Ocrelizumab exposure in relapsing-remitting multiple sclerosis: 10-year analysis of the phase 2 randomized clinical trial and its extension

Open-label extension (OLE) studies help inform long-term safety and efficacy of disease-modifying therapies in multiple sclerosis (MS). We report exploratory analyses from a phase 2 trial on the longest follow-up to date of ocrelizumab-treated patients with relapsing-remitting MS (RRMS). The primary treatment period (PTP) comprised four 24-week treatment cycles; participants were randomized to double-blind ocrelizumab (2000 mg or 600 mg), placebo, or interferon β-1a (open label) for one cycle, then dose-blinded ocrelizumab 1000 mg or 600 mg for the remaining cycles. The PTP was followed by consecutive assessed and unassessed treatment-free periods (TFPs) and then the OLE (ocrelizumab 600 mg every 24 weeks). Safety and efficacy were prospectively assessed. Of 220 participants randomized, 183 (84%) completed the PTP. After the TFP, 103 entered OLE (median OLE ocrelizumab exposure 6.5 years). Most common adverse events across all periods were infusion-related reactions. MRI activity, annualized relapse rate, and confirmed disability progression (CDP) rates remained low throughout. During the assessed TFP, there was a trend toward less and later B-cell repletion, and later CDP, for patients randomized to ocrelizumab; MRI activity was observed in 16.3% of patients, the earliest 24 weeks after the last ocrelizumab dose. This is the longest follow-up of ocrelizumab-treated patients with RRMS, with no new safety signals emerging during an observation period from 2008 to 2020. Results reinforce the sustained efficacy of long-term ocrelizumab. Reduced disease activity was maintained following interruption of 6-month dosing cycles, with no evidence of rebound.

Monoclonal Antibodies in the Treatment of Relapsing Multiple Sclerosis: an Overview with Emphasis on Pregnancy, Vaccination, and Risk Management

Monoclonal antibodies have become a mainstay in the treatment of patients with relapsing multiple sclerosis (RMS) and provide some benefit to patients with primary progressive MS. They are highly precise by specifically targeting molecules displayed on cells involved in distinct immune mechanisms of MS pathophysiology. They not only differ in the target antigen they recognize but also by the mode of action that generates their therapeutic effect. Natalizumab, an [Formula: see text]4[Formula: see text]1 integrin antagonist, works via binding to cell surface receptors, blocking the interaction with their ligands and, in that way, preventing the migration of leukocytes across the blood-brain barrier. On the other hand, the anti-CD52 monoclonal antibody alemtuzumab and the anti-CD20 monoclonal antibodies rituximab, ocrelizumab, ofatumumab, and ublituximab work via eliminating selected pathogenic cell populations. However, potential adverse effects may be serious and can necessitate treatment discontinuation. Most importantly, those are the risk for (opportunistic) infections, but also secondary autoimmune diseases or malignancies. Monoclonal antibodies also carry the risk of infusion/injection-related reactions, primarily in early phases of treatment. By careful patient selection and monitoring during therapy, the occurrence of these potentially serious adverse effects can be minimized. Monoclonal antibodies are characterized by a relatively long pharmacologic half-life and pharmacodynamic effects, which provides advantages such as permitting infrequent dosing, but also creates disadvantages regarding vaccination and family planning. This review presents an overview of currently available monoclonal antibodies for the treatment of RMS, including their mechanism of action, efficacy and safety profile. Furthermore, we provide practical recommendations for risk management, vaccination, and family planning.

Myelin water imaging in relapsing multiple sclerosis treated with ocrelizumab and interferon beta-1a

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2-Year change in MS myelin water fraction favored ocrelizumab over interferon.

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Matched healthy controls showed no change in myelin water fraction over 2 years.

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Ocrelizumab appears to protect against demyelination in MS white matter and lesions.

