LATE dementia

The Protein: Caused by misfolded TDP-43 protein (not amyloid or tau).
The Patient: Primarily affects the &#8220;oldest old&#8221; (age 80–85+ ).
The Symptoms: Mimics Alzheimer’s almost perfectly (memory loss, confusion), but progresses more slowly.
The Trap: Because it looks like Alzheimer&#8217;s, patients are often misdiagnosed. However, anti-amyloid drugs (like Leqembi) do not work because there is no amyloid to target.

The Diagnostic Pivot: For patients over 80, a negative amyloid scan is now a high-value finding. It rules out Alzheimer’s and points to LATE, saving the patient from expensive, risky, and ineffective treatments.

The “Double Hit”: Up to 50% of Alzheimer’s patients over 80 also have LATE (“Mixed Dementia”). Treating only the Alzheimer’s part (amyloid) often yields disappointing results because the LATE part (TDP-43) continues to damage the brain unchecked.

2026 Outlook: The industry is currently racing to validate a TDP-43 PET Tracer (specifically AC Immune’s ACI-19626), which would finally allow doctors to “see” this disease in a living patient rather than waiting for an autopsy.

LATE (Limbic-predominant Age-related TDP-43 Encephalopathy)

Thynkr Focus: Why this changes the game