Bowser, Robert

Importance Tofersen is a disease-modifying antisense oligonucleotide therapeutic for people living with SOD1 –amyotrophic lateral sclerosis ( SOD1 -ALS). Autopsy tissue donors have provided the first opportunity to study the distribution of intrathecally administered tofersen in human central nervous system tissues. Objectives To determine the tissue distribution of tofersen and to provide the first estimates of SOD1 reduction in human somatic motor systems tissues. Design, Setting, and Participants This was a cross-sectional autopsy tissue case series conducted between 2018 and 2026. Autopsies were performed at 3 US academic medical institutions. Tissue samples from 8 deceased patients who lived with SOD1 -ALS, participated in tofersen clinical trials (ClinicalTrials.gov Identifiers NCT02623699 [An Efficacy, Safety, Tolerability, Pharmacokinetics and Pharmacodynamics Study of BIIB067 (Tofersen) in Adults With Inherited Amyotrophic Lateral Sclerosis (ALS)] and NCT03070119 [Long-Term Evaluation of BIIB067 (Tofersen)]) or the Expanded Access Program, and whose families authorized autopsies were eligible for this study. All autopsy tissue donors known at the time of this study were included (none were excluded). Analyses were conducted between August 2020 and January 2026. Exposures Participants received multiple intrathecal 20- to 100-mg tofersen doses. Main Outcomes and Measures Tofersen tissue concentrations were measured using hybridization enzyme-linked immunosorbent assay (ELISA). SOD1 messenger RNA (mRNA) and protein reduction estimates, defined as percentage SOD1 levels in this study’s recently treated autopsy tissue donors compared to a cohort of samples from tofersen-naive SOD1 -ALS autopsy tissue donors, were measured using quantitative reverse transcription polymerase chain reaction (PCR) and ELISA. Histological localization of tofersen and SOD1 transcripts were studied using immunohistochemistry and in situ hybridization assays. Results In 8 tofersen-treated autopsy tissue donors (5 male and 3 female donors; age range, 42-66 years), spinal cord and motor cortical tissue tofersen concentrations strongly correlated with predictions based on individual dosing histories and a preclinical pharmacokinetic model. For 3 recently treated autopsy tissue donors, reductions in lumbar spinal cord tissue SOD1 mRNA and protein levels ranged from 45% to 84% despite not having been administered 1 to 2 scheduled doses before autopsy. Residual somatic motor neurons demonstrated tofersen transduction and low SOD1 mRNA probe hybridization. Misfolded SOD1 protein inclusions were detected in residual motor neurons of tofersen-naive SOD1- ALS tissue donor controls and tofersen-treated tissue donors. Meningeal and perivascular lymphocytic immune responses were observed in 5 recently treated tissue donors but were not apparent in tissue donors with remote final tofersen doses. Conclusions and Relevance This case series presents the first emerging autopsy tissue data confirming the predicted distribution of tofersen and robust SOD1 protein reduction in human somatic motor systems tissues.

Abstract Amyotrophic lateral sclerosis (ALS) is a fatal, rapidly progressive neurodegenerative disease of motor neurons for which therapeutics are limited. Improved biomarkers are imperative to improve patient care and therapeutic development. Here, we employed 35-plex isobaric tandem mass tag labeling based on isobutyl-proline reporter group (TMTpro) to perform unbiased proteomic analysis of cerebrospinal fluid (CSF) and plasma from control (n= 28, n= 31) and sporadic ALS (sALS) (n= 39, n= 41), from the Target ALS Global Natural History Study (TALS GNHS). We identified 2,875 proteins in CSF and 1,118 proteins in plasma and identified known and novel differentially expressed proteins (DEPs) between controls and sALS, some of which were orthogonally validated using immunoassay. Comparison of TMTpro-MS and Olink proximity extension assay proteomics revealed common and non-overlapping differentially expressed proteins illustrating strengths unique to each platform. This initial cross-sectional proteomic study of biofluids from the TALS GNHS, with unrestricted availability of study results to the research community, highlights the potential of this resource as a potent platform for ALS biomarker discovery.

