TAUKLARIFY: A New F-18 Tau PET Agent for Alzheimer’s Disease

What does tau PET show?

Alzheimer’s disease is associated with abnormal accumulation of amyloid-beta plaques and tau neurofibrillary tangles. Florquinitau F-18 binds to tau pathology, allowing its distribution to be visualised with PET.

Tau PET and amyloid PET answer different biological questions. A patient’s scan should therefore be interpreted within a wider diagnostic pathway rather than as a stand-alone yes-or-no test.

Who is the FDA-approved scan for?

The approved indication is for adults with cognitive impairment who are being evaluated for Alzheimer’s disease. The purpose is to identify patients with tau neurofibrillary tangle pathology.

This US approval should not be interpreted as confirmation of registration, routine availability or reimbursement in Malaysia. Local access must be checked with the relevant regulatory authorities and nuclear medicine service.

Evidence supporting approval

The approval was supported by two blinded image-reading studies using scans from more than 500 participants across three clinical trials. Participants included cognitively unimpaired individuals and people with mild cognitive impairment or mild Alzheimer’s disease dementia.

Reader agreement was high in both studies. However, performance may be lower earlier in the pathological spectrum, which is why scan findings must be integrated with other clinical evidence.

Important interpretation limits

• A negative scan does not necessarily exclude tau neurofibrillary tangle pathology.
• A positive scan does not necessarily confirm Alzheimer’s disease on its own.
• Effectiveness has not been established for non-Alzheimer’s disease tauopathies.
• Additional evaluation is appropriate whenever clinical uncertainty remains.

Administration, safety and preparation

The development studies used an approximate intravenous activity of 185 MBq (5 mCi). The exact protocol, acquisition and interpretation must follow the approved product information and the imaging centre’s procedures.

TAUKLARIFY involves ionising radiation. Patients are advised to hydrate before and after administration and to void frequently. The product information also advises avoiding CYP1A2 inducers, including tobacco smoking, for at least seven days before administration, and temporarily interrupting breastfeeding for a minimum of four hours afterward. Individual instructions must come from the treating team.

• Commonly reported adverse reactions were headache, nausea, injection-site reactions, dizziness and abdominal discomfort.
• Pregnancy, breastfeeding, medicines and smoking status should be discussed with the nuclear medicine team before the appointment.

Where this fits in nuclear medicine

TAUKLARIFY illustrates the shift from general metabolic imaging toward molecular imaging of specific disease biology. For Alzheimer’s disease, tau PET may provide information that complements amyloid PET rather than replacing it.

For a broader introduction to molecular imaging, see the PET/CT patient guide.