Natalizumab reduces loss of gray matter and thalamic volume in patients with relapsing-remitting multiple sclerosis: A post hoc analysis from the randomized, placebo-controlled AFFIRM trial.

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.

The impact of social distancing measures on anti-JC virus serostatus changes before and during the COVID-19 pandemic in US patients with multiple sclerosis.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic offered an epidemiological opportunity to evaluate if isolation and masking affected John Cunningham (JC) virus transmission. OBJECTIVE: This study aimed to assess the proportion of natalizumab-treated patients who converted to a positive anti-JCV antibody serostatus before and during the pandemic. METHODS: Data from TYSABRI Outreach: Unified Commitment to Health (TOUCH) for 22,375 US patients treated with natalizumab with anti-JCV antibody records were assessed in epochs annually from 2017 to 2022. RESULTS: Pre-pandemic anti-JCV antibody serostatus change was observed for 7.4%-7.7%. During the first and second years of the pandemic, 7.3% and 7.2% of patients' serostatus changed, respectively. CONCLUSION: The proportion of patients with anti-JCV antibody serostatus change did not significantly differ during the first 2 years of the pandemic compared with prior years. In contrast to seasonal influenza, masking and social distancing had no discernable effect on JCV serostatus change.

ZFP191 is required by oligodendrocytes for CNS myelination.

The controlling factors that prompt mature oligodendrocytes to myelinate axons are largely undetermined. In this study, we used a forward genetics approach to identify a mutant mouse strain characterized by the absence of CNS myelin despite the presence of abundant numbers of late-stage, process-extending oligodendrocytes. Through linkage mapping and complementation testing, we identified the mutation as a single nucleotide insertion in the gene encoding zinc finger protein 191 (Zfp191), which is a widely expressed, nuclear-localized protein that belongs to a family whose members contain both DNA-binding zinc finger domains and protein-protein-interacting SCAN domains. Zfp191 mutants express an array of myelin-related genes at significantly reduced levels, and our in vitro and in vivo data indicate that mutant ZFP191 acts in a cell-autonomous fashion to disrupt oligodendrocyte function. Therefore, this study demonstrates that ZFP191 is required for the myelinating function of differentiated oligodendrocytes.

Cuprizone Intoxication Induces Cell Intrinsic Alterations in Oligodendrocyte Metabolism Independent of Copper Chelation.

Cuprizone intoxication is a common animal model used to test myelin regenerative therapies for the treatment of diseases such as multiple sclerosis. Mice fed this copper chelator develop reversible, region-specific oligodendrocyte loss and demyelination. While the cellular changes influencing the demyelinating process have been explored in this model, there is no consensus about the biochemical mechanisms of toxicity in oligodendrocytes and about whether this damage arises from the chelation of copper in vivo. Here we have identified an oligodendroglial cell line that displays sensitivity to cuprizone toxicity and performed global metabolomic profiling to determine biochemical pathways altered by this treatment. We link these changes with alterations in brain metabolism in mice fed cuprizone for 2 and 6 weeks. We find that cuprizone induces widespread changes in one-carbon and amino acid metabolism as well as alterations in small molecules that are important for energy generation. We used mass spectrometry to examine chemical interactions that are important for copper chelation and toxicity. Our results indicate that cuprizone induces global perturbations in cellular metabolism that may be independent of its copper chelating ability and potentially related to its interactions with pyridoxal 5'-phosphate, a coenzyme essential for amino acid metabolism.

Comparison of time to clinically meaningful improvement in quality of life in neurological disorders in patients treated with natalizumab versus ocrelizumab.

