Search

Background: Ublituximab is a novel anti-CD20 monoclonal antibody glycoengineered for enhanced antibody-dependent cellular cytotoxicity. The phase 3 ULTIMATE I and II studies showed significant improvements in annualized relapse rate, total number of gadolinium-enhancing (Gd+) T1 lesions, and total number of new or enlarging T2 at Week 96, as well as improvement in the proportion of participants with no evidence of disease activity (NEDA) from Weeks 24-96 with ublituximab vs. teriflunomide., Methods: In ULTIMATE I (NCT03277261; www.clinicaltrials.gov) ( N = 549) and II (NCT03277248; www.clinicaltrials.gov) ( N = 545), participants with relapsing multiple sclerosis received ublituximab 450 mg intravenous infusion every 24 weeks (following Day 1 infusion of 150 mg and Day 15 infusion of 450 mg) or teriflunomide 14 mg oral once daily for 96 weeks. Pooled post hoc analyses evaluated NEDA by treatment epoch and participant subtype: age ( ≤ 38 or >38 years), early or later disease (<3 or ≥3 years following diagnosis), treatment history (treatment naïve or previously treated), 0 or ≥1 Gd+ T1 lesions at baseline, and Expanded Disability Status Scale score ≤ 3.5 or >3.5 at baseline. NEDA was defined as no confirmed relapses, no Gd+ T1 lesions, no new or enlarging T2 lesions, and no disability progression confirmed for ≥12 weeks., Results: NEDA rates in the ublituximab vs. teriflunomide cohorts by treatment epoch were: Weeks 0-96, 44.6% vs. 12.4% (3.6 × improvement); Weeks 24-96 (re-baselined), 82.1% vs. 22.5% (3.6 × improvement); and Weeks 48-96 (re-baselined), 88.2% vs. 30.4% (2.9 × improvement) (all p < 0.0001). The primary driver of disease activity in ublituximab-treated participants was new or enlarging T2 lesions during Weeks 0-24. 41.8% of ublituximab-treated participants who had evidence of disease activity in the first year (Weeks 0-48) experienced NEDA in the second year of treatment (Weeks 48-96) compared with 17.3% of teriflunomide-treated participants. At Weeks 24-96 (re-baselined), rates of NEDA were significantly higher with ublituximab than teriflunomide in all participant subtypes (all p < 0.0001)., Conclusions: ULTIMATE I and II pooled post hoc analyses demonstrated a consistent NEDA benefit among ublituximab-treated participants across treatment epochs and key participant subpopulations., Competing Interests: EA has received compensation for advisory boards, lectures, and consultancy with Actelion/Janssen, Alexion, Bayer, Biogen, Celgene/BMS, EMD Serono/Merck, Genentech/Roche, Genzyme, Novartis, Sanofi, and TG Therapeutics; research support from Biogen, Genentech/Roche, Novartis, TG Therapeutics, Patient-Centered Outcomes Research Initiative, National Multiple Sclerosis Society, National Institutes of Health, and Rocky Mountain MS Center. LS has received compensation for consulting from TG Therapeutics. H-PH has received honoraria for serving on steering or data monitoring committees or speaker fees from Bayer, Biogen, Boehringer Ingelheim, BMS Celgene, GeNeuro, Merck, Novartis, Sanofi, TG Therapeutics, and Roche with approval by the Rector of Heinrich-Heine-Universität. PQ has received speaking and consulting honoraria from Biogen, BMS, Genzyme, Genentech, Viela Bio, and TG Therapeutics. SW has received compensation for consulting from TG Therapeutics; has been a consultant, speaker, and research participant for Celgene/BMS, Biogen, EMD Serono, Genentech/Roche, and Genzyme/Sanofi; has conducted research/been a consultant for Novartis, and has conducted research for Alkermes and TG Therapeutics. DR has received consultancy fees from Greenwich Biosciences, Mallinckrodt, and Novartis; honoraria or speaker fees and consultancy fees from Alexion, Amgen, Biogen, Bristol Myers Squibb, EMD Serono, Genentech, Horizon, ImmPACT Bio, Janssen, Sanofi Genzyme, and TG Therapeutics; research grant support from Anokion, Atara Biotherapeutics, Biogen, CorEvitas, EMD Serono, Genentech, GW Pharmaceuticals, Janssen, Novartis, PCORI, PRIME CME, Sanofi Genzyme, TG Therapeutics, and UCB. KS has received honoraria for speaking, consulting, and serving on advisory boards from Merck, Novartis, Roche, Biogen, Celgene, BMS, and TG Therapeutics. DW's employer has received research funding, speaking fees, or he has served as expert witness for AbbVie, Adamas, Allergan, ANI Pharma, Avanir, Banner Life, Biogen, Bristol Myers Squibb, Chugai, Eli Lilly, EMD Serono, Genentech, GW Therapeutics, Immunic, InnoCare, Janssen, Jazz Pharmaceuticals, Mallinckrodt, MAPI Therapeutics, Mylan, National MS Society, Novartis, SanBio, Sanofi Genzyme, UCB Biopharma, Viela Bio, Teva Pharmaceuticals, and TG Therapeutics and was employed by Consultants in Neurology. EF, KM, YX, KB, and HM are employees of TG Therapeutics. BC has received personal compensation for consulting from Alexion, Atara, Autobahn, Avotres, Biogen, Boston Pharma, EMD Serono, Gossamer Bio, Hexal/Sandoz, Horizon, Immunic AG, Kyverna, Neuron23, Novartis, Sanofi, Siemens, and TG Therapeutics and received research support from Genentech and Kyverna. The authors declare that this study received funding from TG Therapeutics. The funder was involved in the study design, collection, analysis, interpretation of data, the writing of this article, and the decision to submit for publication. All authors had full editorial oversight of the manuscript and provided final approval for all content. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Alvarez, Steinman, Fox, Hartung, Qian, Wray, Robertson, Selmaj, Wynn, Mok, Xu, Bodhinathan, Miskin and Cree.)

