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AbstractINTRODUCTIONHigher male prevalence in sporadic behavioral variant frontotemporal dementia (bvFTD) has been reported. We hypothesized differences in phenotypes between genetic and sporadic bvFTD females resulting in underdiagnosis of sporadic bvFTD females.METHODSWe included genetic and sporadic bvFTD patients from two multicenter cohorts. We compared behavioral and cognitive symptoms, and gray matter volumes, between genetic and sporadic cases in each sex.RESULTSFemales with sporadic bvFTD showed worse compulsive behavior (p = 0.026) and language impairments (p = 0.024) compared to females with genetic bvFTD (n = 152). Genetic bvFTD females had smaller gray matter volumes than sporadic bvFTD females, particularly in the parietal lobe.DISCUSSIONFemales with sporadic bvFTD exhibit a distinct clinical phenotype compared to females with genetic bvFTD. This difference may explain the discrepancy in prevalence between genetic and sporadic cases, as some females without genetic mutations may be misdiagnosed due to atypical bvFTD symptom presentation.Highlights Sex ratio is equal in genetic behavioral variant of frontotemporal dementia (bvFTD), whereas more males are present in sporadic bvFTD. Distinct neuropsychiatric phenotypes exist between sporadic and genetic bvFTD in females. Phenotype might explain the sex ratio difference between sporadic and genetic cases.

ImportanceMyeloperoxidase is one of the most abundant peroxidase enzymes in activated myeloid cells. Myeloperoxidase inhibitors may have a clinical benefit in amyotrophic lateral sclerosis (ALS) by slowing neurodegeneration via reduced neuroinflammation and oxidative stress.ObjectiveTo determine the safety, tolerability, and efficacy of verdiperstat, a selective myeloperoxidase inhibitor, in ALS.Design, Settings, and ParticipantsVerdiperstat was tested as a regimen of the HEALEY ALS Platform Trial, a multicenter, double-blind, perpetual platform design, randomized clinical trial, with sharing of trial infrastructure and placebo data across multiple regimens. The study was conducted at 54 ALS referral centers across the US from July 2020 to April 2022. Adult participants with a diagnosis of clinically possible, probable, laboratory-supported probable, or definite ALS defined by the revised El Escorial criteria were randomized to verdiperstat or regimen-specific placebo. An additional group of participants concurrently randomized to placebo from other regimens was included in the analyses.InterventionsEligible participants were randomized in a 3:1 ratio to receive oral verdiperstat, 600 mg, twice daily or matching placebo for a planned placebo-controlled duration of 24 weeks.Main Outcomes and MeasuresThe primary efficacy outcome was change from baseline through week 24 in disease severity, as measured by a joint model of ALS Functional Rating Scale–Revised and survival, with the treatment effect quantified by the disease rate ratio (DRR), with DRR less than 1 indicating a slowing in disease progression of verdiperstat relative to placebo.ResultsA total of 167 participants (mean [SD] age, 58.5 [11.4] years; 59 [35.3%] female; 108 [64.6%] male) were randomized to either verdiperstat (126 [75.4%]) or to placebo (41 [25.6%]). Among the participants randomized to the verdiperstat regimen, 130 (78%) completed the trial. The estimated DRR was 0.98 (95% credible interval, 0.77-1.24; posterior probability = 0.57 for slowing of disease progression [DRR <1]). Verdiperstat was estimated to slow progression by 2% vs placebo (95% credible interval, −23% to 24%; posterior probability 0.57). Verdiperstat was overall safe and well tolerated. Common adverse events in the verdiperstat group were nausea, insomnia, and elevated thyrotropin levels.Conclusions and RelevanceResults demonstrate that treatment with verdiperstat was unlikely to alter disease progression in ALS.Trial RegistrationClinical Trial Identifiers: NCT04297683 and NCT04436510

