Krzysztof Selmaj

Background and objectives: To investigate the total circulating exosome transcriptome in animal models of two different CNS pathologic conditions, autoimmune demyelination and traumatic brain injury (TBI). Methods: Next generation sequencing (NGS) was used to define the global RNA profile of blood exosomes in the MOG-induced EAE model of autoimmune demyelination and TBI mice model. We analyzed 5 million reads per sample, including a detailed analysis of microRNAs (miRNAs) differentially expressed in EAE versus control mice and versus TBI model. Results: Exosomal RNA NGS revealed 10 different classes of transcripts including miRNA. MiRNA numbers from EAE and TBI mice showed trend to be lower versus control mice. The differentially expressed miRNAs were found in all three sequential EAE time points: early stage post mice immunization (EAEp), peak of disease (EAEa) and recovery (EAEl). The differential expression pattern of miRNA in EAE versus TBI correlated with their involvement in activation or inhibition of immune response. In the early stage of EAE miRNA-335-5p and miRNA-411-5p were upregulated versus TBI. At the peak of disease six miRNAs were most upregulated, miRNA-27a-3p, miRNA-141-3p, miRNA27b-3p, miRNA-195a-5p, miRNA21a-5p and miRNA-99a-5p. The six most upregulated miRNA at the recovery time point of EAE, miRNA-27b-3p, miRNA 141-3p, miRNA 27a-3p, miRNA-127-3p, miRNA-429-3p and let-7b-5p were associated with inhibition of immune response and enhancement of immunoregulation. Interestingly, it was found that similar pattern of downregulated miRNAs versus TBI were present at all three of EAE time points. Bioinformatic analysis of protein genes targeted by the most differentially expressed miRNAs revealed a numbers of proteins involved in neuroinflammation both in EAE and TBI models. In the early phase of EAE, three protein transcripts, Hdac9, Syt7 and NT5c2 serve as an epigenetic switch controlling T cell fate and cytokine production. In recovery of EAE RoRb, a member of ROR nuclear receptor family involved in Th17 cell differentiation was inhibited. Discussion: These data indicate that different type of CNS pathology, autoimmune demyelination versus TBI is associated with different pattern of miRNA expression in circulating exosomes which may suggest their differential role in these two CNS pathologies.

B-cell depletion with anti-CD20 monoclonal antibody (mAb) represents a novel and highly effective treatment for patients with multiple sclerosis. Although all approved anti-CD-20 mAbs for multiple sclerosis (MS) treatment, ocrelizumab, ofatumumab, and ublituximab, target the same molecule on the B-cell surface, some differences in their molecular structure translate into important distinctions in their mechanisms of B-cell depletion. Differences between an antibody-dependent cell-mediated cytotoxicity (ADCC) versus a complement-dependent cytotoxicity (CDC) in anti-CD20 mAbs mechanism of action correspond to deeper B-cell depletion as well as better tolerability. Glycoengineering of the Fc portion of ublituximab with reduced fucosylation enhances affinity to Fc gamma receptor IIIa (FcγRIIIa) on natural killer (NK) cells. This molecular modification of ublituximab exhibits significantly higher ADCC activity in relation to CDC in B-cell depletion mechanisms. In addition, glycoengineering of ublituximab reduces the importance of the FcγRIIIa 158V/F polymorphism, which influences the effectiveness of B-cell depletion. In the ULTIMATE I and II studies, ublituximab showed a significant reduction in annual relapse rate versus teriflunomide in relapsing MS patients and strikingly reduced active and new/enlarging MRI lesions. Ublituximab also showed efficacy on the disease progression and increased disability improvement in the extended 5-year observation study. The advantage of ublituximab also correlates with good tolerability and reduced infusion-related reactions. Ublituximab infusion, 1 h, is significantly shorter in comparison to other intravenous (IV) preparations of anti-CD20 mAbs. Thus, ublituximab provides better convenience to MS patients as well as saves the time of healthcare providers.

