 127 subjects, with most cases being mild.

Professor Kang anticipates that within five years, blood tests will be included in Korea’s national health checkups. He explains, “Just as tumor markers in cancer screening trigger further tests such as CT scans or endoscopy, PET scans will be performed only for those with abnormal blood test results, forming a new diagnostic path.”

This content was produced with the assistance of AI translation services.