ImportanceAmyotrophic lateral sclerosis (ALS) is a fatal disease. The sigma-1 (σ1) receptor emerged as a target for intervention.ObjectiveTo determine the effects of pridopidine, a σ1-receptor agonist, in ALS.Design, Settings, and ParticipantsPridopidine was tested as a regimen of the HEALEY ALS Platform Trial, a phase 2/3, multicenter, randomized, double-blind, platform trial. The study was conducted at 54 sites in the US from January 2021 to July 2022 (final follow-up, July 14, 2022). A total of 163 participants with ALS were randomized to receive pridopidine or placebo. An additional 122 concurrently randomized participants were assigned to receive placebo in other regimens and included in the analyses.InterventionsEligible participants were randomized 3:1 to receive oral pridopidine 45 mg twice daily (n = 121) or matching oral placebo (n = 42) for a planned duration of 24 weeks.Main Outcomes and MeasuresThe primary efficacy outcome was change from baseline through week 24 in ALS disease severity, analyzed using a bayesian shared parameter model, which has components for function (Revised Amyotrophic Lateral Sclerosis Functional Rating Scale [ALSFRS-R]) and survival that were linked through an integrated estimate of treatment-dependent disease slowing across these 2 components. This was denoted as the disease rate ratio (DRR), with DRR less than 1 indicating a slowing in disease progression on pridopidine relative to placebo. There were 5 key secondary end points: time to 2-point or greater reduction in ALSFRS-R total score among participants with bulbar dysfunction at baseline, rate of decline in slow vital capacity among participants with bulbar dysfunction at baseline, percentage of participants with no worsening in the ALSFRS-R bulbar domain score, time to 1-point or greater change in the ALSFRS-R bulbar domain score, and time to death or permanent assisted ventilation.ResultsAmong 162 patients (mean age, 57.5 years; 35% female) who were randomized to receive the pridopidine regimen and included in the primary efficacy analysis, 136 (84%) completed the trial. In the primary analysis comparing pridopidine vs the combined placebo groups, there was no significant difference between pridopidine and placebo in the primary end point (DRR, 0.99 [95% credible interval, 0.80-1.21]; probability of DRR <1, 0.55) and no differences were seen in the components of ALSFRS-R or survival. There was no benefit of pridopidine on the secondary end points. In the safety dataset (pridopidine, n = 121; placebo, n = 163), the most common adverse events were falls (28.1% vs 29.3%, respectively) and muscular weakness (24.0% vs 31.7%, respectively).Conclusions and RelevanceIn this 24-week study, pridopidine did not impact the progression of ALS.Trial RegistrationClinicalTrials.gov Identifiers: NCT04297683, NCT04615923

Importance The etiology of amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease, is unknown. However, neuroinflammation and complement activation may play a role in disease progression. Objective To determine the effects of zilucoplan, an inhibitor of complement C5, in individuals with ALS. Design, Setting, and Participants Zilucoplan was tested as regimen A of the HEALEY ALS Platform Trial, a phase 2 to 3 multicenter, randomized, double-blind, placebo-controlled perpetual platform clinical trial with sharing of trial infrastructure and placebo data across multiple regimens. Regimen A was conducted from August 17, 2020, to May 4, 2022. A total of 162 participants were randomized to receive zilucoplan (122 [75.3%]) or regimen-specific placebo (40 [24.7%]). An additional 124 concurrently randomized participants were randomized to receive placebo in other regimens. Interventions Eligible participants were randomized in a 3:1 ratio to receive zilucoplan or matching placebo within strata of edaravone and/or riluzole use for a planned duration of 24 weeks. Active drug (zilucoplan, 0.3 mg/kg) and placebo were provided for daily subcutaneous dosing. Main Outcomes and Measures The primary end point was change in disease severity from baseline through 24 weeks as measured by the Amyotrophic Lateral Sclerosis Functional Rating Scale–Revised (ALSFRS-R) total score and survival, analyzed using a bayesian shared-parameter model and reported as disease rate ratio (DRR; <1 indicating treatment benefit). The study included prespecified rules for early stopping for futility. Outcome analyses were performed in the full analysis set comparing the zilucoplan group with the total shared placebo group (n = 164). Results Among the 162 participants who were randomized (mean [SD] age, 59.6 [11.3]; 99 [61.1%] male), 115 (71.0%) completed the trial. The estimated DRR common to ALSFRS-R and survival was 1.08 (95% credible interval, 0.87-1.31; posterior probability of superiority, 0.24). The trial was stopped early for futility. No unexpected treatment-related risks were identified. Conclusions and Relevance In this randomized clinical trial of zilucoplan in ALS, treatment did not alter disease progression. The adaptive platform design of the HEALEY ALS Platform Trial made it possible to test a new investigational product with efficient use of time and resources. Trial Registration ClinicalTrials.gov Identifier: NCT04297683