Background

Myelin water imaging is a magnetic resonance imaging (MRI) technique that quantifies myelin damage and repair in multiple sclerosis (MS) via the myelin water fraction (MWF).

Objective

In this substudy of a phase 3 therapeutic trial, OPERA II, MWF was assessed in relapsing MS participants assigned to interferon beta-1a (IFNb-1a) or ocrelizumab (OCR) during a two-year double-blind period (DBP) followed by a two-year open label extension (OLE) with ocrelizumab treatment.

Methods

MWF in normal appearing white matter (NAWM), including both whole brain NAWM and 5 white matter structures, and chronic lesions, was assessed in 29 OCR and 26 IFNb-1a treated participants at weeks 0, 24, 48 and 96 (DBP), and weeks 144 and 192 (OLE), and in white matter for 23 healthy control participants at weeks 0, 48 and 96.

Results

Linear mixed-effects models of data from baseline to week 96 showed a difference in the change in MWF over time favouring ocrelizumab in all NAWM regions. At week 192, lesion MWF was lower for participants originally randomised to IFNb-1a compared to those originally randomised to OCR. Controls showed no change in MWF over 96 weeks in any region.

Conclusion

Ocrelizumab appears to protect against demyelination in MS NAWM and chronic lesions and may allow for a more permissive micro environment for remyelination to occur in focal and diffusely damaged tissue.

Multiple sclerosis plaques may undergo continuous myelin degradation: a cross-sectional study with myelin and axon-related quantitative magnetic resonance imaging metrics

PURPOSE

We hypothesize that myelin is more susceptible to damage over time than axons. We investigated the association between the estimated duration from the onset of multiple sclerosis (MS) plaques and myelin- and axon-related quantitative synthetic magnetic resonance imaging (SyMRI) and neurite orientation dispersion and density imaging (NODDI) metrics.

METHODS

We analyzed 31 patients with MS with 73 newly appeared plaques. Simple linear regression analysis was performed to assess the association between the estimated duration from the onset of plaques and quantitative MRI metrics. These metrics included the myelin volume fraction (MVF), axon volume fraction, and g-ratio in plaque and normal-appearing white matter.

RESULTS

MS plaques with a longer estimated duration from onset were significantly correlated with a lower MVF (slope =  - 0.0070, R² = 0.0970), higher g-ratio (slope = 0.0078, R² = 0.0842) (all P values < 0.05).

CONCLUSION

These results suggested that myelin in plaques undergoes continuous damage, more so than axons. Myelin imaging with SyMRI and NODDI may be useful for the quantitative assessment of temporal changes in MS plaques.

Water content changes in new multiple sclerosis lesions have a minimal effect on the determination of myelin water fraction values

BACKGROUND AND PURPOSE

Myelin water fraction (MWF) is a histopathologically validated in vivo myelin marker. As MWF is the proportion of water with a short T₂ relative to the total water, increases in water from edema and inflammation may confound MWF determination in multiple sclerosis (MS) lesions. Total water content (TWC) measurement enables calculation of absolute myelin water content (MWC) and can be used to distinguish edema/inflammation from demyelination. We assessed what influence changes in total water might have on MWF by calculating MWC values in new MS lesions.

METHODS

3T 32-echo T₂ relaxation data were collected monthly for 6 months from six relapsing-remitting MS participants. TWC was determined and multiplied with MWF images to calculate corrected MWC images. The effect of this water content correction was examined in 20 new lesions by comparing mean MWF and MWC over time.

RESULTS

On average, at lesion first appearance, lesion TWC increased by 6.4% (p = .003; range: -1% to +21%), MWF decreased by 24% (p = .006; range: -70% to +12%), and MWC decreased by 20% (p = .026; range: -68% to +21%), relative to prelesion values. Average TWC in lesions then gradually decreased, whereas MWF and MWC remained low. The shape of the MWF and MWC lesion evolution curves was nearly identical, differing only by an offset.