Background: Loss of brain gray matter fractional volume predicts multiple sclerosis (MS) progression and is associated with worsening physical and cognitive symptoms. Within deep gray matter, thalamic damage is evident in early stages of MS and correlates with physical and cognitive impairment. Natalizumab is a highly effective treatment that reduces disease progression and the number of inflammatory lesions in patients with relapsing-remitting MS (RRMS)., Objective: To evaluate the effect of natalizumab on gray matter and thalamic atrophy., Methods: A combination of deep learning-based image segmentation and data augmentation was applied to MRI data from the AFFIRM trial., Results: This post hoc analysis identified a reduction of 64.3% ( p = 0.0044) and 64.3% ( p = 0.0030) in mean percentage gray matter volume loss from baseline at treatment years 1 and 2, respectively, in patients treated with natalizumab versus placebo. The reduction in thalamic fraction volume loss from baseline with natalizumab versus placebo was 57.0% at year 2 ( p < 0.0001) and 41.2% at year 1 ( p = 0.0147). Similar findings resulted from analyses of absolute gray matter and thalamic fraction volume loss., Conclusion: These analyses represent the first placebo-controlled evidence supporting a role for natalizumab treatment in mitigating gray matter and thalamic fraction atrophy among patients with RRMS., Clinicaltrials.gov Identifier: NCT00027300URL: https://clinicaltrials.gov/ct2/show/NCT00027300., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: KN received licensing fees from Biogen; research funding to institution from Biogen, National Institutes of Health, National Multiple Sclerosis Society, Novartis, Patient-Centered Outcomes Research Institute (PCORI), Sanofi Genzyme, US Department of Defense. ZS, CH-C, KB, and RLA are employees of and own stock and/or stock options in Biogen. KB was an employee of and owned stock and/or stock options in Biogen at the time the research was conducted.

