Bruton's Tyrosine Kinase Inhibition in Multiple Sclerosis

Infiltration by monocytes of the central nervous system and its role in multiple sclerosis: reflections on therapeutic strategies

Mononuclear macrophage infiltration in the central nervous system is a prominent feature of neuroinflammation. Recent studies on the pathogenesis and progression of multiple sclerosis have highlighted the multiple roles of mononuclear macrophages in the neuroinflammatory process. Monocytes play a significant role in neuroinflammation, and managing neuroinflammation by manipulating peripheral monocytes stands out as an effective strategy for the treatment of multiple sclerosis, leading to improved patient outcomes. This review outlines the steps involved in the entry of myeloid monocytes into the central nervous system that are targets for effective intervention: the activation of bone marrow hematopoiesis, migration of monocytes in the blood, and penetration of the blood-brain barrier by monocytes. Finally, we summarize the different monocyte subpopulations and their effects on the central nervous system based on phenotypic differences. As activated microglia resemble monocyte-derived macrophages, it is important to accurately identify the role of monocyte-derived macrophages in disease. Depending on the roles played by monocyte-derived macrophages at different stages of the disease, several of these processes can be interrupted to limit neuroinflammation and improve patient prognosis. Here, we discuss possible strategies to target monocytes in neurological diseases, focusing on three key aspects of monocyte infiltration into the central nervous system, to provide new ideas for the treatment of neurodegenerative diseases.

The relation between BTK expression and iron accumulation of myeloid cells in multiple sclerosis

Activation of Bruton's tyrosine kinase (BTK) has been shown to play a crucial role in the proinflammatory response of B cells and myeloid cells upon engagement with B cell, Fc, Toll-like receptor, and distinct chemokine receptors. Previous reports suggest BTK actively contributes to the pathogenesis of multiple sclerosis (MS). The BTK inhibitor Evobrutinib has been shown to reduce the numbers of gadolinium-enhancing lesions and relapses in relapsing-remitting MS patients. In vitro, BTK inhibition resulted in reduced phagocytic activity and modulated BTK-dependent inflammatory signaling of microglia and macrophages. Here, we investigated the protein expression of BTK and CD68 as well as iron accumulation in postmortem control (n = 10) and MS (n = 23) brain tissue, focusing on microglia and macrophages. MS cases encompassed active, chronic active, and inactive lesions. BTK+ and iron+ cells positively correlated across all regions of interests and, along with CD68, revealed highest numbers in the center of active and at the rim of chronic active lesions. We then studied the effect of BTK inhibition in the human immortalized microglia-like HMC3 cell line in vitro. In particular, we loaded HMC3 cells with iron-dextran and subsequently administered the BTK inhibitor Evobrutinib. Iron treatment alone induced a proinflammatory phenotype and increased the expression of iron importers as well as the intracellular iron storage protein ferritin light chain (FTL). BTK inhibition of iron-laden cells dampened the expression of microglia-related inflammatory genes as well as iron-importers, whereas the iron-exporter ferroportin was upregulated. Our data suggest that BTK inhibition not only dampens the proinflammatory response but also reduces iron import and storage in activated microglia and macrophages with possible implications on microglial iron accumulation in chronic active lesions in MS.

Predicted Expenditure for Prescription Drugs for Multiple Sclerosis in the Italian Market Between 2023 and 2028: Results of the Oracle Project

INTRODUCTION

Multiple sclerosis (MS) is a chronic neurodegenerative disease that leads to impaired cognitive function and accumulation of disability, with significant socioeconomic burden. Serious unmet need in the context of managing MS has given rise to ongoing research efforts, leading to the launch of new drugs planned for the near future, and subsequent concerns about the sustainability of healthcare systems. This study assessed the changes in the Italian MS market and their impact on the expenditures of the Italian National Healthcare Service between 2023 and 2028.

METHODS

A horizon-scanning model was developed to estimate annual expenditure from 2023 to 2028. Annual expenditure for MS was calculated by combining the number of patients treated with each product (clinical inputs) and the yearly costs of therapy (economic inputs). Baseline inputs (2020-2022) were collected from IQVIA® real-world data, while input estimation for the 5-year forecast was integrated with analog analyses and the insights of clinicians and former payers.

