The development of new biomarkers to supplement our current clinical measures of function will therefore be critical to enable measurement of target engagement, help evaluate other pharmacodynamic effects, and measure disease progression. For amyloid-targeted AD therapies, pharmacodynamic biomarkers such as amyloid PET imaging have helped identify whether therapies that engage the target have clear pharmacodynamic effects that correlate with clinical status. [127] Improved tau biomarkers would allow smaller, shorter trials, and basket designs, such as in the TauBasket and TPI 257 trial which allowed unbiased evaluation in diverse tauopathies. Much of the focus is appropriately on Alzheimer’s disease as the most prevalent tauopathy, but observing drug effect in other tauopathies, especially where tau is the sole neuropathologic etiology, may be more informative regarding tau’s role in these disparate diseases.
