Reyderman, Larisa

Abstract The Tau Global Conference 2025, hosted by the Alzheimer's Association, CurePSP, and the Rainwater Charitable Foundation, convened international experts from academia, industry, government, and philanthropy to explore advances and challenges in tauopathy research. The meeting highlighted progress across tau biology, including emerging models of tau regulation, degradation, and propagation; advances in biomarker development for the diagnosis and staging of tauopathies; and evolving therapeutic strategies targeting diverse aspects of tau pathophysiology. Discussions also emphasized the importance of cross‐sector collaboration, and global initiatives to address disparities in tau research. This report synthesizes key insights from the conference and underscores the critical role of interdisciplinary, biomarker‐driven, and globally inclusive approaches in accelerating the translation of tau research into effective clinical applications.

Abstract As Alzheimer's disease (AD) research advances, tau has emerged as both a critical biomarker and a promising therapeutic target, central to understanding disease mechanisms, tracking progression, and guiding treatment development. The Fall 2024 Alzheimer's Association Research Roundtable convened experts from academia, industry, National Institutes of Health (NIH), and the United States Food and Drug Administration (FDA) to explore current progress and future directions in tau‐centered diagnostics and therapeutics. Discussions addressed the integration of tau biomarkers into the 2024 Revised Diagnostic Criteria for AD, updates to amyloid and tau positron emission tomography (PET) imaging, and modeling of biomarker trajectories. Presenters highlighted tau‐targeting therapeutics including antisense oligonucleotides, monoclonal antibodies, and small molecules, alongside innovations in drug delivery. The interplay between anti‐amyloid and anti‐tau therapies and strategic design of combination trials were key themes. Regulatory insights facilitated discussions on drug approval pathways. The meeting highlighted the rapid evolution of tau research and emphasized opportunities to improve diagnostics, trial design, and treatment strategies in AD. Highlights The Alzheimer's Association Research Roundtable (AARR) convened leaders from industry, academia, and government, to explore current progress and future directions in tau‐centered diagnostics and therapeutics. Tau has emerged as both a critical biomarker and a promising therapeutic target, central to understanding disease mechanisms, tracking progression, and guiding treatment development. Discussions addressed the integration of tau biomarkers into the 2024 revised diagnostic criteria for AD, updates to amyloid and tau PET imaging, modeling of biomarker trajectories, tau‐targeting therapeutics, and interplay between anti‐amyloid and anti‐tau therapies and strategic design of combination trials.

Abstract The Alzheimer's disease (AD) scientific field continues to make significant advances in early detection and treatments, which importantly rest on advances in our fundamental understanding of AD pathobiology and its contribution to cognitive decline. Clinical readouts of monoclonal antibodies against various forms of the amyloid beta (Aβ) protein indicate that the impact of these treatments may extend beyond reduction in amyloid plaques. The Alzheimer's Association Research Roundtable meeting held on May 17 and 18, 2022, reviewed our understanding to date of the impact of treatments targeting various species of Aβ; its impact on other related pathophysiology including tau; and ultimately, its effects on neurodegeneration and clinical decline, driven by the latest available data. Participants discussed the current evidence for a causal relationship among amyloid accumulation, tau alteration, and cognitive decline; the effect of anti‐amyloid therapies on clinical and biomarker endpoints; and how we can accelerate the pathway to therapeutic approval and what should guide us for the near future. Highlights The Alzheimer's Association Research Roundtable convened leaders from industry and academia, as well as patients, clinicians, and government and regulatory agency scientists to discuss the topic “Current Understanding of AD Pathophysiology & Impact of Amyloid‐beta Targeted Treatments on Biomarkers and Clinical Endpoints.” The totality of scientific evidence (clinical trials, animal data, modeling, and observational studies) on the relationship between amyloid beta (Aβ), amyloid, tau, and cognitive impairment is helping our understanding of the downstream effects and overall importance of lowering amyloid plaque load. Based on data from multiple phase 2 and 3 clinical trials of anti‐amyloid monoclonal antibodies, there is strong evidence to support that a sufficiently large reduction in amyloid plaque load to near‐normal levels is associated with positive changes in tau biomarkers and clinical endpoints. Reduction of Aβ plaque, measured easily by plasma amyloid biomarkers, is reasonably likely to predict benefit in clinical outcome measures.