RESULTS

The number of equivalent patients treated in 2028 in Italy was estimated at around 67,000, with an increase of 10% versus 2022. In terms of treatment pattern evolution, first-line treatments are expected to reduce their shares from 47% in 2022 to 27% in 2028, and Bruton tyrosine kinase inhibitors are expected to reach 23% of patient shares. Overall, expenditure for MS is estimated to decrease from €721 million in 2022 to €551 million in 2028, mainly due to losses of exclusivity and renegotiation of drug prices.

CONCLUSION

Despite the increase in the number of patients treated for MS and the launch of new molecules that will reach high market penetration, the model confirmed sustainability for the Italian National Healthcare Service.

Novel and Emerging Treatments to Target Pathophysiological Mechanisms in Various Phenotypes of Multiple Sclerosis

The objective is to comprehensively review novel pharmacotherapies used in multiple sclerosis (MS) and the possibilities they may carry for therapeutic improvement. Specifically, we discuss pathophysiological mechanisms worth targeting in MS, ranging from well known targets, such as autoinflammation and demyelination, to more novel and advanced targets, such as neuroaxonal damage and repair. To set the stage, a brief overview of clinical MS phenotypes is provided, followed by a comprehensive recapitulation of both clinical and paraclinical outcomes available to assess the effectiveness of treatments in achieving these targets. Finally, we discuss various promising novel and emerging treatments, including their respective hypothesized modes of action and currently available evidence from clinical trials. SIGNIFICANCE STATEMENT: This comprehensive review discusses pathophysiological mechanisms worth targeting in multiple sclerosis. Various promising novel and emerging treatments, including their respective hypothesized modes of action and currently available evidence from clinical trials, are reviewed.

Bruton tyrosine kinase inhibitors in multiple sclerosis: evidence and expectations

PURPOSE OF REVIEW

Despite availability of high-efficacy therapies for multiple sclerosis (MS), many patients experience significant disability worsening due to limited effects of currently available drugs on central nervous system (CNS)-compartmentalized inflammation. Bruton tyrosine kinase (BTK) is an intracellular signaling molecule involved in regulation of maturation, survival, migration, and activation of B cells and microglia, which are central players in the immunopathogenesis of progressive MS. Therefore, CNS-penetrant BTK inhibitors may better prevent disease progression by targeting immune cells on both sides of the blood-brain barrier. This review gives an overview on the preliminary results of clinical trials.

RECENT FINDINGS

Currently, the efficacy and safety of six BTK inhibitors are being evaluated in clinical trials in patients with relapsing and progressive MS. Evobrutinib, tolebrutinib and fenebrutinib have shown efficacy and safety in relapsing MS in phase 2 studies, and evobrutinib and tolebrutinib in their extension studies up to 3-5 years. However, evobrutinib failed to distinguish itself from the comparator drug teriflunomide in reduction of relapse rate (primary end point) in two phase 3 studies in relapsing MS.

SUMMARY

Inhibition of BTK has emerged as a promising therapeutic approach to target the CNS-compartmentalized inflammation. Results from phase 3 clinical trials will shed light on differences in efficacy and safety of BTK inhibitors and its potential role in the future MS landscape.

Inhibitors of Bruton's tyrosine kinase as emerging therapeutic strategy in autoimmune diseases

Bruton's tyrosine kinase (BTK) is a cytoplasmic, non-receptor signal transducer, initially identified as an essential signaling molecule for B cells, with genetic mutations resulting in a disorder characterized by disturbed B cell and antibody development. Subsequent research revealed the critical role of BTK in the functionality of monocytes, macrophages and neutrophils. Various immune cells, among which B cells and neutrophils, rely on BTK activity for diverse signaling pathways downstream of multiple receptors, which makes this kinase an ideal target to treat hematological malignancies and autoimmune diseases. First-generation BTK inhibitors are already on the market to treat hematological disorders. It has been demonstrated that B cells and myeloid cells play a significant role in the pathogenesis of different autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus and primary Sjögren's syndrome. Consequently, second-generation BTK inhibitors are currently being developed to treat these disorders. Despite the acknowledged involvement of BTK in various cell types, the focus on B cells often overshadows its impact on innate immune cells. Among these cell types, neutrophils are often underestimated in the pathogenesis of autoimmune diseases. In this narrative review, the function of BTK in different immune cell subsets is discussed, after which an overview is provided of different upcoming BTK inhibitors tested for treatment of autoimmune diseases. Special attention is paid to BTK inhibition and its effect on neutrophil biology.