Aim: To assess time to improvement in Quality of Life in Neurological Disorders (Neuro-QoL) domains for patients treated with natalizumab versus ocrelizumab. Methods: Patients enrolled in the MS PATHS network who initiated treatment with either natalizumab or ocrelizumab rated the Neuro-QoL domains of physical function, symptoms, emotional health, cognitive function and social ability. Results: Time to clinically meaningful improvement was significantly shorter with natalizumab versus ocrelizumab for cognitive function (event time ratio [95% CI]: 0.37 [0.24-0.57]; p < 0.001), sleep disturbance (0.45 [0.28-0.72]; p = 0.001), social role participation (0.37 [0.21-0.66]; p = 0.001) and social role satisfaction (0.5 [0.31-0.8]; p = 0.004). Conclusion: Natalizumab had shorter time to clinically meaningful improvement in cognitive, sleep, and social role Neuro-QoL domains versus ocrelizumab.

Knowledge of treatment-related benefits associated with medication choices, including improvement of quality of life (QoL), are strong influential factors for patients to start and continue their therapies. Little is known about patient-reported time to onset of functional improvement upon the initiation of medications for multiple sclerosis (MS). The Multiple Sclerosis Partners Advancing Technology and Health Solutions (MS PATHS) network, a repository of collaborative international data on routine MS management, includes patient-reported information on the health-related QoL using the Quality of Life in Neurological Disorders (Neuro-QoL) measure. This study included data from 883 eligible patients enrolled in MS PATHS, with the aim of assessing and comparing the time to improvement in physical, mental and social health for patients treated with natalizumab versus ocrelizumab using Neuro-QoL. Natalizumab and ocrelizumab are both high-efficacy treatment options for relapsing forms of MS. The results demonstrated that, compared with ocrelizumab, natalizumab treatment led to faster effect on mental and social health, as well as quicker improvements in physical functioning in the arms and hands. Overall, it took shorter time for natalizumab-treated patients to achieve better QoL compared with ocrelizumab. These findings highlight the importance of QoL in disease management and provide a patient perspective for healthcare providers when making decisions about high-efficacy treatments for their patients with MS.

Patterns of disease-modifying therapy utilization before, during, and after pregnancy and postpartum relapses in women with multiple sclerosis.

BACKGROUND: Pregnancy is a common consideration for people with multiple sclerosis (pwMS); MS onset is typically between 20 and 45 years of age, during potential child-bearing years. Pregnancy and postpartum care are a significant factor influencing disease-modifying therapy (DMT) selection for many pwMS. To date, few DMTs are considered safe to continue during pregnancy and real-world treatment patterns before, during, and after pregnancy remain uncharacterized. Evolving guidance is needed regarding how to optimize management of the pregnancy and postpartum periods considering the changing DMT landscape. This analysis in two large claims databases describes DMT utilization for the treatment of MS before, during, and after pregnancy and relapse patterns during pregnancy and postpartum. METHODS: In this retrospective, observational study, the US MarketScan Commercial and Medicaid claims database was assessed for female patients aged 18-55 years with ≥1 insurance claim submitted under the diagnosis code of MS from 01 January 2016-30 April 2021 and continuous enrollment eligibility from ≥6 months prior to pregnancy date (preconception) through 6 months of follow-up following delivery (postpartum period). Comorbid conditions were examined preconception and postpartum, including anxiety and depression. Moderate/severe relapse was defined as MS-related hospitalization, or an outpatient visit and one claim within 7 days of the visit with steroids or total plasma exchange. RESULTS: A total of 944 patients (mean [standard deviation] age, 32.4 [5.0] years) were eligible; 688 (73%) were commercially insured and 256 (27%) received Medicaid. Compared with commercially-insured patients, use of DMTs was lower among Medicaid patients at 6 months preconception (25.4% vs 40.4%; p < 0.001), with similar patterns observed both during pregnancy and postpartum. Overall, prevalence of DMT use declined sharply during pregnancy, from 36.3% of patients in the 6 months preconception to 17.9%, 5.3%, and 5.8% in trimesters 1, 2 and 3, respectively. Postpartum DMT utilization increased to 20.9% at 0-3 months and 24.4% at 4-6 months. Of all patients in the preconception period, the most frequently used DMTs were glatiramer acetate (14.3%), dimethyl fumarate (6.0%), interferon (5.2%), and natalizumab (4.9%). Due to small sample size, information was limited for anti-CD20s and alemtuzumab. The proportion of patients with any moderate/severe relapse declined over pregnancy (preconception, n = 82 [8.7%]; pregnancy, n = 25 [2.6%]), but increased postpartum (n = 94 [10.0%]). Of the 889 patients who stopped DMT during pregnancy, the risk of postpartum relapses was lower in the patients who resumed DMT postpartum (10/192) than in patients who did not (76/697) (5.2% vs 10.9%; odds ratio, 0.455 [95% confidence interval 0.216-0.860], p = 0.018). Cases of postpartum depression and anxiety were significantly lower in commercially-insured patients vs Medicaid patients (postpartum depression, 13.7% vs 27.0%, p < 0.01; postpartum anxiety, 16.3% vs 30.5%, p < 0.01). CONCLUSION: DMT utilization declined sharply during pregnancy; it gradually increased postpartum but remained below pre-pregnancy use. The proportion of pwMS experiencing a moderate/severe relapse and number of relapses declined over pregnancy but increased postpartum. Reinitiation of DMT during the postpartum period was associated with lower risk of relapses, supporting a role for early reinitiation of DMT postpartum. STUDY SUPPORTED BY: Biogen.

