Disease activity in primary progressive multiple sclerosis:a systematic review and meta-analysis

Background: Disease activity in multiple sclerosis (MS) is defined as presence of relapses, gadolinium enhancing lesions and/or new or enlarging lesions on MRI. It is associated with efficacy of immunomodulating therapies (IMTs) in primary progressive MS (PPMS). However, a thorough review on disease activity in PPMS is lacking. In relapsing remitting MS, the prevalence of activity decreases in more contemporary cohorts. For PPMS, this is unknown. Aim: To review disease activity in PPMS cohorts and identify its predictors. Methods: A systematic search in EMBASE, MEDLINE, Web of science Core Collection, COCHRANE CENTRAL register of trials, and GOOGLE SCHOLAR was performed. Keywords included PPMS, inflammation, and synonyms. We included original studies with predefined available data, extracted cohort characteristics and disease activity outcomes and performed meta-regression analyses. Results: We included 34 articles describing 7,109 people with PPMS (pwPPMS). The weighted estimated proportion of pwPPMS with overall disease activity was 26.8% (95% CI 20.6–34.0%). A lower age at inclusion predicted higher disease activity (OR 0.91, p = 0.031). Radiological activity (31.9%) was more frequent than relapses (9.2%), and was predicted by longer follow-up duration (OR 1.27, p = 0.033). Year of publication was not correlated with disease activity. Conclusion: Inflammatory disease activity is common in PPMS and has remained stable over the last decades. Age and follow-up duration predict disease activity, advocating prolonged monitoring of young pwPPMS to evaluate potential IMT benefits

Benefits of early highly effective versus escalation treatment strategies in relapsing multiple sclerosis estimated using a treatment-sequence model

BACKGROUND: Uncertainty about disproportionate impact on health care budgets limits implementation of early highly effective treatment (EHT) in multiple sclerosis (MS).OBJECTIVE: To estimate cost-effectiveness of escalation versus EHT disease-modifying treatment (DMT) sequences.METHODS: Using a health-economic approach, we analysed health benefits (relapse rate reduction, disability prevention), direct/indirect DMT and societal costs of escalation versus EHT DMT sequences. In scenario analyses, we allowed (1) earlier use of alemtuzumab (ALE) and (2) a single retreatment with cladribine (CLA).RESULTS: In our model, we showed that the ratio between costs and quality-adjusted life years (QALYs) for the most cost-effective EHT and escalation sequence results into a similar net health benefit with higher costs and also higher QALYs associated with an EHT versus escalation strategy. Earlier use of ALE is more cost-effective than in later lines, even when aggravating the impact of its side-effects tenfold. Retreatment with CLA was more cost-effective in both escalation and EHT sequences.CONCLUSIONS: Certain EHT sequences are equally cost-effective to escalation sequences and are likely to result in more health at uncertain additional costs. The favourable cost-benefit ratio of CLA and ALE suggests that a wider application of affordable highly effective therapies could promote the cost-effectiveness both EHT and escalation approaches.</p

Health-economic benefits of anti-CD20 treatments in relapsing multiple sclerosis estimated using a treatment-sequence model

Background: In high-income countries, four anti-CD20 monoclonal antibodies (mAbs) are used or in thepipeline for relapsing MS: ocrelizumab, ofatumumab (both registered), ublituximab (awaiting registration)and rituximab (off-label). List prices differ significantly between registered and off-label drugs.Objective: Comparing differences in benefits between anti-CD20 mAbs from a health-economic and societal perspective.Methods: To reflect lifetime use of DMTs, we used a treatment-sequence model to compare ocrelizumab/ofatumumab and eight other drug classes in terms of health (lifetime relapses, time to Expanded DisabilityStatus Scale [EDSS] 6, lifetime quality-adjusted life years) and cost-effectiveness (net health benefit). Tobecome cost-effective compared to ocrelizumab, we modelled the list price of ublituximab and desiredeffect on EDSS progression of rituximab.Results: Although drug sequences with ocrelizumab in first- and second-line were more cost-effective thanofatumumab, our probabilistic analysis suggests this outcome was very uncertain. To be more cost-effective than ocrelizumab, ublituximab needs to be about 25% cheaper whilst rituximab needs to equal theeffect on disability progression seen with first-line treatments.Conclusions: Our model showed no clear difference in cost-effectiveness between ocrelizumab and ofatumumab. Hence, prescribing the least costly anti-CD20 mAb can democratise MS care without a loss inhealth benefits

