HEADER: FDA’s 2025 Alzheimer’s test approvals reveal a new split in strategy—Fujirebio’s plasma ratio test is indicated for centers for diagnosis, while Roche’s Tau181 test is limited to “rule-out” use, but in primary care.
###
There are some surprising nuances to recent Alzheimer test approvals at the FDA.
In May 2025, FDA approved the first-ever PLASMA test for Alzheimer's disease, a combined Tau217 and Amyloid42 test from Fujirebio. (Fujirebio previously had a CSF test for Alzheimer's.) The test has a double cut-off; below the lower cut, Alzheimer's is unlikely; above the higher cut, Alzheimer's is likely, and for a few patients in-between, the test is indeterminate.
Recall that the "intended use" is from the viewpoint of the physician, and "indicated use" is the patient condition or situation for use. The Lumipulse Plasma Ratio is "intended to aid healthcare providers to identify patients with amyloid pathology associated with Alzheimer's disease." The Plasma Ratio is "indicated for adult patients, age 50 and older, presenting at a specialized care center with signs and symptoms of cognitive decline." This FDA wording on the label foots to the title of the July 2025 guideline for Alzheimer blood testing, which also uses the phrase "in a specialized care center." (Palmquvist 2025).
Typically, a sign is objective (fever), a symptom is subjective (headache). See Fujirebio's detailed FDA summary here.
In contrast, we have a headline in Genomeweb, October 2025, "Roche Targets Primary Care Setting With Newly FDA-Cleared Alzheimer's Rule-Out Test." This plasma Tau181 test is only intended to "rule out" (which is driven by a one-sided low value), while the indicated setting is "primary care" rather than "a specialized care center."
The new October Genomeweb article on Roche tracks back to a May 2025 article on these debates in the field (here), and a JAMA IM op ed by Wider and Covinsky on settings for blood testing.