Temporal Relationship Between Serum Neurofilament Light Chain and Radiologic Disease Activity in Patients With Multiple Sclerosis.

BACKGROUND AND OBJECTIVES: Serum neurofilament light chain (sNfL) levels correlate with multiple sclerosis (MS) disease activity, but the dynamics of this correlation are unknown. We evaluated the relationship between sNfL levels and radiologic MS disease activity through monthly assessments during the 24-week natalizumab treatment interruption period in RESTORE (NCT01071083). METHODS: In the RESTORE trial, participants with relapsing forms of MS who had received natalizumab for ≥12 months were randomized to either continue or stop natalizumab and followed with MRI and blood draws every 4 weeks to week 28 and again at week 52 The sNfL was measured, and its dynamics were correlated with the development of gadolinium-enhancing (Gd+) lesions. Log-linear trend in sNfL levels were modeled longitudinally using generalized estimating equations with robust variance estimator from baseline to week 28. RESULTS: Of 175 patients enrolled in RESTORE, 166 had serum samples for analysis. Participants with Gd+ lesions were younger (37.7 vs 43.1, p = 0.001) and had lower Expanded Disability Status Scale scores at baseline (2.7 vs 3.4, p = 0.017) than participants without Gd+ lesions. sNfL levels increased in participants with Gd+ lesions (n = 65) compared with those without (n = 101, mean change from baseline to maximum sNfL value, 12.1 vs 3.2 pg/mL, respectively; p = 0.003). As the number of Gd+ lesions increased, peak median sNfL change also increased by 1.4, 3.0, 4.3, and 19.6 pg/mL in the Gd+ lesion groups of 1 (n = 12), 2-3 (n = 18), 4-9 (n = 21), and ≥10 (n = 14) lesions, respectively. However, 46 of 65 (71%) participants with Gd+ lesions did not increase above the 95th percentile threshold of the group without Gd+ lesions. The initial increase of sNfL typically trailed the first observation of Gd+ lesions, and the peak increase in sNfL was a median [interquartile range] of 8 [0, 12] weeks after the first appearance of the Gd+ lesion. DISCUSSION: Although sNfL correlated with the presence of Gd+ lesions, most participants with Gd+ lesions did not have elevations in sNfL levels. These observations have implications for the use and interpretation of sNfL as a biomarker for monitoring MS disease activity in controlled trials and clinical practice.

Characterizing the 'feel-good experience' in multiple sclerosis patients treated with natalizumab or other therapies.

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.

Patient-reported outcomes are the strongest predictors of disease disability in intramuscular interferon ß-1a users.

