Tauklarify (florquinitau F-18 injection) is a brain PET tracer that identifies tau tangle pathology in adults with cognitive impairment being evaluated for Alzheimer's. The Alzheimer's Association explains in its updated appropriate-use guidance that amyloid PET detects plaques between neurons. Tau PET detects tangles inside neurons tied more closely to decline.
Lantheus announced in the FDA approval notice that the FDA approved Tauklarify on Aug. 14, 2026. Younger-onset families can now ask when tau PET adds useful staging or treatment-planning information beyond amyloid PET.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Official resources:
- Read the official notice from Lantheus — Use this primary source to verify the official announcement.
- Read the official guidance from Alz — Use this primary source to verify the official guidance.
Table of Contents
- What does each scan show?
- What did the 2026 approval add?
- When would a doctor use both scans?
- What are the limits of tau PET?
- What should younger-onset families ask?
What does each scan show?
Amyloid plaques build up between neurons and signal Alzheimer's biology. Tau tangles build up inside neurons and relate to cell injury. Both processes are linked to dementia.
Tau burden follows symptoms more closely than amyloid burden. A person can have amyloid buildup without major decline. More widespread tau often matches more active decline.
- Amyloid PET: shows plaques between neurons linked to Alzheimer's development.
- Tau PET: shows tangles inside neurons linked to dementia and decline.
What did the 2026 approval add?
NeurologyLive reported in its report on the approval studies that approval rested on two studies with more than 500 participants and five blinded readers. Positive agreement ranged from 68% to 88%. Negative agreement ranged from 93% to 99%.
Interreader agreement was high, with Fleiss kappa values of 0.92 and 0.86. In a within-participant comparison, MK-6240 discriminated Alzheimer's-related impairment better than Tauvid/flortaucipir, with AUC 0.93 versus 0.86. High agreement means different trained readers reached the same result more often. Better discrimination means fewer borderline calls in typical Alzheimer's evaluations.
When would a doctor use both scans?
Lantheus states tau PET complements amyloid PET and other tools. It gives a more complete picture rather than replacing amyloid testing. Amyloid answers whether Alzheimer biology is present. Clinicians told Being Patient in its reporting on clinician views that the new tracer may clarify complex or atypical diagnoses.
It may also help identify who might benefit most from anti-amyloid medications. Families can ask directly about staging and treatment planning. A useful question is whether tau location and extent change the working diagnosis. Another is whether tau results change medication choice, trial eligibility, or follow-up timing.
What are the limits of tau PET?
Lantheus states safety and effectiveness are not established for non-Alzheimer's tauopathies. A negative scan in suspected non-Alzheimer tau disease does not exclude tau pathology. The scan alone neither confirms nor excludes Alzheimer's. That limit matters when symptoms point away from typical Alzheimer's.
Movement changes, language loss, or strong behavioral shifts need separate workup. Families should ask what other tests still apply. A positive tau scan still needs clinical context. History, exam, cognitive testing, and amyloid status shape the final judgment. No single image decides the diagnosis.
What should younger-onset families ask?
Younger-onset means Alzheimer's affecting a person under 65. The person may still work or have children at home. Employment, childcare, and financial planning issues can be distinct.
Bring specific daily-life details to the visit. Work tasks, driving, supervision needs, and support at home all guide planning. Ask how scan timing affects leave, safety, and care decisions.
- Will tau PET clarify diagnosis, stage, or treatment choice in our case?
- How will results change medications, trials, counseling, or follow-up?
- What work, driving, childcare, and financial-planning steps should we take now?
- Bring a one-page work and childcare schedule plus current medication list to help the clinician judge next steps.
You Might Also Like
- How 2026 Tau Imaging News May Affect Alzheimer’s Workups: What Younger-Onset Alzheimer’s Families Should Know About the News
- PrecivityAD2 as an Adjunct to a 2026 Alzheimer’s Assessment: Accuracy, Limits, and Evidence Gaps for Younger-Onset Alzheimer’s Families
- FDA’s 2026 PrecivityAD2 Alzheimer’s Blood Test Clearance: Accuracy, Limits, and Evidence Gaps for Younger-Onset Alzheimer’s Families
