Tau PET-Guided Tau Immunotherapy is a precision medicine approach that uses tau positron emission tomography (PET) imaging as both a patient selection criterion and an efficacy readout for anti-tau immunotherapies in Alzheimer's disease and primary tauopathies.
Tau PET imaging with ligands like [^18F]Flortaucipir (AV-1451) allows in vivo visualization of tau pathology burden, enabling personalized dosing and treatment selection.
- Passive immunization - Anti-tau monoclonal antibodies
- Active vaccination - Tau片段疫苗 to generate anti-tau antibodies
- Antibody-mediated clearance - Fc receptor-mediated microglial phagocytosis
| Biomarker |
Target |
Measurement Method |
Expected Change |
| Tau PET (global) |
SUVR reduction |
[^18F]Flortaucipir PET |
20-40% reduction |
| Tau PET (regional) |
Braak stage reduction |
Regional SUVR |
Staging regression |
| CSF total tau |
Decrease |
ELISA |
30-50% reduction |
| CSF p-tau181 |
Decrease |
Simoa |
30-50% reduction |
| CSF p-tau217 |
Decrease |
Simoa |
40-60% reduction |
- Positive amyloid PET (A+)
- Elevated tau PET (Braak I-IV)
- Clinical diagnosis of AD or MCI due to AD
- No contraindications to PET imaging
¶ Therapeutic Candidates
- Semorinemab - Anti-tau antibody (Roche/Genentech)
- Gantenerumab - Anti-Aβ/tau antibody
- Lecanemab - Anti-Aβ protofibril antibody
- Tilavonemab - Anti-tau antibody (AbbVie)
- JNJ-63733657 - Anti-tau antibody (J&J)
- Tau aggregation inhibitors - Small molecules blocking tau aggregation
- O-GlcNAcase inhibitors - Reducing tau hyperphosphorylation
- Autophagy inducers - Enhancing tau clearance
- Screen with tau PET to identify tau-positive patients
- Quantify baseline tau burden (SUVR >1.3)
- Stratify by Braak stage
- Dose escalation based on tau PET response
- Early terminators if no reduction at 6 months
- Extended treatment for responders
- Primary: Change in tau PET SUVR at 18 months
- Secondary: Cognitive composites, CSF biomarkers, brain atrophy
| Timepoint |
Tau PET |
CSF p-tau |
Cognitive Test |
| Baseline |
Required |
Required |
Required |
| 6 months |
Optional |
Required |
Required |
| 12 months |
Required |
Required |
Required |
| 18 months |
Required |
Required |
Required |
- Tau PET sensitivity - Ligand binding to off-target regions
- Antibody brain penetration - Limited BBB crossing
- Treatment timing - Late-stage patients may not benefit
- Cost - PET imaging expensive
- Second-generation tau PET ligands with improved specificity
- Combination of anti-tau and anti-amyloid therapies
- Blood-based tau biomarkers (p-tau217, p-tau181) for monitoring