Partnership Aims to Bring Blood-Based Alzheimer’s Testing to Japan

Alzheimer’s disease remains a growing diagnostic challenge as populations age and cognitive impairment becomes more common. In Japan, government-supported estimates project that approximately 4.72 million people aged 65 and older are living with dementia in 2025, with another 5.64 million experiencing mild cognitive impairment. A new partnership now aims to bring a blood-based Alzheimer’s disease test to Japan through a regulated clinical diagnostics pathway.

C2N Diagnostics and LSI Medience Corporation have formed a strategic partnership to seek regulatory approval and commercialize the PrecivityAD2 test in Japan. The collaboration combines C2N’s expertise in high-resolution mass spectrometry for Alzheimer’s diagnostics with LSI Medience’s clinical laboratory, regulatory, and commercial capabilities in Japan. 

In the United States, PrecivityAD2 is FDA-cleared for adults aged 40 and older with signs or symptoms of cognitive impairment undergoing evaluation for Alzheimer’s disease or other causes of cognitive decline. The test is intended to complement clinical assessment rather than serve as a screening or stand-alone diagnostic tool.

PrecivityAD2 uses high-resolution mass spectrometry to measure two blood biomarker ratios: the amyloid-related Aβ42/40 ratio and the percentage of phosphorylated tau 217 (%p-tau217). These measurements are combined into a single score indicating the likelihood of Alzheimer’s disease-related amyloid pathology in the brain.

U.S. FDA clearance was supported by a clinical validation study involving 1,142 participants, with results compared against amyloid positron emission tomography (PET) or cerebrospinal fluid biomarkers. Positive PrecivityAD2 results correctly identified amyloid pathology 97.6% of the time, while negative results were correct 93.1% of the time. Likely positive results occurred in 17.3% of participants and had a positive predictive value of 77.3%.

The test demonstrated consistent performance across the clinical stages, age groups, and chronic disease subgroups evaluated in the study. The partnership with LSI Medience also builds on C2N’s existing relationship with PHC Group in Japan, where Mediford Corporation has supported Precivity testing for biopharmaceutical and clinical research since 2024. The new collaboration aims to extend access to the technology through a regulated clinical diagnostics pathway in Japan.