CONCLUSION

MWF mirrors MWC and is able to monitor myelin in new lesions. Even after taking into account water content increases, MWC still decreased at lesion first appearance attributed to demyelination.

Efficacy and safety of alemtuzumab over 6 years: final results of the 4-year CARE-MS extension trial

BACKGROUND

In the 2-year CARE-MS I and II trials, alemtuzumab 12 mg administered on 5 consecutive days at core study baseline and on 3 consecutive days 12 months later significantly improved outcomes versus subcutaneous interferon beta-1a (SC IFNB-1a) in relapsing-remitting multiple sclerosis patients. Here, we present the final 6-year CARE-MS extension trial results (CAMMS03409), and compare outcomes over 6 years in patients randomized to both treatment groups at core study baseline.

METHODS

Over a 4-year extension, alemtuzumab patients (alemtuzumab-only) received as-needed additional alemtuzumab (⩾12 months apart) for disease activity after course 2. SC IFNB-1a patients who entered the extension discontinued SC IFNB-1a and received 2 alemtuzumab 12 mg courses (IFN-alemtuzumab), followed by additional, as-needed, alemtuzumab.

RESULTS

Through year 6, 63% of CARE-MS I and 50% of CARE-MS II alemtuzumab-only patients received neither additional alemtuzumab nor other disease-modifying therapy, with lasting suppression of disease activity, improved disability, and slowing of brain volume loss (BVL). In CARE-MS I patients (treatment-naive; less disability; shorter disease duration), disease activity and BVL were significantly reduced in IFN-alemtuzumab patients, similar to alemtuzumab-only patients at year 6. Among CARE-MS II patients (inadequate response to prior treatment; more disability; longer disease duration), alemtuzumab significantly improved clinical and magnetic resonance imaging outcomes, including BVL, in IFN-alemtuzumab patients; however, disability outcomes were less favorable versus alemtuzumab-only patients. Safety profiles, including infections and autoimmunities, following alemtuzumab were similar between treatment groups.

CONCLUSION

This study demonstrates the high efficacy of alemtuzumab over 6 years, with a similar safety profile between treatment groups.

CLINICALTRIALSGOV IDENTIFIERS

NCT00530348; NCT00548405; NCT00930553.

Multimodal MRI Response to Fingolimod in Multiple Sclerosis: A Nonrandomized, Single Arm, Observational Study

BACKGROUND AND PURPOSE

Fingolimod has a favorable effect on conventional MRI measures; however, its neuroprotective effect is not clear. We aim to investigate changes of conventional and advanced MRI measures in lesions and normal-appearing white matter (NAWM) over 2 years in fingolimod-treated patients.

METHODS

Fifty relapsing-remitting multiple sclerosis patients and 27 healthy controls were enrolled in the study and underwent baseline, 1-year, and 2-year 3T MRI scans. T2 lesion volume, whole brain volume, cortical gray matter volume, white matter volume, corpus callosum area, percentage brain volume change (PBVC), Expanded Disability Status Scale, gadolinium-enhancing lesions, PBVC, magnetization transfer ratio (MTR), and diffusion tensor imaging metrics (fractional anisotropy [FA] and median diffusivity [MD]) in lesions and NAWM were calculated. Longitudinal changes were examined using one-way repeated measures ANOVA. Bonferroni correction for multiple testing was used when appropriate.

RESULTS

Conventional MRI measures were unchanged in both groups. Lesion MTR increased significantly (P < .001), but NAWM-MTR remained unchanged. Lesion FA improved significantly in year 1 (P = .003) and over the study duration (P = .05). Lesion MD changed significantly from baseline to year 1 (P < .001) and remained stable over 2 years. NAWM-FA was significant from baseline to year 1 (P = .002) and from baseline to year 2 (P < .001). NAWM-MD was significant only from baseline to year 1 (P = .001).

CONCLUSIONS

These findings suggest a possible neuroreparative effect of fingolimod on the MS lesions and NAWM. Larger and longer randomized studies are required to confirm these results.

