New research from Eisai showed measurable correlations between amyloid biomarkers in the bloodstream and changes in the cerebrospinal fluid, bringing the company a step closer to developing a quick and simple blood test for Alzheimer’s disease.
The automated immunoassay system, being developed with the Kobe, Japan-based Sysmex for its HISCL line of analyzers, aims to deliver results in under 20 minutes using microliters of blood.
The protein test quantifies the ratio between amyloid beta peptide chains of different lengths—in this case, the prevalence of chains with 42 amino acids, compared to those with 40. Both chains can clump up to form the toxic plaques that injure nerve cells within the brain.
The latter, known as amyloid beta 1-40, is more common, and its levels in CSF do not significantly change with the progression of Alzheimer’s disease, according to Eisai—however, reductions in amyloid beta 1-42 are seen in the disorder’s early stages.
To look for a similar link in the blood, the companies took both plasma and CSF from healthy elderly patients and those with mild cognitive impairment. A strong correlation was found between the ratios seen in both samples. Eisai and Sysmex exhibited the results in a poster presentation at the Alzheimer's Association International Conference in Los Angeles.
As a next step, the companies plan to further assess the immunoassay’s clinical utility by checking for correlations between blood-based amyloid beta ratios and PET scans.
Earlier this month, Eisai opened its new center in Cambridge, Massachusetts, to explore the genetic relationships between various dementias and potential immunotherapies, as the Japanese pharma looks to move its Alzheimer’s disease pipeline away from amyloid beta and tau—at least as a target for therapeutic drugs—following clinical trial failures.
Instead, the center will pursue a new class of “immunodementia” drugs, employing genomics research, data science and precision chemistry, as well as the company’s first startup incubator.