C2N launches tau-tallying Alzheimer's blood test to join its amyloid-based screening tool

After proving that its blood test to measure the level of amyloid plaques in the brain matches up to the results of PET scans in predicting the onset of Alzheimer’s disease, C2N Diagnostics is expanding its slate of Alzheimer’s screening tools.

The newest development is another blood test, this one to count four different forms of tau in the brain. Excess amounts of the protein, like amyloid plaque, have been linked to the onset of Alzheimer’s, though clinical attempts to reduce buildups of either substance have yet to be proven to actually slow or stop the progression of the disease.

Like its amyloid-focused predecessor, the new test relies on mass spectrometry technology to analyze a small sample of blood. But while the former Fierce 15 honoree’s first test, PrecivityAD, is available via prescription in every state except New York, the tau-tallying assay is so far indicated for research use only.

With its research-use-only status, the test can be used by clinical researchers not only to improve their understanding of the link between tau buildups and the disease—and how it changes over time—but also to screen potential participants for clinical trials.

The new test quantifies both phosphorylated and nonphosphorylated forms of the tau217 and tau181 proteins. C2N said those four measurements could be a valuable addition to broader screening panels of biomarkers that could someday be used to help diagnose and track the progression of Alzheimer’s. Already, the company said, the test’s power is “uniquely amplified” when it’s used in tandem with the PrecivityAD screener.

“In the future, we expect that a combination of tests, including C2N’s, that each measure different aspects of Alzheimer’s biology will allow more healthcare providers to offer early Alzheimer’s diagnosis to patients with the aid of validated blood test results,” said Howard Fillit, M.D., co-founder and chief science officer of the Alzheimer’s Drug Discovery Foundation.

He continued, “This will also decrease the need for more invasive and expensive tests, such as cerebrospinal fluid tests and amyloid or tau PET imaging.”

Though C2N has yet to release clinical findings proving the test’s success in calculating tau, CEO Joel Braunstein, M.D., said in a statement that the data will be published in peer-reviewed journals and presented at “upcoming medical meetings.”

Last November, about a year after debuting the PrecivityAD test, C2N unveiled study results showing its ability to predict which patients experiencing symptoms of cognitive decline were at a heightened risk of developing Alzheimer’s.

The study compared the test’s amyloid probability scores matched up to the results of PET scans with 81% accuracy. The company said the findings prove PrecivityAD’s usefulness as a less expensive and simpler tool to aid in Alzheimer’s diagnosis and speed up clinical trial recruitment.