The US Food and Drug Administration (FDA) has granted breakthrough device designation to Roche’s Elecsys pTau217 plasma biomarker assay.

The pTau217 assay was developed in collaboration with Eli Lilly and can be used to help identify the presence or absence of amyloid pathology in individuals. A positive result signifies a high likelihood of having a positive amyloid positron emission tomography (PET) / cerebrospinal fluid (CSF) result. Therefore, the test is intended to be used to help identify amyloid pathology, a feature of Alzheimer’s disease.

The use of tau levels to determine patient treatment for Alzheimer's has been a much-debated topic in recent months. Eli Lilly used tau levels as an inclusion criterion for the registrational Phase III trial (NCT04437511) for its monoclonal antibody, donanemab. The study reported having slowed disease progression by 35% on the integrated Alzheimer’s Disease Rating Scale (iADRS) compared to placebo. Furthermore, donanemab slowed disease progression in patients with high levels of tau by 29%.

While a PET/CSF result is needed to make the final positive amyloid result, the pTau217 assay could potentially serve as a screening test, if approved, for Alzheimer's patients. The pTau217 assay allows for the quantitative determination of the Phospho-Tau (pTau217) protein in the plasma of individuals aged 60 years and older. It also potentially serves as a diagnostic for Alzheimer’s, as it can distinguish the disease from other neurodegenerative disorders, at least in research settings.

Roche also has FDA-cleared Alzheimer’s pathology biomarker assays, namely the Elecsys beta-Amyloid (1-42) CSF II (Abeta42) and Elecsys Total-Tau CSF (tTau) assays, as part of its Elecsys portfolio. These are designed to be used as tTau/Abeta42 ratio to help inform Alzheimer’s diagnosis. Roche Elecsys’s portfolio also includes a neurofilament light chain (NfL) test for diagnosing multiple sclerosis test, interleukin 6 (IL-6) immunoassay for diagnosing neonatal sepsis, Elecsys HBeAg quant for diagnosing and monitoring hepatitis B, and Anti-HEV IgM and Elecsys Anti-HEV IgG immunoassays for detecting hepatitis E virus (HEV) infections.