Benefits of sphingosine-1-phosphate receptor modulators in relapsing MS estimated with a treatment sequence model

BackgroundThree sphingosine-1-phosphate receptor (S1PR) modulators are currently available as disease-modifying therapies (DMTs) for relapsing MS in the Netherlands (i.e. fingolimod, ozanimod and ponesimod). We aimed to identify which S1PR modulator yields the highest benefit from a health-economic and societal perspective during a patient's lifespan.MethodsIncorporating Dutch DMT list prices, we used the ErasmusMC/iMTA MS model to compare DMT sequences, including S1PR modulators and eight other DMT classes, for treatment-naïve patients with relapsing MS in terms of health outcomes (number of lifetime relapses, time to Expanded Disability Status Scale (EDSS) 6, lifetime quality-adjusted life years (QALYs)) and cost-effectiveness (net health benefit (NHB)). We estimated the influence of list price and EDSS progression on cost-effectiveness outcomes.ResultsIn deterministic and probabilistic analysis, DMT sequences with ponesimod have lower lifetime costs and higher QALYs resulting in a higher average NHB compared to sequences with other S1PR modulators. Ponesimod remains the most cost-effective S1PR modulator when EDSS progression is class-averaged. Given the variable effects on disability progression, list price reductions could make fingolimod but not ozanimod more cost-effective than ponesimod.ConclusionOur model favours ponesimod among the S1PR modulators for the treatment of relapsing MS. This implies that prioritizing ponesimod over other S1PR modulators translates into a more efficacious spending of national healthcare budget without reducing benefit for people with MS. Prioritizing cost-effective choices when counselling patients contributes to affordable and accessible MS care

Epstein-Barr virus and genetic risk variants as determinants of T-bet⁺ B cell-driven autoimmune diseases

B cells expressing the transcription factor T-bet are found to have a protective role in viral infections, but are also considered major players in the onset of different types of autoimmune diseases. Currently, the exact mechanisms driving such 'atypical' memory B cells to contribute to protective immunity or autoimmunity are unclear. In addition to general autoimmune-related factors including sex and age, the ways T-bet+ B cells instigate autoimmune diseases may be determined by the close interplay between genetic risk variants and Epstein-Barr virus (EBV). The impact of EBV on T-bet+ B cells likely relies on the type of risk variants associated with each autoimmune disease, which may affect their differentiation, migratory routes and effector function. In this hypothesis-driven review, we discuss the lines of evidence pointing to such genetic and/or EBV-mediated influence on T-bet+ B cells in a range of autoimmune diseases, including systemic lupus erythematosus (SLE) and multiple sclerosis (MS). We provide examples of how genetic risk variants can be linked to certain signaling pathways and are differentially affected by EBV to shape T-bet+ B-cells. Finally, we propose options to improve current treatment of B cell-related autoimmune diseases by more selective targeting of pathways that are critical for pathogenic T-bet+ B-cell formation.</p

B and T Cells Driving Multiple Sclerosis: Identity, Mechanisms and Potential Triggers