Background: Aggressive disease control soon after multiple sclerosis (MS) diagnosis may prevent irreversible neurological damage, and therefore early initiation of a high-efficacy disease-modifying therapy (DMT) is of clinical relevance., Objectives: Evaluate long-term clinical outcomes in patients with MS who initiated treatment with either natalizumab or a BRACETD therapy (interferon beta, glatiramer acetate, teriflunomide, or dimethyl fumarate)., Design: This retrospective analysis utilized data from MSBase to create a matched population allowing comparison of first-line natalizumab to first-line BRACETD., Methods: This study included patients who initiated treatment either with natalizumab or a BRACETD DMT within 1 year of MS diagnosis and continued treatment for ⩾6 months, after which patients could switch DMTs or discontinue treatment. Patients had a minimum follow-up time of ⩾60 months from initiation. A subgroup analysis compared the natalizumab group to patients in the BRACETD group who escalated therapy after 6 months. Outcomes included unadjusted annualized relapse rates (ARRs), time-to-first relapse, time-to-first confirmed disability improvement (CDI), and time-to-first confirmed disability worsening (CDW)., Results: After 1:1 propensity score matching, 355 BRACETD patients were matched to 355 natalizumab patients. Patients initiating natalizumab were less likely to experience a relapse over the duration of follow-up, with ARRs [95% confidence interval (CI)] of 0.080 (0.070-0.092) for natalizumab patients and 0.191 (0.178-0.205) for BRACETD patients ( p  < 0.0001). A Cox regression model of time-to-first relapse showed a reduced risk of relapse for natalizumab patients [hazard ratio (95% CI) of 0.52 (0.42-0.65); p  < 0.001] and a more favorable time-to-first CDI. The risk of CDW was similar between groups. The subgroup analysis showed an increased relapse risk as well as a significantly higher risk of CDW for BRACETD patients., Conclusion: Early initiation of natalizumab produced long-term benefits in relapse outcomes in comparison with BRACETD, regardless of a subsequent escalation in therapy., (© The Author(s), 2024.)

Background: Natalizumab (TYSABRI®) 300 mg administered intravenously every-4-weeks (Q4W) is approved for treatment of relapsing-remitting multiple sclerosis but is associated with increased risk of progressive multifocal leukoencephalopathy (PML). Extended natalizumab dosing intervals of approximately every-6-weeks (Q6W) are associated with a lower risk of PML. Primary and secondary clinical outcomes from the NOVA randomized clinical trial (NCT03689972) suggest that effective disease control is maintained in patients who were stable during treatment with natalizumab Q4W for ≥12 months and who then switched to Q6W dosing. We compared additional exploratory clinical and patient-reported outcomes (PROs) from NOVA to assess the efficacy of Q6W dosing., Methods: Prespecified exploratory clinical efficacy endpoints in NOVA included change from baseline in Expanded Disability Status Scale (EDSS) score, Timed 25-Foot Walk (T25FW), dominant- and nondominant-hand 9-Hole Peg Test (9HPT), and Symbol Digit Modalities Test (SDMT). Exploratory patient-reported outcome (PRO) efficacy endpoints included change from baseline in the Treatment Satisfaction Questionnaire for Medication (TSQM), Neuro-QoL fatigue questionnaire, Multiple Sclerosis Impact Scale (MSIS-29), EuroQol 5 Dimensions (EQ-5D-5 L) index score, Clinical Global Impression (CGI)-Improvement (patient- and clinician-assessed) and CGI-Severity (clinician-assessed) rating scales. Estimated proportions of patients with confirmed EDSS improvement were based on Kaplan-Meier methods. Estimates of mean treatment differences for Q6W versus Q4W in other outcomes were assessed by least squares mean (LSM) and analyzed using a linear mixed model of repeated measures or ordinal logistic regression (CGI-scale)., Results: Exploratory clinical and patient-reported outcomes were assessed in patients who received ≥1 dose of randomly assigned study treatment and had ≥1 postbaseline efficacy assessment (Q6W group, n = 247, and Q4W group, n = 242). Estimated proportions of patients with EDSS improvement at week 72 were similar for Q6W and Q4W groups (11.7% [19/163] vs 10.8% [17/158]; HR 1.02 [95% confidence interval [CI], 0.53-1.98]; P = 0.9501). At week 72, there were no significant differences between Q6W and Q4W groups in LSM change from baseline for T25FW (0.00, P = 0.975), 9HPT (dominant [0.22, P = 0.533] or nondominant [0.09, P = 0.862] hand), or SDMT (-1.03, P = 0.194). Similarly, there were no significant differences between Q6W and Q4W groups in LSM change from baseline for any PRO (TSQM, -1.00, P = 0.410; Neuro-QoL fatigue, 0.52, P = 0.292; MSIS-29 Psychological, 0.67, P = 0.572; MSIS-29 Physical, 0.74, P = 0.429; EQ-5D-5 L, 0.00, P = 0.978). For the EQ-5D-5 L, a higher proportion of Q6W patients than Q4W patients demonstrated worsening (≥0.5 standard deviation increase in the EQ-5D-5 L index score; P = 0.0475). From baseline to week 72 for Q6W versus Q4W, odds ratio (ORs) of LSM change in CGI scores did not show meaningful differences between groups (CGI-Improvement [patient]: OR [95% CI] 1.2 [0.80-1.73]; CGI-Improvement [physician]: 0.8 [0.47-1.36]; CGI-Severity [physician]: 1.0 [0.71-1.54])., Conclusions: No significant differences were observed in change from baseline to week 72 between natalizumab Q6W and Q4W groups for all exploratory clinical or PRO-related endpoints assessed. For the EQ-5D-5 L, a higher proportion of Q6W than Q4W patients demonstrated worsening., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Aim: Patients with relapsing-remitting multiple sclerosis (RRMS) treated with natalizumab have anecdotally reported a 'feel-good experience' (FGE). The authors characterized the FGE using survey data from patients with RRMS treated with natalizumab or other disease-modifying therapies (other-DMT). Methods: Questionnaire data from RRMS patients who use MyMSTeam, an online patient social network, were analyzed. Results: The survey included 347 patients (95 natalizumab; 252 other-DMT). More natalizumab than other-DMT patients self-reported having an FGE (62.1 vs 44.8%; p = 0.001) as well as other physical, emotional and cognitive benefits. Conclusion: This study demonstrates that physical, emotional and cognitive benefits were more commonly reported by patients treated with natalizumab than those treated with other disease-modifying therapies and helps characterize patient-reported factors associated with the FGE.

