A critical appraisal of tau-targeting therapies for primary and secondary tauopathies

Introduction: Primary tauopathies are neurological disorders in which Tau Protein deposition is the predominant pathological feature. Alzheimer's disease is a secondary tauopathy with tau forming hyperphosphorylated insoluble aggregates. Tau pathology can propagate from region to region in the brain, while alterations in tau processing may impair tau physiological functions.

Methods: We reviewed literature on tau biology and anti-tau drugs using PubMed, meeting abstracts, and ClnicalTrials.gov.

Results: The past 15 years have seen >30 drugs interfering with tau aggregation, processing, and accumulation reaching the clinic. Initial results with tau aggregation inhibitors and anti-tau monoclonal Antibodies have not shown clinical efficacy.

Discussion: The reasons for these clinical failures are unclear but could be linked to the clearing of physiological forms of tau by non-specific drugs. Research is now concentrating efforts on developing reliable translational animal models and selective compounds targeting specific tau epitopes, neurotoxic tau aggregates, and post-translational tau modifications.

Alzheimer's disease; N-truncated-tau; amyloid beta; corticobasal degeneration; frontotemporal dementia; frontotemporal lobar degeneration; oligomeric tau; p-tau-181; p-tau-205; p-tau-217; p-tau-231; phosphorylated tau; primary tauopathies; progressive supranuclear palsy; tau.