Introduction: Patient-reported outcomes (PROs) are valuable measures for routine clinical care of people with multiple sclerosis (pwMS). Materials: 646 pwMS treated with interferon-ß-1a (IFN-ß-1a) were retrospectively included from the New York State Multiple Sclerosis Consortium. Clinical and PRO data at enrollment and 3 year follow-up were collected. PwMS with stable disease and disability worsening were matched (1:1) based on age, Expanded Disability Status Scale (EDSS) scores and disease duration. Disability worsening was determined based on trial criteria. Results: PwMS with future EDSS worsening had higher baseline and follow-up timed-25-foot walk (6.6 vs 5.5 s; 9.1 vs 5.5 s; p < 0.001) when compared with stable pwMS. Worsening pwMS reported higher baseline difficulties in getting up (odds ratio [OR] = 2.4; p = 0.009), climbing stairs (OR = 1.6; p = 0.024) and standing (OR = 2.2; p < 0.001). Worsening pwMS reported greater lower limb limitations (OR = 2.3; p = 0.004) and fatigue (OR = 1.8; p = 0.002). Conclusion: Higher fatigue and lower limb functional limitations are significant predictors of future disability worsening in pwMS.

A large retrospective study was carried out on people with multiple sclerosis (PwMS) being treated with intramuscular interferon-ß medication from the New York State Multiple Sclerosis Consortium. The aim of the study was to look at whether patient-reported and clinical measures could be used early on to predict whether PwMS have worsening of their disease. The study demonstrated that patient-reported levels of limitations in multiple physical and mental symptoms can predict future worsening in objectively quantified disability in PwMS who take intramuscular interferon-ß medication. Reported limitations in lower extremities and fatigue were the most predictive of future disability worsening.

Correction to: Improvements in Cognitive Processing Speed, Disability, and Patient­Reported Outcomes in Patients with Early Relapsing­Remitting Multiple Sclerosis Treated with Natalizumab: Results of a 4­year, Real­World, Open­Label Study.

BACKGROUND: STRIVE was a prospective, 4-year, multicenter, observational, open-label, single-arm study of natalizumab treatment in anti-JC virus antibody-negative patients with early relapsing-remitting multiple sclerosis (RRMS). OBJECTIVE: Study objectives examined the effects of natalizumab on cognitive processing speed, confirmed disability improvement (CDI), and patient-reported outcomes (PROs). METHODS: Clinical and PRO secondary endpoints were assessed annually over 4 years in STRIVE. The Symbol Digit Modalities Test (SDMT) was used as a measure of cognitive processing speed. PROs were assessed using the Multiple Sclerosis Impact Score (MSIS-29) and the Work Productivity and Activity Impairment Questionnaire (WPAI). RESULTS: At all four annual assessments, the proportion of patients in the intent-to-treat (ITT) population (N = 222) who exhibited clinically meaningful improvement in their SDMT score from baseline (i.e., change ≥ 4 points) ranged from 41.9 to 54.0%. The cumulative probability of CDI at 4 years in patients in the ITT population with a baseline Expanded Disability Status Scale score ≥ 2 (N = 133) was 43.9%. Statistically significant reductions in the mean change from screening in the MSIS-29 physical and psychological scores, indicating improved quality of life, were observed over all 4 years (P ≤ 0.0012 for all). A statistically significant decrease from screening in the impact of MS on regular activities, signifying an improvement in this WPAI measure, was also observed over all 4 years of the study. CONCLUSION: These results further extend our knowledge of the effectiveness, specifically regarding improvements in cognitive processing speed, disability and PROs, of long-term natalizumab treatment in early RRMS patients. CLINICALTRIALS: GOV: NCT01485003 (5 December 2011).

COVID-19 Vaccine Response in People with Multiple Sclerosis Treated with Dimethyl Fumarate, Diroximel Fumarate, Natalizumab, Ocrelizumab, or Interferon Beta Therapy.