Synaptic and neuronal loss are major neuropathological characteristics of Parkinson's disease. Misfolded protein aggregates in the form of Lewy bodies, comprised mainly of α-synuclein (αSyn), are associated with disease progression, and have also been linked to other neurodegenerative diseases, including Lewy body dementia, Alzheimer's disease, and frontotemporal dementia. However, the effects of αSyn and its mechanism of synaptic damage remain incompletely understood. Here, we show that αSyn oligomers induce Ca 2+ -dependent release of glutamate from astrocytes obtained from male and female mice, and that mice overexpressing αSyn manifest increased tonic release of glutamate in vivo In turn, this extracellular glutamate activates glutamate receptors, including extrasynaptic NMDARs (eNMDARs), on neurons both in culture and in hippocampal slices of αSyn-overexpressing mice. Additionally, in patch-clamp recording from outside-out patches, we found that oligomerized αSyn can directly activate eNMDARs. In organotypic slices, oligomeric αSyn induces eNMDAR-mediated synaptic loss, which can be reversed by the drug NitroSynapsin. When we expose human induced pluripotent stem cell-derived cerebrocortical neurons to αSyn, we find similar effects. Importantly, the improved NMDAR antagonist NitroSynapsin, which selectively inhibits extrasynaptic over physiological synaptic NMDAR activity, protects synapses from oligomeric αSyn-induced damage in our model systems, thus meriting further study for its therapeutic potential. SIGNIFICANCE STATEMENT Loss of synaptic function and ensuing neuronal loss are associated with disease progression in Parkinson's disease (PD), Lewy body dementia (LBD), and other neurodegenerative diseases. However, the mechanism of synaptic damage remains incompletely understood. α-Synuclein (αSyn) misfolds in PD/LBD, forming Lewy bodies and contributing to disease pathogenesis. Here, we found that misfolded/oligomeric αSyn releases excessive astrocytic glutamate, in turn activating neuronal extrasynaptic NMDA receptors (eNMDARs), thereby contributing to synaptic damage. Additionally, αSyn oligomers directly activate eNMDARs, further contributing to damage. While the FDA-approved drug memantine has been reported to offer some benefit in PD/LBD (Hershey and Coleman-Jackson, 2019), we find that the improved eNMDAR antagonist NitroSynapsin ameliorates αSyn-induced synaptic spine loss, providing potential disease-modifying intervention in PD/LBD., (Copyright © 2021 the authors.)

