Roche secured FDA clearance for a set of diagnostic assays that capture two of the main biomarkers for Alzheimer’s disease, found in the body’s cerebrospinal fluid.
The company’s pair of Elecsys tests—used to determine the ratio between the hallmark proteins known as amyloid beta and tau—are designed to help screen adults age 55 and older who are being evaluated for the condition.
The use of a CSF protein test on a broader scale, according to Roche, could help shift the process of diagnosing Alzheimer’s from a set of tasks meant to exclude the possibility of the disease—such as repeated cognitive exams, lab work and CT or MRI scans—to one that aims to confirm it.
The company estimates that current clinical criteria may only lead to an accurate diagnosis 70% to 80% of the time. And while positron emission tomography, or PET scans, can be more conclusive by measuring amyloid beta plaques in the brain, their high cost and low availability can limit their use.
Roche pegged the accuracy of its Elecsys assays, which run on its cobas immunoassay system, to 90% concordance with amyloid PET imaging. Though gathering CSF samples would still require a complicated spinal tap procedure, they can be cheaper than PET scans and would not come with exposure to radiation.
“Globally, up to 75% of people living with Alzheimer’s disease have not been diagnosed, and those who have, often report a long and complicated process,” Roche Diagnostics CEO Thomas Schinecker said in a release. “As we are starting to see exciting results for new potential Alzheimer’s treatments, reliable tests that have been clinically validated will be critical in ensuring the right patients are identified and able to benefit from them.”
Those drugs include lecanemab, an anti-amyloid antibody being developed by Eisai and Biogen that earlier this year hit the primary and secondary endpoint of a phase 3 randomized trial involving 1,795 people with early Alzheimer’s. After a year-and-a-half, lecanemab slowed the rate of cognitive decline by 27% versus placebo.
However, lecanemab’s clinical journey has also come with recent reports of patient deaths due to brain hemorrhages. Eisai and Biogen presented their full report on the trial at the Clinical Trials on Alzheimer’s Disease conference in late November.
Roche, meanwhile, has seen its own setbacks in developing an Alzheimer’s treatment. Its gantenerumab antibody, which also targets amyloid beta proteins, failed to make it through two phase 3 trials previously this year. By early December, Roche’s Genentech unit said it would cut multiple gantenerumab development programs after seeing insufficient clinical benefits.
On the diagnostic side, Roche received a breakthrough designation from the FDA this past summer for its blood-based amyloid test, currently under development.
With a simpler and less invasive option, collected blood samples could be used to help guide patients toward eventual confirmation of abnormal amyloid levels and a diagnosis of Alzhiemer’s by using the Elecsys CSF assays.