Objective: Return of disease activity is expected when patients discontinue disease‐modifying therapy (DMT) for multiple sclerosis (MS). Some MS DMTs are associated with higher‐than‐expected disease activity (rebound) after discontinuation. This exploratory analysis assessed disease activity and risk of rebound after ozanimod discontinuation. Methods: DAYBREAK (NCT02576717; October 2015–April 2023) was a single‐arm, open‐label extension trial of ozanimod 0.92 mg/d in participants with relapsing MS who completed phase 1–3 ozanimod trials. Two protocol amendments increased the required safety follow‐up from an initial 28 days to 75 and then 90 days. Confirmed post‐treatment relapses were characterized. Results: Of 2494 participants, 1679 participants had ≥ 1 day of follow‐up and did not initiate commercial ozanimod in ≤ 14 days of exiting the trial; 30.6% had ≤ 60 days of post‐treatment follow‐up. Fifty‐five participants (3.3%) had known post‐treatment relapse. Fifty‐four were not taking an MS DMT when they relapsed; one relapsed soon after starting fingolimod. Relapses were associated with Expanded Disability Status Scale (EDSS) score increases of 0–3 points (median 1 point); the participant with the 3‐point increase had a moderate relapse and complete recovery in 23 days. Forty‐two participants (76.4%) fully recovered, 11 (20.0%) partially recovered, and 2 (3.6%) did not recover. Only one (1.8%) relapse was considered severe by the investigator: EDSS increased from 7.5 to 8.0, and the participant partially recovered within 36 days. Interpretation: Most participants did not relapse within 90 days following ozanimod discontinuation. Post‐treatment relapse cases suggestive of a rebound effect were not observed.

SYNE1 ataxia is a rare representative of autosomal recessive hereditary cerebellar ataxias (ARCAs). It was originally described in the Beauce region of Quebec as a pure cerebellar form of ataxia. Later, more complex phenotypes with a wide range of extra-cerebellar neurological and non-neurological dysfunctions were discovered in other geographical locations. SYNE1 deficiency was predominantly linked to nonsense and frameshift variants; however, missense variants in the gene SYNE1 have also been described as causative for this type of ataxia. We here describe a case of an adult female patient with a phenotype of progressive ataxic features over 15 years, combined with spastic paraparesis. Non-neurological symptoms were not present. The family history was negative, and the case was classified as sporadic. However, the parents of the patient were related to both grandmothers, being cousins. DNA was sequenced using the Illumina HiSeq/Nova Seq system, and the variant c.23413A>G; p.Arg7805Gly in the gene SYNE1 was found in a homozygous state (NM_033071.4; NP_149062.2). This missense variant has not been described in the literature and is not listed in the relevant databases. This homozygous substitution resulted in an amino acid change, arginine for glycine, in a highly conserved region of the SYNE1 gene. According to ACMG/ACGS guidelines, the criteria PM2+PM3_supporting+PP3 were applied, which classified the substitution c.23413A>G; p.Arg7805Gly as “a variant of uncertain significance.” The calculated effect of this substitution is mostly pathogenic based on several in silico prediction programs. The presence of spastic paraparesis grades this case as an ataxic complex syndrome. This is the first SYNE1 ataxia patient of Polish origin with a novel missense variant described with full clinical and MRI data.

Introduction Cognitive impairment can affect people with multiple sclerosis (MS) at all stages, negatively impacting their work performance and quality of life. This study aimed to report the cognitive function and employment status data for participants with highly active relapsing MS (RMS) treated with cladribine tablets (CladT) during the 2-year, prospective, open-label, exploratory, single-arm, multicentre, phase IV CLARIFY-MS study. Methods In this post hoc analysis, changes in cognitive function at month (M)12 and M24 (vs baseline) were measured using the Brief International Cognitive Assessment for MS (BICAMS) battery. Additional analyses were conducted to assess clinically meaningful 4- and 8-point changes in Symbol Digit Modalities Test (SDMT) scores. The employment status of participants was determined through a survey at baseline and M24. Results BICAMS parameter scores remained stable over 2 years in CladT-treated participants. As determined by a 4- and 8-point change, a high proportion of participants had increased or stable SDMT scores at M24 versus baseline. The mean annualised percentage brain volume change (PBVC) in participants was low. No correlation was found between changes in BICAMS parameter scores and annualised PBVC. Furthermore, no major differences in the employment status of participants were observed over 2 years, with > 40% of participants being in full-time employment during the study. Conclusions Most CLARIFY-MS participants had increased or stable information processing speed at M24 (vs baseline), as determined using clinically meaningful 4- and 8-point changes in SDMT scores. Overall, the cognitive function and employment status of CladT-treated participants with highly active RMS remained stable over 2 years. Trial Registry Details URL: https://clinicaltrials.gov/ct2/show/NCT03369665; ClinicalTrials.gov Identifier: NCT03369665.