ObjectiveIdentifying cerebrospinal fluid measures of the microtubule binding region of tau (MTBR‐tau) species that reflect tau aggregation could provide fluid biomarkers that track Alzheimer's disease related neurofibrillary tau pathological changes. We examined the cerebrospinal fluid (CSF) MTBR‐tau species in dominantly inherited Alzheimer's disease (DIAD) mutation carriers to assess the association with Alzheimer's disease (AD) biomarkers and clinical symptoms.MethodsCross‐sectional and longitudinal CSF from 229 DIAD mutation carriers and 130 mutation non‐carriers had sequential characterization of N‐terminal/mid‐domain phosphorylated tau (p‐tau) followed by MTBR‐tau species and tau positron emission tomography (tau PET), other soluble tau and amyloid biomarkers, comprehensive clinical and cognitive assessments, and brain magnetic resonance imaging of atrophy.ResultsCSF MTBR‐tau species located within the putative “border” region and one species corresponding to the “core” region of aggregates in neurofibrillary tangles (NFTs) increased during the presymptomatic stage and decreased during the symptomatic stage. The “border” MTBR‐tau species were associated with amyloid pathology and CSF p‐tau; whereas the “core” MTBR‐tau species were associated stronger with tau PET and CSF measures of neurodegeneration. The ratio of the border to the core species provided a continuous measure of increasing amounts that tracked clinical progression and NFTs.InterpretationChanges in CSF soluble MTBR‐tau species preceded the onset of dementia, tau tangle increase, and atrophy in DIAD. The ratio of 4R‐specific MTBR‐tau (border) to the NFT (core) MTBR‐tau species corresponds to the pathology of NFTs in DIAD and change with disease progression. The dynamics between different MTBR‐tau species in the CSF may serve as a marker of tau‐related disease progression and target engagement of anti‐tau therapeutics. ANN NEUROL 2023;93:1158–1172

Abstract Background Eribulin mesylate is a novel anticancer agent that inhibits microtubule growth, without effects on shortening, and promotes nonproductive tubulin aggregate formation. We performed a phase 1 trial to determine the dose‐limiting toxicities (DLTs), maximum tolerated or recommended phase 2 dose (MTD/RP2D), and pharmacokinetics (PK) of eribulin in children with refractory or recurrent solid (excluding central nervous system) tumors. Methods Eribulin was administered intravenously on days 1 and 8 in 21‐day cycles. Three dose levels (1.1, 1.4, and 1.8 mg/m 2 /dose) were evaluated using the rolling six design with additional patients enrolled into a PK expansion cohort at the MTD. PK samples were obtained following the day 1, cycle 1 dose. Results Twenty‐three patients, ages 3–17 (median 14) years were enrolled; 20 were evaluable for toxicity. DLTs occurred in 0/6 and 1/6 subjects at the 1.1 and 1.4 mg/m 2 /dose, respectively. One subject at the 1.4 mg/m 2 /dose had grade 4 neutropenia and grade 3 fatigue. At the 1.8 mg/m 2 /dose, 2/5 subjects experienced dose‐limiting (grade 4) neutropenia. Grade 3/4 non‐DLTs included lymphopenia and hypokalemia, while low‐grade toxicities included anorexia and nausea. No episodes of grade > 2 corrected QT interval prolongation or peripheral neuropathy were reported. Eribulin pharmacokinetic parameters were highly variable; the median elimination half‐life was 39.6 (range 24.2–96.4) hr. A partial response was observed in one patient (Ewing sarcoma). Conclusions Eribulin was well tolerated in children with refractory or recurrent solid tumors with neutropenia identified as the primary DLT. The RP2D of eribulin is 1.4 mg/m 2 /dose on days 1 and 8 of a 21‐day cycle.