BACKGROUND: Some multiple sclerosis (MS) disease-modifying therapies (DMTs) impair responses to vaccines, emphasizing the importance of understanding COVID-19 vaccine immune responses in people with MS (PwMS) receiving different DMTs. METHODS: This prospective, open-label observational study enrolled 45 participants treated with natalizumab (n = 12), ocrelizumab (n = 16), fumarates (dimethyl fumarate or diroximel fumarate, n = 11), or interferon beta (n = 6); ages 18-65 years inclusive; stable on DMT for at least 6 months. Responder rates, anti-SARS-CoV-2 spike receptor-binding domain IgG (anti-RBD) geometric mean titers (GMTs), antigen-specific T cells, and vaccination-related adverse events were evaluated at baseline and 8, 24, 36, and 48 weeks after first mRNA-1273 (Moderna) dose. RESULTS: At 8 weeks post vaccination, all natalizumab-, fumarate-, and interferon beta-treated participants generated detectable anti-RBD IgG titers, compared to only 25% of the ocrelizumab cohort. At 24 and 36 weeks post vaccination, natalizumab-, fumarate-, and interferon beta-treated participants continued to demonstrate detectable anti-RBD IgG titers, whereas participants receiving ocrelizumab did not. Anti-RBD GMTs decreased 81.5% between 8 and 24 weeks post vaccination for the non-ocrelizumab-treated participants, with no significant difference between groups. At 36 weeks post vaccination, ocrelizumab-treated participants had higher proportions of spike-specific T cells compared to other treatment groups. Vaccine-associated side effects were highest in the ocrelizumab arm for most symptoms. CONCLUSIONS: These results suggest that humoral response to mRNA-1273 COVID-19 vaccine is preserved and similar in PwMS treated with natalizumab, fumarate, and interferon beta, but muted with ocrelizumab. All DMTs had preserved T cell response, including the ocrelizumab cohort, which also had a greater risk of vaccine-related side effects.

Long-Term Effectiveness and Safety of Natalizumab in African American and Hispanic/Latino Patients with Early Relapsing-Remitting Multiple Sclerosis: STRIVE Data Analysis.

INTRODUCTION: In STRIVE, natalizumab treatment demonstrated effectiveness in clinical, magnetic resonance imaging (MRI), and patient-reported outcomes (PROs) in patients with early relapsing-remitting multiple sclerosis (RRMS). This post hoc analysis examined the effectiveness and safety of natalizumab in patients who self-identified as either Black/African American (AA) or Hispanic/Latino. METHODS: Clinical, MRI, and PROs were assessed for the Black/AA subgroup (n = 40) and compared with the non-Hispanic White subgroup (n = 158). As a result of the very small sample size, outcomes for the Hispanic/Latino subgroup (n = 18) were assessed separately, including a sensitivity analysis with Hispanic/Latino patients who completed the 4-year study on natalizumab. RESULTS: Clinical, MRI, and PROs were comparable between the Black/AA and non-Hispanic White subgroups except for MRI outcomes at year 1. A higher proportion of non-Hispanic White than Black/AA patients achieved MRI no evidence of disease activity (NEDA; 75.4% vs. 50.0%, p = 0.0121) and no new or newly enlarging T2 lesions (77.6% vs. 50.0%, p = 0.0031) at year 1; these differences were not observed in years 2-4 of the study. For the Hispanic/Latino subgroup in the intent-to-treat population, 46.2% and 55.6% achieved NEDA at years 1 and 2; 66.7% and 90.0% achieved clinical NEDA at years 3 and 4. Annualized relapse rate was reduced by 93.0% at year 1 versus the year before natalizumab initiation; this reduction was maintained throughout the study. Over 4 years, 37.5-50.0% of patients had a clinically meaningful improvement in their Symbol Digit Modalities Test score, and 81.8-100.0% and 90.9-100.0% had stable/improved Multiple Sclerosis Impact Scale-29 physical and psychological scores, respectively. Similar results were observed in the sensitivity analysis with Hispanic/Latino subgroup of the 4-year natalizumab completers. CONCLUSION: These results highlight the effectiveness and safety of natalizumab in patients with early RRMS who self-identified as Black/AA or Hispanic/Latino. CLINICALTRIALS: GOV: NCT01485003.