Clinical and Treatment Considerations for the Pediatric and Aging Patients with Multiple Sclerosis

Chronologic aging is associated with multiple pathologic and immunologic changes that impact the clinical course of multiple sclerosis (MS). Clinical phenotypes evolve across the lifespan, from a highly inflammatory course in the very young to a predominantly neurodegenerative phenotype in older patients. Thus, unique clinical considerations arise for the diagnosis and management of the two age extremes of pediatric and geriatric MS populations. This review covers epidemiology, diagnosis, and treatment strategies for these populations with nuanced discussions on therapeutic approaches to effectively care for patients living with MS at critical transition points during their lifespan.

Recent Advances in Diagnostic, Prognostic, and Disease-Monitoring Biomarkers in Multiple Sclerosis

Multiple sclerosis (MS) is a highly heterogeneous disease. Currently, a combination of clinical features, MRI, and cerebrospinal fluid markers are used in clinical practice for diagnosis and treatment decisions. In recent years, there has been considerable effort to develop novel biomarkers that better reflect the pathologic substrates of the disease to aid in diagnosis and early prognosis, evaluation of ongoing inflammatory activity, detection and monitoring of disease progression, prediction of treatment response, and monitoring of disease-modifying treatment safety. In this review, the authors provide an overview of promising recent developments in diagnostic, prognostic, and disease-monitoring/treatment-response biomarkers in MS.

Intruders or protectors - the multifaceted role of B cells in CNS disorders

B lymphocytes are immune cells studied predominantly in the context of peripheral humoral immune responses against pathogens. Evidence has been accumulating in recent years on the diversity of immunomodulatory functions that B cells undertake, with particular relevance for pathologies of the central nervous system (CNS). This review summarizes current knowledge on B cell populations, localization, infiltration mechanisms, and function in the CNS and associated tissues. Acute and chronic neurodegenerative pathologies are examined in order to explore the complex, and sometimes conflicting, effects that B cells can have in each context, with implications for disease progression and treatment outcomes. Additional factors such as aging modulate the proportions and function of B cell subpopulations over time and are also discussed in the context of neuroinflammatory response and disease susceptibility. A better understanding of the multifactorial role of B cell populations in the CNS may ultimately lead to innovative therapeutic strategies for a variety of neurological conditions.

Paramagnetic rim lesions and the central vein sign: Characterizing multiple sclerosis imaging markers

BACKGROUND AND PURPOSE

Paramagnetic rims and the central vein sign (CVS) are proposed imaging markers of multiple sclerosis (MS) lesions. Using 7 tesla magnetic resonance imaging, we aimed to: (1) characterize the appearance of paramagnetic rim lesions (PRLs); (2) assess whether PRLs and the CVS are associated with higher levels of MS pathology; and (3) compare the characteristics between subjects with and without PRLs in early MS.

METHODS

Prospective study of 32 treatment-naïve subjects around the time of diagnosis who were assessed for the presence of PRLs and the CVS. Comparisons of lesion volume and macromolecular pool size ratio (PSR) index, a proxy of myelin integrity, between PRLs and non-PRLs, and CVS-positive and CVS-negative lesions were carried out. Differences in clinical/demographic characteristics between patients with PRLs and those without were tested.

RESULTS

Fifteen subjects had ≥1 PRL for a total of 36 PRLs, of which two-thirds had a full rim. PRLs predicted a larger lesion size and decreased PSR signal. Lesion volume and presence of cervical spine lesions were significantly different between subjects with PRLs and those without, although neither remained significant after adjusting for multiple comparisons. One hundred and eighty-one lesions with CVS were identified with no differences between CVS-positive and CVS-negative lesions in volume (p = .27) and PSR values (p = .62).

CONCLUSIONS

PRLs, but not CVS-positive lesions, are larger and have lower myelin integrity. Our findings indicate that PRLs are associated with higher levels of lesion-specific pathology prior to the start of disease-modifying therapy.

Effects of High Efficacy Multiple Sclerosis Disease Modifying Drugs on the Immune Synapse: A Systematic Review

BACKGROUND

Co-signaling and adhesion molecules are important elements for creating immune synapses between T lymphocytes and antigen-presenting cells; they positively or negatively regulate the interaction between a T cell receptor with its cognate antigen, presented by the major histocompatibility complex.