Importance Bioenergetic failure has been proposed as a driver of amyotrophic lateral sclerosis (ALS). CNM-Au8 is a suspension of gold nanocrystals that catalyzes the conversion of nicotinamide adenine dinucleotide hydride into NAD + , resulting in an increase of cellular adenosine triphosphate production. Objective To determine the effects of CNM-Au8 on ALS disease progression. Design, Setting, and Participants CNM-Au8 was tested as a regimen of the HEALEY ALS Platform Trial, a phase 2/3, multicenter, randomized, double-blind platform trial. The study was conducted at 54 sites in the US from July 2020 to March 2022 (final follow-up, March 17, 2022). A total of 161 participants with ALS were randomized to receive CNM-Au8 (n = 120) or regimen-specific placebo (n = 41). Data from 123 concurrently randomized placebo participants in other regimens were combined for analyses. Interventions Eligible participants were randomized in a 3:3:2 ratio to receive CNM-Au8 60 mg daily (n = 61), CNM-Au8 30 mg daily (n = 59), or matching placebo (n = 41) for 24 weeks. Main Outcomes and Measures The primary efficacy outcome was change from baseline through week 24 in ALS disease severity measured by a bayesian shared parameter model of function (based on the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale) and survival, which provided an estimate of the rate of disease progression measured by the disease rate ratio (DRR), with a DRR of less than 1 indicating treatment benefit. Secondary end points included a Combined Assessment of Function and Survival using a joint-rank test, rate of decline in slow vital capacity (percent predicted), and survival free of permanent assisted ventilation. Results Among 161 participants who were randomized within the CNM-Au8 regimen (mean age, 58.4 years; 61 [37.9%] female), 145 (90%) completed the trial. In the primary analysis comparing the combined CNM-Au8 dosage groups vs the combined placebo groups, the primary end point (DRR, 0.97 [95% credible interval, 0.783-1.175]; posterior probability of DRR <1, 0.65) and the 3 secondary end points suggested no benefit or harm of CNM-Au8. In the active (n = 120) vs placebo (n = 163) groups, the most common adverse events were diarrhea (23 [19%] vs 12 [7%]), nausea (17 [14.2%] vs 14 [8.6%]), fatigue (12 [10.8%] vs 30 [18.4%]), and muscular weakness (24 [20%] vs 45 [27.6%]). Conclusions and Relevance No benefit of CNM-Au8 on ALS disease progression was observed at 24 weeks. Trial Registration ClinicalTrials.gov Identifiers: NCT04297683 , NCT04414345

Abstract Limbic predominant age‐related TDP‐43 encephalopathy neuropathologic change (LATE‐NC) is highly prevalent in late life and a common co‐pathology with Alzheimer's disease neuropathologic change (ADNC). LATE‐NC is a slowly progressive, amnestic clinical syndrome. Alternatively, when present with ADNC, LATE‐NC is associated with a more rapid course. With the emergence of anti‐amyloid therapeutics, discrimination of LATE‐NC from ADNC is critical and will lead to greater clinical recognition of amnestic patients without ADNC. Furthermore, co‐pathology with LATE‐NC may influence outcomes of these therapeutics. Thus there is a need to identify patients during life with likely LATE‐NC. We propose criteria for clinical diagnosis of LATE as an initial framework for further validation. In the context of progressive memory loss and substantial hippocampal atrophy, criteria are laid out for probable (amyloid negative) or possible LATE (amyloid biomarkers are unavailable or when amyloid is present, but hippocampal neurodegeneration is out of proportion to expected pure ADNC). Highlights Limbic‐predominant age‐related TDP‐43 encephalopathy (LATE) is a highly prevalent driver of neuropathologic memory loss in late life. LATE neuropathologic change (LATE‐NC) is a common co‐pathology with Alzheimer's disease neuropathologic change (ADNC) and may influence outcomes with emerging disease‐modifying medicines. We provide initial clinical criteria for diagnosing LATE during life either when LATE‐NC is the likely primary driver of symptoms or when observed in conjunction with AD. Definitions of possible and probable LATE are provided.