Magnetic resonance spectroscopy of the normal appearing grey matter in the posterior cingulate gyrus in the prognosis and monitoring of disease activity in MS patients treated with interferon-β in a 3-year follow-up

Several predictors of non-response to interferon-β (IFN-β) treatment have been proposed. The aim of the study was to identify metabolite changes in the normal-appearing cortex of the posterior cingulate gyrus (PCG) using MRS (magnetic resonance spectroscopy) and to investigate their usefulness in prognosis of NEDA (no evidence of disease activity) in the 3-year follow-up and in monitoring treatment effects during IFN-β therapy in the parallel period of time in multiple sclerosis (MS) patients. Forty-one relapsing-remitting MS patients and 41 sex- and age-matched healthy subjects underwent routine MRI protocol with MRS sequence with the use of a 1.5 T magnet. A single voxel size of 2x2x2cm was inserted in the cortex of PCG region. Associations between baseline metabolic ratios, conventional MRI findings, demographic and clinical factors, and NEDA status were evaluated using logistic, Cox, and multinomial logistic regression models. MS patients in the initial scan showed a statistically significant decline in NAA/Cr ratio (p < 0.0001) and an increase in Cho/Cr ratio (p = 0.016) compared to the control group. None of the MRS parameters predicted NEDA maintenance or the time to loss of NEDA. In treatment monitoring only an improvement in the combination of NAA/Cr + Cho/Cr ratio between the 1st and 2nd year of treatment was connected with a 6.27-fold chance (p = 0.025) of having simultaneous NEDA maintenance. To conclude, metabolite alterations in the PCG region did not predict NEDA maintenance, but they seem to be useful in treatment monitoring.

Repopulation of T, B, and NK cells following alemtuzumab treatment in relapsing-remitting multiple sclerosis

OBJECTIVE

To characterize long-term repopulation of peripheral immune cells following alemtuzumab-induced lymphopenia in relapsing-remitting MS (RRMS), with a focus on regulatory cell types, and to explore associations with clinical outcome measures.

METHODS

The project was designed as a multicenter add-on longitudinal mechanistic study for RRMS patients enrolled in CARE-MS II, CARE-MS II extension at the University of Southern California and Stanford University, and an investigator-initiated study conducted at the Universities of British Columbia and Chicago. Methods involved collection of blood at baseline, prior to alemtuzumab administration, and at months 5, 11, 17, 23, 36, and 48 post-treatment. T cell, B cell, and natural killer (NK) cell subsets, chemokine receptor expression in T cells, in vitro cytokine secretion patterns, and regulatory T cell (Treg) function were assessed. Clinical outcomes, including expanded disability status score (EDSS), relapses, conventional magnetic resonance imaging (MRI) measures, and incidents of secondary autoimmunity were tracked.

RESULTS

Variable shifts in lymphocyte populations occurred over time in favor of CD4+ T cells, B cells, and NK cells with surface phenotypes characteristic of regulatory subsets, accompanied by reduced ratios of effector to regulatory cell types. Evidence of increased Treg competence was observed after each treatment course. CD4+ and CD8+ T cells that express CXCR3 and CCR5 and CD8+ T cells that express CDR3 and CCR4 were also enriched after treatment, indicating heightened trafficking potential in activated T cells. Patterns of repopulation were not associated with measures of clinical efficacy or secondary autoimmunity, but exploratory analyses using a random generalized estimating equation (GEE) Poisson model provide preliminary evidence of associations between pro-inflammatory cell types and increased risk for gadolinium (Gd+) enhancing lesions, while regulatory subsets were associated with reduced risk. In addition, the risk for T2 lesions correlated with increases in CD3+CD8+CXCR3+ cells.