OBJECTIVES

We conducted a systematic review on the effects of High Efficacy Disease Modifying Drugs (HEDMDs) for Multiple Sclerosis (MS) on the co-signaling and adhesion molecules that form the immune synapse.

METHODS

We searched EMBASE, MEDLINE, and other sources to identify clinical or preclinical reports on the effects of HEDMDs on co-signaling and adhesion molecules that participate in the formation of immune synapses in patients with MS or other autoimmune disorders. We included reports on cladribine tablets, anti- CD20 monoclonal antibodies, S1P modulators, inhibitors of Bruton's Tyrosine Kinase, and natalizumab.

RESULTS

In 56 eligible reports among 7340 total publications, limited relevant evidence was uncovered. Not all co-signaling and adhesion molecules have been studied in relation to every HEDMD, with more data being available on the anti-CD20 monoclonal antibodies (that affect CD80, CD86, GITR and TIGIT), cladribine tablets (affecting CD28, CD40, ICAM-1, LFA-1) and the S1P modulators (affecting CD86, ICAM-1 and LFA-1) and less on Natalizumab (affecting CD80, CD86, CD40, LFA-1, VLA-4) and Alemtuzumab (affecting GITR and CTLA-4).

CONCLUSION

The puzzle of HEDMD effects on the immune synapse is far from complete. The available evidence suggests that distinguishing differences exist between drugs and are worth pursuing further.

Neuroimaging to monitor worsening of multiple sclerosis: advances supported by the grant for multiple sclerosis innovation

Key unmet needs in multiple sclerosis (MS) include detection of early pathology, disability worsening independent of relapses, and accurate monitoring of treatment response. Collaborative approaches to address these unmet needs have been driven in part by industry-academic networks and initiatives such as the Grant for Multiple Sclerosis Innovation (GMSI) and Multiple Sclerosis Leadership and Innovation Network (MS-LINK™) programs. We review the application of recent advances, supported by the GMSI and MS-LINK™ programs, in neuroimaging technology to quantify pathology related to central pathology and disease worsening, and potential for their translation into clinical practice/trials. GMSI-supported advances in neuroimaging methods and biomarkers include developments in magnetic resonance imaging, positron emission tomography, ocular imaging, and machine learning. However, longitudinal studies are required to facilitate translation of these measures to the clinic and to justify their inclusion as endpoints in clinical trials of new therapeutics for MS. Novel neuroimaging measures and other biomarkers, combined with artificial intelligence, may enable accurate prediction and monitoring of MS worsening in the clinic, and may also be used as endpoints in clinical trials of new therapies for MS targeting relapse-independent disease pathology.

Expression of Bruton´s tyrosine kinase in different type of brain lesions of multiple sclerosis patients and during experimental demyelination

Background

Inhibition of Bruton's tyrosine kinase (BTK) is an emerging multiple sclerosis (MS) therapy. BTK inhibitors (BTKi) cross the blood-brain barrier and modulate B cells and microglia, major cellular players in active and chronic active lesions.

Objective

To assess potential lesional and cellular targets of BTKi, we examined BTK expression in different type of MS white matter (WM) lesions, in unmanipulated CNS resident cells, and in a degenerative MS model associated with microglia activation in vivo.

Methods

We examined BTK expression by next-generation RNA-sequencing in postmortem 25 control WM, 19 NAWM, 6 remyelinating, 18 active, 13 inactive and 17 chronic active lesions. Presence of B cells and microglia were examined by immunohistochemistry. CNS resident cells were isolated from the mouse brain by magnetic sorting. BTK expression was examined by quantitative PCR in isolated cells and dissected corpus callosum from mice treated with cuprizone (CPZ).

Results

BTK expression was significantly increased in active and chronic active lesions with upregulated complement receptors and Fcγ receptors. Active lesions contained high number of perivascular B cells, microglia, and macrophages. Chronic active lesions were characterized by microglia/macrophages in the rim. Microglia expressed BTK at high level (120-fold) in contrast to other CNS cell types (2-4-fold). BTK expression was increasing during CPZ treatment reaching significance after stopping CPZ.