Stroke and vascular dementia are leading causes of morbidity and mortality. Neuroprotective therapies have been proposed but none have proven clinically tolerated and effective. While overstimulation of N-methyl-d-aspartate-type glutamate receptors (NMDARs) is thought to contribute to cerebrovascular insults, the importance of NMDARs in physiological function has made this target, at least in the view of many in 'Big Pharma,' 'undruggable' for this indication. Here, we describe novel NitroMemantine drugs, comprising an adamantane moiety that binds in the NMDAR-associated ion channel that is used to target a nitro group to redox-mediated regulatory sites on the receptor. The NitroMemantines are both well tolerated and effective against cerebral infarction in rodent models via a dual allosteric mechanism of open-channel block and NO/redox modulation of the receptor. Targeted S-nitrosylation of NMDARs by NitroMemantine is potentiated by hypoxia and thereby directed at ischemic neurons. Allosteric approaches to tune NMDAR activity may hold therapeutic potential for cerebrovascular disorders.

Alcohol (ethanol)-induced behaviors may arise from direct interaction of alcohol with discrete protein cavities within brain proteins. Recent structural and biochemical studies have provided new insights into the mechanism of alcohol-dependent activation of G protein-gated inwardly rectifying potassium (GIRK) channels, which regulate neuronal responses in the brain reward circuit. GIRK channels contain an alcohol binding pocket formed at the interface of two adjacent channel subunits. Here, we discuss the physiochemical properties of the alcohol pocket and the roles of G protein βγ subunits and membrane phospholipid PIP2 in regulating the alcohol response of GIRK channels. Some of the features of alcohol modulation of GIRK channels may be common to other alcohol-sensitive brain proteins. We discuss the possibility of alcohol-selective therapeutics that block alcohol access to the pocket. Understanding alcohol recognition and modulation of brain proteins is essential for development of therapeutics for alcohol abuse and addiction.

Alcohol (ethanol) produces a wide range of pharmacological effects on the nervous system through its actions on ion channels. The molecular mechanism underlying ethanol modulation of ion channels is poorly understood. Here we used a unique method of alcohol-tagging to demonstrate that alcohol activation of a G-protein-gated inwardly rectifying potassium (GIRK or Kir3) channel is mediated by a defined alcohol pocket through changes in affinity for the membrane phospholipid signaling molecule phosphatidylinositol 4,5-bisphosphate. Surprisingly, hydrophobicity and size, but not the canonical hydroxyl, were important determinants of alcohol-dependent activation. Altering levels of G protein Gβγ subunits, conversely, did not affect alcohol-dependent activation, suggesting a fundamental distinction between receptor and alcohol gating of GIRK channels. The chemical properties of the alcohol pocket revealed here might extend to other alcohol-sensitive proteins, revealing a unique protein microdomain for targeting alcohol-selective therapeutics in the treatment of alcoholism and addiction.

G protein-gated inwardly rectifying potassium (GIRK) channels play an important role in regulating neuronal excitability. Sorting nexin 27b (SNX27b), which reduces surface expression of GIRK channels through a PDZ domain interaction, contains a putative Ras-association (RA) domain with unknown function. Deleting the RA domain in SNX27b (SNX27b-ΔRA) prevents the down-regulation of GIRK2c/GIRK3 channels. Similarly, a point mutation (K305A) in the RA domain disrupts regulation of GIRK2c/GIRK3 channels and reduces H-Ras binding in vitro. Finally, the dominant-negative H-Ras (S17N) occludes the SNX27b-dependent decrease in surface expression of GIRK2c/GIRK3 channels. Thus, the presence of a functional RA domain and the interaction with Ras-like G proteins comprise a novel mechanism for modulating SNX27b control of GIRK channel surface expression and cellular excitability.