CONCLUSIONS

Lymphocyte repopulation after alemtuzumab treatment favors regulatory subsets in the T cell, B cell, and NK cell compartments. Clinical efficacy may reflect the sum of interactions among them, leading to control of potentially pathogenic effector cell types. Several immune measures were identified as possible biomarkers of lesion activity. Future studies are necessary to more precisely define regulatory and effector subsets and their contributions to clinical efficacy and risk for secondary autoimmunity in alemtuzumab-treated patients, and to reveal new insights into mechanisms of immunopathogenesis in MS.

TRIAL REGISTRATION

Parent trials for this study are registered with ClinicalTrials.gov: CARE-MS II: NCT00548405, CARE-MS II extension: NCT00930553 and ISS: NCT01307332.

Validation of Rapid Magnetic Resonance Myelin Imaging in Multiple Sclerosis

OBJECTIVE

Magnetic resonance imaging (MRI) is essential for multiple sclerosis diagnostics but is conventionally not specific to demyelination. Myelin imaging is often hampered by long scanning times, complex postprocessing, or lack of clinical approval. This study aimed to assess the specificity, robustness, and clinical value of Rapid Estimation of Myelin for Diagnostic Imaging, a new myelin imaging technique based on time-efficient simultaneous T₁ /T₂ relaxometry and proton density mapping in multiple sclerosis.

METHODS

Rapid myelin imaging was applied using 3T MRI ex vivo in 3 multiple sclerosis brain samples and in vivo in a prospective cohort of 71 multiple sclerosis patients and 21 age/sex-matched healthy controls, with scan-rescan repeatability in a subcohort. Disability in patients was assessed by the Expanded Disability Status Scale and the Symbol Digit Modalities Test at baseline and 2-year follow-up.

RESULTS

Rapid myelin imaging correlated with myelin-related stains (proteolipid protein immunostaining and Luxol fast blue) and demonstrated good precision. Multiple sclerosis patients had, relative to controls, lower normalized whole-brain and normal-appearing white matter myelin fractions, which correlated with baseline cognitive and physical disability. Longitudinally, these myelin fractions correlated with follow-up physical disability, even with correction for baseline disability.

INTERPRETATION

Rapid Estimation of Myelin for Diagnostic Imaging provides robust myelin quantification that detects diffuse demyelination in normal-appearing tissue in multiple sclerosis, which is associated with both cognitive and clinical disability. Because the technique is fast, with automatic postprocessing and US Food and Drug Administration/CE clinical approval, it can be a clinically feasible biomarker that may be suitable to monitor myelin dynamics and evaluate treatments aiming at remyelination. ANN NEUROL 2020;87:710-724.

So You Want to Image Myelin Using MRI: An Overview and Practical Guide for Myelin Water Imaging

Myelin water imaging (MWI) is an MRI imaging biomarker for myelin. This method can generate an in vivo whole-brain myelin water fraction map in approximately 10 minutes. It has been applied in various applications including neurodegenerative disease, neurodevelopmental, and neuroplasticity studies. In this review we start with a brief introduction of myelin biology and discuss the contributions of myelin in conventional MRI contrasts. Then the MRI properties of myelin water and four different MWI methods, which are categorized as T₂ -, T₂ *-, T₁ -, and steady-state-based MWI, are summarized. After that, we cover more practical issues such as availability, interpretation, and validation of these methods. To illustrate the utility of MWI as a clinical research tool, MWI studies for two diseases, multiple sclerosis and neuromyelitis optica, are introduced. Additional topics about imaging myelin in gray matter and non-MWI methods for myelin imaging are also included. Although technical and physiological limitations exist, MWI is a potent surrogate biomarker of myelin that carries valuable and useful information of myelin. Evidence Level: 5 Technical Efficacy: 1 J. MAGN. RESON. IMAGING 2021;53:360-373.

Reproducibility, reliability and variability of FA and MD in the older healthy population: A test-retest multiparametric analysis

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In older healthy subjects, FA and MD show overall good test-retest reliability & reproducibility.