Conclusion

Considering BTK expression in MS lesions and resident cells, BTKi may exert effect on B cells, microglia/macrophages in active lesions, and limit microglia activation in chronic active lesions, where tissue damage propagates.

Abnormal phosphorylation of protein tyrosine in neurodegenerative diseases

Neurodegenerative diseases, including Alzheimer disease, Parkinson disease, amyotrophic lateral sclerosis, and multiple sclerosis, are chronic disorders of the CNS that are characterized by progressive neuronal dysfunction. These diseases have diverse clinical and pathological features and their pathogenetic mechanisms are not yet fully understood. Currently, widely accepted hypotheses include the accumulation of misfolded proteins, oxidative stress from reactive oxygen species, mitochondrial dysfunction, DNA damage, neurotrophin dysfunction, and neuroinflammatory processes. In the CNS of patients with neurodegenerative diseases, a variety of abnormally phosphorylated proteins play important roles in pathological processes such as neuroinflammation and intracellular accumulation of β-amyloid plaques and tau. In recent years, the roles of abnormal tyrosine phosphorylation of intracellular signaling molecules regulated by protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs) in neurodegenerative diseases have attracted increasing attention. Here, we summarize the roles of signaling pathways related to protein tyrosine phosphorylation in the pathogenesis of neurodegenerative diseases and the progress of therapeutic studies targeting PTKs and PTPs that provide theoretical support for future studies on therapeutic strategies for these devastating and important neurodegenerative diseases.

Remibrutinib (LOU064) inhibits neuroinflammation driven by B cells and myeloid cells in preclinical models of multiple sclerosis

BACKGROUND

Bruton's tyrosine kinase (BTK) is a key signaling node in B cell receptor (BCR) and Fc receptor (FcR) signaling. BTK inhibitors (BTKi) are an emerging oral treatment option for patients suffering from multiple sclerosis (MS). Remibrutinib (LOU064) is a potent, highly selective covalent BTKi with a promising preclinical and clinical profile for MS and other autoimmune or autoallergic indications.

METHODS

The efficacy and mechanism of action of remibrutinib was assessed in two different experimental autoimmune encephalomyelitis (EAE) mouse models for MS. The impact of remibrutinib on B cell-driven EAE pathology was determined after immunization with human myelin oligodendrocyte glycoprotein (HuMOG). The efficacy on myeloid cell and microglia driven neuroinflammation was determined in the RatMOG EAE. In addition, we assessed the relationship of efficacy to BTK occupancy in tissue, ex vivo T cell response, as well as single cell RNA-sequencing (scRNA-seq) in brain and spinal cord tissue.

RESULTS

Remibrutinib inhibited B cell-dependent HuMOG EAE in dose-dependent manner and strongly reduced neurological symptoms. At the efficacious oral dose of 30 mg/kg, remibrutinib showed strong BTK occupancy in the peripheral immune organs and in the brain of EAE mice. Ex vivo MOG-specific T cell recall response was reduced, but not polyclonal T cell response, indicating absence of non-specific T cell inhibition. Remibrutinib also inhibited RatMOG EAE, suggesting that myeloid cell and microglia inhibition contribute to its efficacy in EAE. Remibrutinib did not reduce B cells, total Ig levels nor MOG-specific antibody response. In brain and spinal cord tissue a clear anti-inflammatory effect in microglia was detected by scRNA-seq. Finally, remibrutinib showed potent inhibition of in vitro immune complex-driven inflammatory response in human microglia.

CONCLUSION

Remibrutinib inhibited EAE models by a two-pronged mechanism based on inhibition of pathogenic B cell autoreactivity, as well as direct anti-inflammatory effects in microglia. Remibrutinib showed efficacy in both models in absence of direct B cell depletion, broad T cell inhibition or reduction of total Ig levels. These findings support the view that remibrutinib may represent a novel treatment option for patients with MS.

An update on combination therapies for multiple sclerosis: where are we now?

INTRODUCTION

In theory, combination of two agents, which are suboptimal when given individually, may result in a significant increase in therapeutic effect. Combination therapies have proven particularly effective against infections such as HIV, cancer, and also chronic autoimmune diseases such as rheumatoid arthritis.