Practical Clinical Guidelines for Natalizumab Treatment in Patients With Relapsing Multiple Sclerosis.

Natalizumab (TYSABRI®) was the first high-efficacy monoclonal antibody disease-modifying therapy (DMT) approved as a monotherapy for the treatment of adults with relapsing forms of multiple sclerosis (MS), including clinically isolated syndrome, relapsing-remitting MS, and active secondary progressive MS. Because natalizumab is administered by intravenous infusion, infusion nurses play a key role in the care of natalizumab-treated patients. In the 16 years since approval, substantial data have been gathered on the long-term, real-world effectiveness and safety of natalizumab. This article provides a synopsis of this data, as well as practical information for optimizing patient care. This includes information on strategies to mitigate the risk of progressive multifocal leukoencephalopathy in natalizumab-treated patients, natalizumab use during pregnancy, and use with vaccines. It also includes guidance on the preparation and administration of natalizumab and monitoring of natalizumab-treated patients.

Humoral immune response after Ad26.COV2.S vaccination in patients with multiple sclerosis treated with natalizumab.

The immunomodulatory effects of disease-modifying therapies for multiple sclerosis might affect the immune response to vaccines for severe acute respiratory syndrome coronavirus 2. We analyzed the severe acute respiratory syndrome coronavirus 2-specific antibody response and lymphocyte profile before and after Ad26.COV2.S (Johnson & Johnson) vaccination in natalizumab-treated patients with multiple sclerosis. There was a 72-fold increase in mean anti-severe acute respiratory syndrome coronavirus 2 spike immunoglobulin G levels 4 weeks after vaccination and a 137-fold increase after 6 months. Other immune signals were within normal ranges. Natalizumab-treated patients with multiple sclerosis had a robust immune response to Ad26.COV2.S vaccine, and other immune signals were not significantly affected.

Improvements in Cognitive Processing Speed, Disability, and Patient-Reported Outcomes in Patients with Early Relapsing-Remitting Multiple Sclerosis Treated with Natalizumab: Results of a 4-year, Real-World, Open-Label Study.

BACKGROUND: STRIVE was a prospective, 4-year, multicenter, observational, open-label, single-arm study of natalizumab treatment in anti-JC virus antibody-negative patients with early relapsing-remitting multiple sclerosis (RRMS). OBJECTIVE: Study objectives examined the effects of natalizumab on cognitive processing speed, confirmed disability improvement (CDI), and patient-reported outcomes (PROs). METHODS: Clinical and PRO secondary endpoints were assessed annually over 4 years in STRIVE. The Symbol Digit Modalities Test (SDMT) was used as a measure of cognitive processing speed. PROs were assessed using the Multiple Sclerosis Impact Score (MSIS-29) and the Work Productivity and Activity Impairment Questionnaire (WPAI). RESULTS: At all four annual assessments, the proportion of patients in the intent-to-treat (ITT) population (N = 222) who exhibited clinically meaningful improvement in their SDMT score from baseline (i.e., change ≥ 4 points) ranged from 41.9 to 54.0%. The cumulative probability of CDI at 4 years in patients in the ITT population with a baseline Expanded Disability Status Scale score ≥ 2 (N = 133) was 43.9%. Statistically significant reductions in the mean change from screening in the MSIS-29 physical and psychological scores, indicating improved quality of life, were observed over all 4 years (P ≤ 0.0012 for all). A statistically significant decrease from screening in the impact of MS on regular activities, signifying an improvement in this WPAI measure, was also observed over all 4 years of the study. CONCLUSION: These results further extend our knowledge of the effectiveness, specifically regarding improvements in cognitive processing speed, disability and PROs, of long-term natalizumab treatment in early RRMS patients. CLINICALTRIALS: GOV: NCT01485003 (5 December 2011).