AbstractBackgroundAs new anti‐amyloid immunotherapies emerge for Alzheimer’s disease (AD), it is clear that early diagnosis of AD pathology is crucial for treatment success. This can be challenging in atypical presentations of AD and, together with our reliance on CSF or PET scans, can, at times, lead to delayed diagnosis. Here, we further explore the possible role of plasma tau phosphorylated at threonine 217 (P‐tau217) for the detection of primary AD or AD co‐pathology when frontotemporal dementia spectrum disorders are the main clinical presentation.MethodParticipants were recruited through ALLFTD, a North American multisite research consortium for the longitudinal assessment of frontotemporal lobar degeneration. After excluding cases with known FTD‐causing mutations, 573 participants with sporadic disease, mild cognitive/behavioral impairment, or healthy familial controls evaluated between 2014 and 2023 were included in this analysis (45.8% female, median age 66 years). 39 of those cases underwent neuropathological evaluation. Plasma P‐tau217 was measured with the Eli Lilly electrochemiluminescence‐based assay. P‐tau217 concentrations were compared by phenotype, disease severity, genotype, and, when available, neuropathological diagnosis with non‐parametric tests. Its diagnostic performance was tested with ROC curves. Associations between plasma P‐tau217 concentrations and clinical scales of global cognition, memory, executive function, motor function, and social cognition with linear regressions and non‐parametric tests.ResultPlasma P‐tau217 concentrations were higher in logopenic variant primary progressive aphasia (lvPPA) and amnestic dementia (AmDem), compared to participants with normal cognition or other FTD phenotypes. P‐tau217 concentrations were higher in APOE e4 carriers, compared to non‐carriers, regardless of phenotype, but were not affected by disease severity. P‐tau217 concentrations showed associations with clinical measures of global cognition, memory, and executive function, but had no associations with measures of motor function or social cognition. Plasma P‐tau217 concentrations were elevated in high and intermediate ADNC scoring, or more advanced Braak stages, even when AD was not the primary pathology.ConclusionEven when FTD is suspected, high plasma p‐tau 217 concentrations are strongly associated with underlying AD as primary pathology or contributing co‐pathology. Plasma P‐tau217 could be a tool to support the development of disease‐modifying therapies for atypical Alzheimer’s disease presentations or for FTD cases with Alzheimer’s disease co‐pathology.

AbstractBackgroundThere is a strong link between tau and progression of Alzheimer’s disease (AD), necessitating an understanding of tau spreading mechanisms. Prior research, predominantly in typical AD, suggested that tau propagates from epicenters (regions with earliest tau) to functionally connected regions. However, given the constrained spatial heterogeneity of tau in typical AD, validating this connectivity‐based tau spreading model in AD variants with distinct tau deposition patterns is crucial.MethodWe included 269 amyloid‐β‐positive (PET/CSF) individuals with clinically diagnosed atypical AD (113 posterior cortical atrophy, PCA‐AD; 83 logopenic variant primary progressive aphasia, lvPPA‐AD; 33 behavioural variant AD, bvAD; 40 corticobasal syndrome, CBS‐AD) and 68 with typical AD from 12 international cohorts, who underwent tau‐PET (54% [18F]AV1451/[18F]flortaucipir/Tauvid, 27% [18F]MK6240, 19% [18F]PI2620). Using Gaussian mixture modeling including amyloid‐β‐negative controls, cross‐sectional tau‐PET standardized uptake value ratios within Schaefer‐200 atlas regions were transformed to tau positivity probabilities. Tau epicenters were defined as the 5% regions with highest tau positivity probabilities. For each variant, the association between functional connectivity‐based distance (using the 30% strongest positive region‐to‐region connections of a group‐average connectivity matrix from ADNI elderly controls) and tau‐PET covariance (group‐average correlation per region pair) was assessed through linear regression, adjusting for age, sex, site, and Euclidean distance. Regions were categorized based on functional proximity to the epicenter (quartiles 1‐4) and tau positivity probabilities were assessed accordingly.ResultTau positivity probabilities matched clinical variants, with a posterior pattern in PCA‐AD, left‐hemispheric dominant pattern in lvPPA‐AD, widespread pattern in bvAD, sensorimotor cortex involvement in CBS‐AD, and temporo‐parietal predominance in typical AD (Figure 1). In line with this, tau epicenters were highly heterogeneous across variants (Figure 1). In all variants, greater tau‐PET covariance was associated with shorter functional connectivity‐based distance (Figure 2). We observed that regions in closer functional proximity to the epicenter exhibited higher tau positivity probabilities than regions functionally further away (p<0.05, Figure 3).ConclusionThis multi‐center study shows that the brain’s functional architecture serves as a universal predictor of tau spreading in AD. Since tau is a key driver of neurodegeneration and cognitive decline in AD, this finding holds potential for personalized medicine and defining participant‐specific endpoints in clinical trials.