AREAS COVERED

The authors review the literature, searching for randomized placebo-controlled or comparative, double-blind or investigator-blinded clinical trials, not including open label clinical trials, of treatment of multiple sclerosis (MS) with combination therapy or add-on therapy, including trials of induction therapy, trials for prevention of disease activity or worsening, amelioration of adverse effects, and treatment of relapses, and trials to increase remyelination.

EXPERT OPINION

Combination of two platform therapies (Interferon-beta or glatiramer acetate) was without additional effect. Clinical trials with add-on, often applying repurposed drugs (e.g. simvastatin, atorvastatin, minocycline, estriol, cyclophosphamide, azathioprine, albuterol, vitamin D), have been negative, apart from monthly methylprednisolone that, however, had low tolerability. Combination therapy for neuroprotection/remyelination showed some interesting results, though we are still awaiting results of phase III trials. The results of combination of anti-inflammatory therapies have in general been disappointing. In the future, combination of new effective neuroprotective/remyelinating drugs and highly effective anti-inflammatory treatments may benefit people with MS.

Central nervous system demyelinating diseases: glial cells at the hub of pathology

Inflammatory demyelinating diseases (IDDs) are among the main causes of inflammatory and neurodegenerative injury of the central nervous system (CNS) in young adult patients. Of these, multiple sclerosis (MS) is the most frequent and studied, as it affects about a million people in the USA alone. The understanding of the mechanisms underlying their pathology has been advancing, although there are still no highly effective disease-modifying treatments for the progressive symptoms and disability in the late stages of disease. Among these mechanisms, the action of glial cells upon lesion and regeneration has become a prominent research topic, helped not only by the discovery of glia as targets of autoantibodies, but also by their role on CNS homeostasis and neuroinflammation. In the present article, we discuss the participation of glial cells in IDDs, as well as their association with demyelination and synaptic dysfunction throughout the course of the disease and in experimental models, with a focus on MS phenotypes. Further, we discuss the involvement of microglia and astrocytes in lesion formation and organization, remyelination, synaptic induction and pruning through different signaling pathways. We argue that evidence of the several glia-mediated mechanisms in the course of CNS demyelinating diseases supports glial cells as viable targets for therapy development.

Role of Microglial Cells in the Pathophysiology of MS: Synergistic or Antagonistic?

Many studies indicate an important role of microglia and their cytokines in the pathophysiology of multiple sclerosis (MS). Microglia are the macrophages of the central nervous system (CNS). They have many functions, such as being "controllers" of the CNS homeostasis in pathological and healthy conditions, playing a key role in the active immune defense of the CNS. Macroglia exhibit a dual role, depending on the phenotype they adopt. First, they can exhibit neurotoxic effects, which are harmful in the case of MS. However, they also show neuroprotective and regenerative effects in this disease. Many of the effects of microglia are mediated through the cytokines they secrete, which have either positive or negative properties. Neurotoxic and pro-inflammatory effects can be mediated by microglia via lipopolysaccharide and gamma interferon. On the other hand, the mediators of anti-inflammatory and protective effects secreted by microglia can be, for example, interleukin-4 and -13. Further investigation into the role of microglia in MS pathophysiology may perhaps lead to the discovery of new therapies for MS, as recent research in this area has been very promising.

The therapeutic value of treatment for multiple sclerosis: analysis of health technology assessments of three European countries

In accordance with European regulation, medicines containing a new active substance to treat neurodegenerative diseases as well as autoimmune and other immune dysfunctions must be approved by the European Medicines Agency (EMA) through the centralized procedure before they can be marketed. However, after EMA approval, each country is responsible for national market access, following the assessment performed by health technology assessment (HTA) bodies with regard to the therapeutic value. This study aims to provide a comparative analysis of HTA recommendations issued by three EU countries (France, Germany, and Italy) for new drugs for multiple sclerosis (MS) following EMA approval. In the reference period, we identified 11 medicines authorized in Europe for MS, including relapsing forms of MS (RMS; n = 4), relapsing-remitting MS (RRMS; n = 6), secondary progressive MS (SPMS; n = 1), and the primary progressive form (PPMS; n = 1). We found no agreement on the therapeutic value (in particular, the "added value" compared to the standard of care) of the selected drugs. Most evaluations resulted in the lowest score ("additional benefit not proven/no clinical improvement"), underlining the need for new molecules with better efficacy and safety profiles for MS, especially for some forms and clinical settings.