Peginterferon beta-1a concentrations in breast milk of lactating multiple sclerosis patients.

BACKGROUND: Peginterferon beta-1a is an interferon beta-1a formulation that has been pegylated, resulting in a longer half-life than other interferon beta formulations. We examined concentrations of peginterferon beta-1a in breast milk of lactating patients with multiple sclerosis (MS) receiving peginterferon beta-1a as their postpartum disease-modifying therapy. METHODS: After completion of titration to a full dose of peginterferon beta-1a and following a single full dose peginterferon beta-1a injection (125 µg), breast milk samples (≥10 mL) were collected by 5 women on days 1-14 post injection. Peginterferon beta-1a concentrations in breast milk samples were measured by a qualified enzyme-linked immunosorbent assay (detection threshold: 15 pg/mL). Mean and median daily concentrations and median maximum concentration (Cmax), time of Cmax (Tmax), time of last measurable concentration (Tlast), area under the concentration-time curve (AUClast), and relative infant dose (RID) were determined. RESULTS: After receiving a single full dose peginterferon beta-1a injection, the maximum breast milk concentration recorded in an individual patient was 126.2 pg/mL (0.00013 µg/mL) on day 6. The remaining patients all had maximum breast milk concentrations <72 pg/mL. The geometric mean of Cmax was 48.9 pg/mL and the median Tmax and Tlast were 4 and 7 days, respectively. The median AUClast was 210.9 day*pg/mL. Among the 5 study patients, the mean breast milk concentration across all study days was 35.95 pg/mL, with an estimated RID of 0.0054% of the maternal dose. CONCLUSION: Minimal concentrations of peginterferon beta-1a were detected in the breast milk samples. These findings may be useful for clinicians considering postpartum MS treatment options.

Lack of collagen XV impairs peripheral nerve maturation and, when combined with laminin-411 deficiency, leads to basement membrane abnormalities and sensorimotor dysfunction.

Although the Schwann cell basement membrane (BM) is required for normal Schwann cell terminal differentiation, the role of BM-associated collagens in peripheral nerve maturation is poorly understood. Collagen XV is a BM zone component strongly expressed in peripheral nerves, and we show that its absence in mice leads to loosely packed axons in C-fibers and polyaxonal myelination. The simultaneous lack of collagen XV and another peripheral nerve component affecting myelination, laminin α4, leads to severely impaired radial sorting and myelination, and the maturation of the nerve is permanently compromised, contrasting with the slow repair observed in Lama4-/- single knock-out mice. Moreover, the Col15a1-/-;Lama4-/- double knock-out (DKO) mice initially lack C-fibers and, even over 1 year of age have only a few, abnormal C-fibers. The Lama4-/- knock-out results in motor and tactile sensory impairment, which is exacerbated by a simultaneous Col15a1-/- knock-out, whereas sensitivity to heat-induced pain is increased in the DKO mice. Lack of collagen XV results in slower sensory nerve conduction, whereas the Lama4-/- and DKO mice exhibit increased sensory nerve action potentials and decreased compound muscle action potentials; x-ray diffraction revealed less mature myelin in the sciatic nerves of the latter than in controls. Ultrastructural analyses revealed changes in the Schwann cell BM in all three mutants, ranging from severe (DKO) to nearly normal (Col15a1-/-). Collagen XV thus contributes to peripheral nerve maturation and C-fiber formation, and its simultaneous deletion from neural BM zones with laminin α4 leads to a DKO phenotype distinct from those of both single knock-outs.

P0 (protein zero) mutation S34C underlies instability of internodal myelin in S63C mice.