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MD is sistematically more reproducible than FA across the entire brain anatomy.

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FA is more reliable than MD in subcortical white matter regions.

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In high reliability & low reproducibility regions, variability between subjects is high and statistical power is low.

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In low reliability & high reproducibility regions, variability between subjects is low and statistical power is high.

Advances in brain imaging in multiple sclerosis

Brain imaging is increasingly used to support clinicians in diagnosing multiple sclerosis (MS) and monitoring its progression. However, the role of magnetic resonance imaging (MRI) in MS goes far beyond its clinical application. Indeed, advanced imaging techniques have helped to detect different components of MS pathogenesis in vivo, which is now considered a heterogeneous process characterized by widespread damage of the central nervous system, rather than multifocal demyelination of white matter. Recently, MRI biomarkers more sensitive to disease activity than clinical disability outcome measures, have been used to monitor response to anti-inflammatory agents in patients with relapsing-remitting MS. Similarly, MRI markers of neurodegeneration exhibit the potential as primary and secondary outcomes in clinical trials for progressive phenotypes. This review will summarize recent advances in brain neuroimaging in MS from the research setting to clinical applications.

Application of advanced MRI techniques to monitor pharmacologic and rehabilitative treatment in multiple sclerosis: current status and future perspectives

Introduction: Advances in magnetic resonance imaging (MRI) technology and analyses are improving our understanding of the pathophysiology of multiple sclerosis (MS). Due to their ability to grade the presence of irreversible tissue loss, microstructural tissue abnormalities, metabolic changes and functional plasticity, the application of these techniques is also expanding our knowledge on the efficacy and mechanisms of action of different pharmacological and rehabilitative treatments. Areas covered: This review discusses recent findings derived from the application of advanced MRI techniques to evaluate the structural and functional substrates underlying the effects of pharmacologic and rehabilitative treatments in patients with MS. Current applications as outcome in clinical trials and observational studies, their interpretation and possible pitfalls in their use are discussed. Finally, how these techniques could evolve in the future to improve monitoring of disease progression and treatment response is examined. Expert commentary: The number of treatments currently available for MS is increasing. The application of advanced MRI techniques is providing reliable and specific measures to better understand the targets of different treatments, including neuroprotection, tissue repair, and brain plasticity. This is a fundamental progress to move toward personalized medicine and individual treatment selection.

Myelin water imaging to detect demyelination and remyelination and its validation in pathology

Damage to myelin is a key feature of multiple sclerosis (MS) pathology. Magnetic resonance imaging (MRI) has revolutionized our ability to detect and monitor MS pathology in vivo. Proton density, T1 and T2 can provide qualitative contrast weightings that yield superb in vivo visualization of central nervous system tissue and have proved invaluable as diagnostic and patient management tools in MS. However, standard clinical MR methods are not specific to the types of tissue damage they visualize, and they cannot detect subtle abnormalities in tissue that appears otherwise normal on conventional MRIs. Myelin water imaging is an MR method that provides in vivo measurement of myelin. Histological validation work in both human brain and spinal cord tissue demonstrates a strong correlation between myelin water and staining for myelin, validating myelin water as a marker for myelin. Myelin water varies throughout the brain and spinal cord in healthy controls, and shows good intra- and inter-site reproducibility. MS plaques show variably decreased myelin water fraction, with older lesions demonstrating the greatest myelin loss. Longitudinal study of myelin water can provide insights into the dynamics of demyelination and remyelination in plaques. Normal appearing brain and spinal cord tissues show reduced myelin water, an abnormality which becomes progressively more evident over a timescale of years. Diffusely abnormal white matter, which is evident in 20%-25% of MS patients, also shows reduced myelin water both in vivo and postmortem, and appears to originate from a primary lipid abnormality with relative preservation of myelin proteins. Active research is ongoing in the quest to refine our ability to image myelin and its perturbations in MS and other disorders of the myelin sheath.