We previously identified a set of 50 genes that were differentially transcribed in the hippocampal CA1 region of aged, learning-impaired rats compared to aged, superior learning animals during a Morris water maze paradigm. In the current study, we expressed three of these genes (Pctk1, Tcf12 and Ccnd1), which had shown increased transcription in aged, learning impaired rats, in the hippocampus of young rats using viral gene transfer and tested for learning and memory deficits at age 7-14months. Pctk1 injected animals displayed a modest deficit in acquiring latency in both the Morris water maze and the reverse Morris maze. In the radial arm water maze paradigm, Pctk1, Tcf12 and Ccnd1 expressing animals all showed significant deficits in spatial working memory compared to controls. Rats injected with Ccnd1 and Tcf12, but not Pctk1, also showed a significant deficit in spatial reference memory in the radial arm water maze. Electrophysiological experiments revealed no difference in LTP in Ccnd1 and Pctk1 animals. However, LTD induced by low frequency stimulation was observed in control and Ccnd1 animals, but not in Pctk1 treated animals. In addition, neither Ccnd1 nor Pctk1 expression produced any detectable neuropathology. In contrast Tcf12 expressing animals displayed significant neurodegeneration in both CA1 and dentate gyrus. Several Tcf12 animals also developed tumors that appeared to be glioblastomas, suggesting that aberrant Tcf12 expression in the hippocampus is tumorigenic. Thus, behavioral experiments suggested that overexpression of Pctk1 and Ccnd1 produce a deficit in learning and memory, but electrophysiological experiments do not point to a simple mechanism. In contrast, the learning and memory deficits in Tcf12 animals are likely due to neuropathology associated with Tcf12 gene expression., (Copyright © 2011 Elsevier Inc. All rights reserved.)

A decrease in the excitability of CA1 pyramidal neurons contributes to the age related decrease in hippocampal function and memory decline. Decreased neuronal excitability in aged neurons can be observed as an increase in the Ca(2+)- activated K(+)- mediated post burst afterhyperpolarization (AHP). In this study, we demonstrate that the slow component of AHP (sAHP) in aged CA1 neurons (aged-sAHP) is decreased ∼50% by application of the reducing agent dithiothreitol (DTT). The DTT-mediated decrease in the sAHP was age specific, such that it was observed in CA1 pyramidal neurons of aged (20-25 mo), but not young (6-9 mo) F344 rats. The effect of DTT on the aged-sAHP was blocked following depletion of intracellular Ca(2+) stores (ICS) by thapsigargin or blockade of ryanodine receptors (RyRs) by ryanodine, suggesting that the age-related increase in the sAHP was due to release of Ca(2+) from ICS through redox sensitive RyRs. The DTT-mediated decrease in the aged-sAHP was not blocked by inhibition of L-type voltage gated Ca(2+) channels (L-type VGCC), inhibition of Ser/Thr kinases, or inhibition of the large conductance BK potassium channels. The results add support to the idea that a shift in the intracellular redox state contributes to Ca(2+) dysregulation during aging.

Calcium (Ca(2+)) is a highly versatile intracellular signaling molecule that is essential for regulating a variety of cellular and physiological processes ranging from fertilization to programmed cell death. Research has provided ample evidence that brain aging is associated with altered Ca(2+) homeostasis. Much of the work has focused on the hippocampus, a brain region critically involved in learning and memory, which is particularly susceptible to dysfunction during senescence. The current review takes a broader perspective, assessing age-related changes in Ca(2+) sources, Ca(2+) sequestration, and Ca(2+) binding proteins throughout the nervous system. The nature of altered Ca(2+) homeostasis is cell specific and may represent a deficit or a compensatory mechanism, producing complex patterns of impaired cellular function. Incorporating the knowledge of the complexity of age-related alterations in Ca(2+) homeostasis will positively shape the development of highly effective therapeutics to treat brain disorders.