P0 constitutes 50-60% of protein in peripheral nerve myelin and is essential for its structure and stability. Mutations within the P0 gene (MPZ) underlie a variety of hereditary neuropathies. MpzS63C transgenic mice encode a P0 with a serine to cysteine substitution at position 34 in the extracellular domain of mature P0 (P0S34C), associated with the hypomyelinating Déjérine-Sottas syndrome in human. S63C mice develop a dysmyelinating neuropathy, with packing defects in peripheral myelin. Here, we used x-ray diffraction to examine time-dependent packing defects in unfixed myelin. At ∼7 h post-dissection, WT and S63C(+/+) myelin showed native periods (175 Å) with the latter developing at most a few percent swollen myelin, whereas up to ∼50% of S63C(+/-) (mutant P0 on heterozygous P0 null background) or P0(+/-) myelin swelled to periods of ∼205 Å. In the same time frame, S63C(-/-) myelin was stable, remaining swollen at ∼210 Å. Surprisingly, treatment of whole S63C(-/-) nerves with a reducing agent completely reverted swollen arrays to native spacing and also normalized the swollen arrays that had formed in S63C(+/-) myelin, the genotype most closely related to the human disorder. Western blot revealed P0-positive bands at ∼27 and ∼50 kDa, and MALDI-TOF mass spectrometry showed these bands consisted of Ser(34)-containing peptides or P0 dimers having oxidized Cys(34) residues. We propose that P0S34C forms ectopic disulfide bonds in trans between apposed Cys(34) side chains that retard wrapping during myelin formation causing hypomyelination. Moreover, the new bonds create a packing defect by stabilizing swollen membrane arrays that leads to demyelination.

A genetic mouse model of adult-onset, pervasive central nervous system demyelination with robust remyelination.

Adult-onset demyelinating disorders of the central nervous system represent the most common neurological abnormalities in young adults. Nevertheless, our understanding of disease pathogenesis and recovery in demyelinating disorders remains incomplete. To facilitate investigation into these processes, we have developed a new mouse model system that allows for the induction of dipththeria toxin A subunit expression in adult oligodendrocytes, resulting in widespread oligodendrocyte loss and demyelination of the central nervous system. These mice develop severe ataxia and tremor that correlates with impaired axonal conduction in the spinal cord. Strikingly, these animals fully recover from their motor and physiological defects and display extensive oligodendrocyte replenishment and widespread remyelination. This model system demonstrates the robust reparative potential of myelin in the central nervous system and provides a promising model for the quantitative assessment of therapeutic interventions that promote remyelination.

Interferons and Multiple Sclerosis: Lessons from 25 Years of Clinical and Real-World Experience with Intramuscular Interferon Beta-1a (Avonex).

Recombinant interferon (IFN) ß-1b was approved by the US Food and Drug Administration as the first disease-modifying therapy (DMT) for multiple sclerosis (MS) in 1993. Since that time, clinical trials and real-world observational studies have demonstrated the effectiveness of IFN therapies. The pivotal intramuscular IFN ß-1a phase III trial published in 1996 was the first to demonstrate that a DMT could reduce accumulation of sustained disability in MS. Patient adherence to treatment is higher with intramuscular IFN ß-1a, given once weekly, than with subcutaneous formulations requiring multiple injections per week. Moreover, subcutaneous IFN ß-1a is associated with an increased incidence of injection-site reactions and neutralizing antibodies compared with intramuscular administration. In recent years, revisions to MS diagnostic criteria have improved clinicians' ability to identify patients with MS and have promoted the use of magnetic resonance imaging (MRI) for diagnosis and disease monitoring. MRI studies show that treatment with IFN ß-1a, relative to placebo, reduces T2 and gadolinium-enhancing lesions and gray matter atrophy. Since the approval of intramuscular IFN ß-1a, a number of high-efficacy therapies have been approved for MS, though the benefit of these high-efficacy therapies should be balanced against the increased risk of serious adverse events associated with their long-term use. For some subpopulations of patients, including pregnant women, the safety profile of IFN ß formulations may provide a particular benefit. In addition, the antiviral properties of IFNs may indicate potential therapeutic opportunities for IFN ß in reducing the risk of viral infections such as COVID-19.