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 Introduction/Aims Biomarkers have shown promise in amyotrophic lateral sclerosis (ALS) research, but the quest for reliable biomarkers remains active. This study evaluates the effect of debamestrocel on cerebrospinal fluid (CSF) biomarkers, an exploratory endpoint. Methods A total of 196 participants randomly received debamestrocel or placebo. Seven CSF samples were to be collected from all participants. Forty‐five biomarkers were analyzed in the overall study and by two subgroups characterized by the ALS Functional Rating Scale‐Revised (ALSFRS‐R). A prespecified model was employed to predict clinical outcomes leveraging biomarkers and disease characteristics. Causal inference was used to analyze relationships between neurofilament light chain (NfL) and ALSFRS‐R. Results We observed significant changes with debamestrocel in 64% of the biomarkers studied, spanning pathways implicated in ALS pathology (63% neuroinflammation, 50% neurodegeneration, and 89% neuroprotection). Biomarker changes with debamestrocel show biological activity in trial participants, including those with advanced ALS. CSF biomarkers were predictive of clinical outcomes in debamestrocel‐treated participants (baseline NfL, baseline latency‐associated peptide/transforming growth factor beta1 [LAP/TGFβ1], change galectin‐1, all p < .01), with baseline NfL and LAP/TGFβ1 remaining ( p < .05) when disease characteristics ( p < .005) were incorporated. Change from baseline to the last measurement showed debamestrocel‐driven reductions in NfL were associated with less decline in ALSFRS‐R. Debamestrocel significantly reduced NfL from baseline compared with placebo (11% vs. 1.6%, p = .037). Discussion Following debamestrocel treatment, many biomarkers showed increases (anti‐inflammatory/neuroprotective) or decreases (inflammatory/neurodegenerative) suggesting a possible treatment effect. Neuroinflammatory and neuroprotective biomarkers were predictive of clinical response, suggesting a potential multimodal mechanism of action. These results offer preliminary insights that need to be confirmed.

Abstract The choroid plexus (ChP) produces and is bathed in the cerebrospinal fluid (CSF), which in aging and Alzheimer's disease (AD) shows extensive proteomic alterations including evidence of inflammation. Considering inflammation hampers functions of the involved tissues, the CSF abnormalities reported in these conditions are suggestive of ChP injury. Indeed, several studies document ChP damage in aging and AD, which nevertheless remains to be systematically characterized. We here report that the changes elicited in the CSF by AD are consistent with a perturbed aging process and accompanied by aberrant accumulation of inflammatory signals and metabolically active proteins in the ChP. Magnetic resonance imaging (MRI) imaging shows that these molecular aberrancies correspond to significant remodeling of ChP in AD, which correlates with aging and cognitive decline. Collectively, our preliminary post‐mortem and in vivo findings reveal a repertoire of ChP pathologies indicative of its dysfunction and involvement in the pathogenesis of AD. Highlights Cerebrospinal fluid changes associated with aging are perturbed in Alzheimer's disease Paradoxically, in Alzheimer's disease, the choroid plexus exhibits increased cytokine levels without evidence of inflammatory activation or infiltrates In Alzheimer's disease, increased choroid plexus volumes correlate with age and cognitive performance

AbstractBackgroundTAR DNA‐binding protein 43 (TDP‐43) mislocalization is present in over 50% of patients with frontotemporal dementia and about 20% of patients with Alzheimer’s disease, but there is still an unmet need for clinical trials targeting sporadic TDP‐43 pathology in patients with dementia. The semantic variant of primary progressive aphasia (svPPA) is highly predictive of frontotemporal lobar degeneration with TDP‐43 mislocalization (FTLD‐TDP) and presents an ideal cohort in which to explore therapeutics with potential benefit across the spectrum of TDP‐43 pathology. Oxidative stress promotes mislocalization of TDP‐43 in neurons and may be a viable therapeutic target in svPPA and other FTLD‐TDP disorders. Verdiperstat is a potent, oral, CNS penetrant, myeloperoxidase inhibitor that reduces production of oxidative species from microglia. The Veri‐T trial (NCT05184569) explores the therapeutic potential of verdiperstat and is the first clinical trial to focus on patients suffering from svPPA.MethodsVeri‐T is a multisite, phase 1, randomized, double‐blind, placebo‐controlled trial. N = 64 participants with svPPA will be randomized 3:1 to oral verdiperstat (titrated to a dose of 600mg BID) or placebo for 6 months of double‐blind therapy. Neuropsychological assessments, plasma, CSF, and volumetric brain imaging are collected prior to and upon conclusion of treatment. Recruitment is ongoing at 5 ARTFL LEFFTDS Longitudinal FTLD (ALLFTD) research network clinical centers.ResultsThe primary objective is to determine the safety and tolerability of verdiperstat in svPPA. The secondary objective is to determine the pharmacokinetic profile of verdiperstat in this cohort. Exploratory endpoints are focused on identifying potential pharmacodynamic effects and identifying endpoints for future efficacy trials including plasma myeloperoxidase activity, CSF biomarkers of glial activity (chitinase‐family proteins), neurodegeneration (neurofilament light chain), and unbiased CSF proteomics (Somalogics), as well volumetric MRI changes unique to svPPA, and cognitive and language impairments measured using the ALLFTD Mobile App.ConclusionThe Veri‐T trial examines the safety, tolerability and pharmacokinetic properties of verdiperstat in svPPA, and explores novel pharmacodynamic biomarkers and outcome measures that could be employed in future efficacy studies. Veri‐T is the first multicenter clinical trial of a potentially disease modifying agent for svPPA, and the first to leverage resources of the ALLFTD network.