Anti-CD20 monoclonal antibodies represent a particularly important class of drugs in the treatment of multiple sclerosis. This results from the discovery of the instrumental function of B cells in the initiation of multiple sclerosis autoimmunity, as well as their role in the protraction of the disease process. Ofatumumab is the first fully humanised anti-CD20 monoclonal antibody. Phase 2 and 3 trials demonstrated high efficacy of ofatumumab in a population of patients with the relapsing-remitting and relapsing form of multiple sclerosis. Ofatumumab very efficiently decreased number of relapses. In comparison to placebo or the active comparator, teriflunomide, the annual relapse rate was reduced by more than 50%. Even more spectacular efficacy was demonstrated in the reduction of active magnetic resonance imaging lesions. Compared to teriflunomide, the number of gadolinium-enhancing lesions was reduced by more than 90%. In the pooled population from both phase 3 studies, ofatumumab also reduced the risk for disability progression. These data allow for the classification of ofatumumab in the group of high-efficacy treatment agents for multiple sclerosis. In a protracted disorder like multiple sclerosis, it is critically important to understand long-term efficacy and safety. To date, six-year data are available on ofatumumab treatment in relapsing-remitting multiple sclerosis. These results confirm the high efficacy of ofatumumab in long-term treatment in the population of relapsing-remitting multiple sclerosis patients.

Background: Ozanimod, a selective, oral sphingosine 1-phosphate receptor 1 and 5 modulator, is approved in multiple countries for adults with relapsing forms of multiple sclerosis (RMS). Objective: To characterize the long-term safety and efficacy of ozanimod. Methods: Participants were eligible for an open-label extension study of ozanimod 0.92 mg/d (DAYBREAK) if they completed a phase 1–3 RMS ozanimod ‘parent’ trial. DAYBREAK began 16 October 2015, and ended 5 January 2023. Results: DAYBREAK included 2494 participants with a mean of 60.9 (range 0.03‒81.5) months of ozanimod exposure. During DAYBREAK, 2219 participants (89.0%) had treatment-emergent adverse events (TEAEs), 381 (15.3%) had a serious TEAE and 98 (3.9%) discontinued treatment due to TEAEs. Serious infections (4.3%), herpes zoster infections (2.0%), confirmed macular oedema cases (0.2%), and cardiac TEAEs (4.1 %) were infrequent. Adjusted annualized relapse rate was 0.098 (95% confidence interval, 0.082‒0.117). In total, 69.1% of participants remained relapse-free and 84.8% were free from 6-month confirmed disability progression at DAYBREAK completion. Adjusted mean numbers of new/enlarging T2 lesions/scan and gadolinium-enhancing lesions were low and remained relatively stable. Conclusions: Long-term ozanimod treatment had a favourable safety and tolerability profile and provided sustained control of clinical and MRI disease activity in participants with RMS. Registries: ClinicalTrials.gov ID: NCT02576717; EudraCT: 2015-002500-91.

Background: Multiple sclerosis (MS) pathology is characterized by acute and chronic inflammation, demyelination, axonal injury, and neurodegeneration. After decades of research into MS-related degeneration, recent efforts have shifted toward recovery and the prevention of further damage. A key area of focus is the remyelination process, where researchers are studying the effects of pharmacotherapy on myelin repair mechanisms. Multiple compounds are being tested for their potential to foster remyelination in different clinical settings through the application of less or more complex techniques to assess their efficacy. Objective: To review current methods and biomarkers to track myelin regeneration and recovery over time in people with MS (PwMS), with potential implications for promyelinating drug testing. Methods: Narrative review, based on a selection of PubMed articles discussing techniques to measure in vivo myelin repair and functional recovery in PwMS. Results: Non-invasive tools, such as structural Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET), are being implemented to track myelin repair, while other techniques like evoked potentials, functional MRI, and digital markers allow the assessment of functional recovery. These methods, alone or in combination, have been employed to obtain precise biomarkers of remyelination and recovery in various clinical trials on MS. Conclusions: Combining different techniques to identify myelin restoration in MS could yield novel biomarkers, enhancing the accuracy of clinical trial outcomes for remyelinating therapies in PwMS.