Historically, multiple sclerosis (MS) has been viewed as being primarily driven by T cells. However, the effective use of anti-CD20 treatment now also reveals an important role for B cells in MS patients. The results from this treatment put forward T-cell activation rather than antibody production by B cells as a driving force behind MS. The main question of how their interaction provokes both B and T cells to infiltrate the CNS and cause local pathology remains to be answered. In this review, we highlight key pathogenic events involving B and T cells that most likely contribute to the pathogenesis of MS. These include (1) peripheral escape of B cells from T cell-mediated control, (2) interaction of pathogenic B and T cells in secondary lymph nodes, and (3) reactivation of B and T cells accumulating in the CNS. We will focus on the functional programs of CNS-infiltrating lymphocyte subsets in MS patients and discuss how these are defined by mechanisms such as antigen presentation, co-stimulation and cytokine production in the periphery. Furthermore, the potential impact of genetic variants and viral triggers on candidate subsets will be debated in the context of MS

Ocrelizumab associates with reduced cerebrospinal fluid B and CD20^dim CD4⁺ T cells in primary progressive multiple sclerosis

The anti-CD20 monoclonal antibody ocrelizumab reduces disability progression in primary progressive multiple sclerosis. CD20 is a prototypical B-cell marker; however, subpopulations of CD4 + and CD8 + T cells in peripheral blood and cerebrospinal fluid also express low levels of CD20 (CD20 dim). Therefore, direct targeting and depletion of these CD20 dim T-cell subpopulations may contribute to the therapeutic effect of ocrelizumab. The aim of this observational cohort study was to compare CD20 + B-cell and CD20 dim T-cell distributions between peripheral blood and cerebrospinal fluid of ocrelizumab-treated or ocrelizumab-untreated people with primary progressive multiple sclerosis. Ocrelizumab treatment was associated with depletion of circulating B cells and CD20 dim CD4 + and CD20 dim CD8 + T cells (P &lt; 0.0001, P = 0.0016 and P = 0.0008, respectively) but, in cerebrospinal fluid, only with lower proportions of B cells and CD20 dim memory CD4 + T cells (P &lt; 0.0001 and P = 0.0043, respectively). The proportional prevalence of cerebrospinal fluid CD20 dim memory CD8 + T cells was not significantly reduced (P = 0.1333). Only in cerebrospinal fluid, the proportions of CD20 dim cells within CD4 + and not CD8 + T cells positive for CCR5, CCR6 and CXCR3 were reduced in ocrelizumab-treated participants. The proportion of CD20 dim CD4 + T cells and abundance of CD4 + relative to CD8 + T cells in cerebrospinal fluid correlated positively with age (R = 0.6799, P = 0.0150) and Age-Related Multiple Sclerosis Severity score (R = 0.8087, P = 0.0014), respectively. We conclude that, in contrast to cerebrospinal fluid CD20 dim CD8 + T cells, B cells and CD20 dim CD4 + T cells are reduced in cerebrospinal fluid of people with primary progressive multiple sclerosis with an ocrelizumab-associated depletion of circulating B cells and CD20 dim T cells. Therefore, these cells are likely to contribute to the therapeutic effects of ocrelizumab in people with primary progressive multiple sclerosis.</p

Twin study dissects CXCR3

Background: In multiple sclerosis (MS), B cells are considered main triggers of the disease, likely as the result of complex interaction between genetic and environmental risk factors. Studies on monozygotic twins discordant for MS offer a unique way to reduce this complexity and reveal discrepant subsets. Methods: In this study, we analyzed B cell subsets in blood samples of monozygotic twins with and without MS using publicly available data. We verified functional characteristics by exploring the role of therapy and performed separate analyses in unrelated individuals. Findings: The frequencies of CXCR3 + memory B cells were reduced in the blood of genetically identical twins with MS compared to their unaffected twin siblings. Natalizumab (anti-VLA-4 antibody) was the only treatment regimen under which these frequencies were reversed. The CNS-homing features of CXCR3 + memory B cells were supported by elevated CXCL10 levels in MS cerebrospinal fluid and their in vitro propensity to develop into antibody -secreting cells. Conclusions: Circulating CXCR3 + memory B cells are affected by nonheritable cues in people who develop MS. This underlines the requirement of environmental risk factors such as Epstein -Barr virus in triggering these B cells. We propose that after CXCL10-mediated entry into the CNS, CXCR3 + memory B cells mature into antibody -secreting cells to drive MS