Japan greenlights Sysmex's amyloid blood test for Alzheimer's disease

On the heels of hopeful clinical trial results for a drug that may work against Alzheimer’s, Japanese regulators have approved a simple blood test to identify potential patients with the hallmark signs of the disease.

Sysmex received a green light within the country for a sensitive, two-step test kit that looks to gauge the ratio between two beta amyloid proteins present in the bloodstream. Typically found in the cerebrospinal fluid, the proteins can be traced back to the amyloid plaques that develop within the brains of people with the neurodegenerative condition.

Previously, analyzing these proteins has required painful and more invasive lumbar punctures or expensive PET scans. Blood tests, by comparison, could be conducted multiple times to track the progression of a single patient or be easily implemented on a much broader scale.

At the same time, earlier diagnoses of Alzheimer’s, such as after the first signs of mild cognitive impairment, could lead to earlier treatments that may save trillions of dollars in healthcare costs, according to a report from the U.S. Alzheimer’s Association. 

Kobe-based testmaker Sysmex has been working with its fellow Japanese biotech Eisai, headquartered in Tokyo, on a blood-based diagnostic approach for biomarkers in dementia since 2016

Eisai made waves this year with its anti-amyloid antibody lecanemab, developed through a collaboration with Biogen, after the drug cleared a phase 3, placebo-controlled trial in September. Lecanemab slowed cognitive decline by 27%, but later releases of data pointed to two patient deaths during the study, both from brain bleeds. 

Previously, in late 2021, Japanese regulators refused to approve lecanemab’s predecessor, Eisai and Biogen’s controversial Aduhelm treatment—less than a week after that Alzheimer’s drug also received a rejection from the European Medicines Agency.

Sysmex first submitted its amyloid blood test—the HISCL β-Amyloid 1-42 and 1-40 assay kits, which run on the company’s automated immunoassay systems—to Japan’s Pharmaceuticals and Medical Devices Agency in December of last year. The company said it requires 10 microliters to 30 microliters of blood and can deliver measurements in 17 minutes.

In the U.S., the FDA cleared its first in vitro test for the early detection of Alzheimer’s disease this year. Though the Lumipulse assay, developed by Fujirebio Diagnostics, relies on cerebrospinal fluid and not blood plasma, the agency said the test could typically deliver a result in one day and allow some patients to avoid PET scans.

Meanwhile, 2022 also saw Roche receive a breakthrough designation from the FDA for its in vitro Alzheimer’s test—an amyloid plasma panel that also measures blood levels of phosphorylated tau 181 and apolipoprotein e4, two biomarkers that have also been linked to a person’s risk of the disease.

And prior to that, C2N Diagnostics—which has also received research funds from Eisai—demonstrated that its PrecivityAD blood test could perform nearly on par with PET scans. The company is moving forward with a 1,100-participant study that will use the blood test to screen people as young as 55 years old for high amyloid levels, and it has also launched a separate tau-based blood test.