Long-term Clinical Outcomes of Hematopoietic Stem Cell Transplantation in Multiple Sclerosis

Evolving understanding of autoimmune mechanisms and new therapeutic strategies of autoimmune disorders

Autoimmune disorders are characterized by aberrant T cell and B cell reactivity to the body's own components, resulting in tissue destruction and organ dysfunction. Autoimmune diseases affect a wide range of people in many parts of the world and have become one of the major concerns in public health. In recent years, there have been substantial progress in our understanding of the epidemiology, risk factors, pathogenesis and mechanisms of autoimmune diseases. Current approved therapeutic interventions for autoimmune diseases are mainly non-specific immunomodulators and may cause broad immunosuppression that leads to serious adverse effects. To overcome the limitations of immunosuppressive drugs in treating autoimmune diseases, precise and target-specific strategies are urgently needed. To date, significant advances have been made in our understanding of the mechanisms of immune tolerance, offering a new avenue for developing antigen-specific immunotherapies for autoimmune diseases. These antigen-specific approaches have shown great potential in various preclinical animal models and recently been evaluated in clinical trials. This review describes the common epidemiology, clinical manifestation and mechanisms of autoimmune diseases, with a focus on typical autoimmune diseases including multiple sclerosis, type 1 diabetes, rheumatoid arthritis, systemic lupus erythematosus, and sjögren's syndrome. We discuss the current therapeutics developed in this field, highlight the recent advances in the use of nanomaterials and mRNA vaccine techniques to induce antigen-specific immune tolerance.

Exploring the therapeutic potential of autologous hematopoietic stem cell transplantation in progressive multiple sclerosis-a systematic review

BACKGROUND AND PURPOSE

The aim was to determine the value of autologous haematopoietic stem cell transplantation (aHSCT) as a therapeutic intervention for progressive multiple sclerosis (PMS) based on a systematic review of the current literature.

METHODS

All studies from the databases PubMed and Google Scholar published in English before February 2024 which provided individual data for PMS patients were systematically reviewed. PICO was defined as population (P), primary progressive MS and secondary progressive MS patients; intervention (I), treatment with aHSCT; comparison (C), none, disease-modifying therapy treated/relapsing-remitting MS cohorts if available; outcome (O), transplant-related mortality, progression-free survival (PFS) and no evidence of disease activity.

RESULTS

A total of 15 studies met the criteria including 665 patients with PMS (74 primary progressive MS, 591 secondary progressive MS) and 801 patients with relapsing-remitting MS as controls. PFS data were available for 647 patients. PMS patients showed more severe disability at baseline than relapsing-remitting MS patients. The average transplant-related mortality for PMS in 10 studies was 1.9%, with 10 deaths in 528 patients. PFS ranged from 0% to 78% in PMS groups 5 years after treatment initiation, demonstrating a high variability. No evidence of disease activity scores at 5 years ranged from 0% to 75%.

CONCLUSION

Based on the available data, aHSCT does not halt progression in people with PMS. However, there appears to be evidence of improved outcome in selected patients. Due to the heterogeneity of the available data, more comprehensive clinical trials assessing the efficacy of aHSCT across different patient groups are urgently needed to reduce variability and improve patient stratification.

Spinal cord size as promising biomarker of disability outcomes after hematopoietic stem cell transplantation in multiple sclerosis

BACKGROUND

Biomarkers predictive of disability outcomes in individual multiple sclerosis (MS) patients undergoing autologous haematopoietic stem cell transplantation (AHSCT) are currently lacking. As correlations between spinal cord atrophy and clinical disability in MS were previously described, in this study spinal cord size was investigated in MS patients treated with AHSCT, exploring whether baseline spinal cord volume may predict disability progression after AHSCT.

METHODS

relapsing-remitting (RR-) and secondary-progressive (SP-) MS patients treated with AHSCT (BEAM/ATG regimen) at a single academic centre in Florence, who performed at least two standardized brain magnetic resonance imaging (MRIs) scans (acquired between one-year pre-AHSCT to 5 years after AHSCT) were included. Cervical spinal cord atrophy was estimated as upper cervical spinal cord cross-sectional area (SCCSA). Brain volume loss (BVL) was analysed at the same timepoints.

RESULTS

Eleven (8 RR-; 3 SP-) MS patients were included. Over a median follow-up of 66 (range 37 - 100) months, no relapses nor brain MRI activity were observed; disability progressed in 2 cases (both SP-MS). Baseline SCCSA was associated with EDSS change between pre- and one-year post-AHSCT. Compared to patients who stabilized, patients who progressed after AHSCT tended to have lower SCCSA at C4 level at baseline and year 1 after AHSCT. Longitudinal changes in SCCSA or BVL did not correlate with EDSS change.

CONCLUSIONS

Baseline pre-AHSCT SCCSA, but not its longitudinal changes nor BVL, predicted EDSS change within the two years following AHSCT. SCCSA may represent a biomarker of treatment response and a promising screening tool for assessing patient eligibility for high-impact treatments such as AHSCT.

Ocrelizumab in MS patients with persistence of disease activity after alemtuzumab: A multi-center Italian study

BACKGROUND

The reason why some multiple sclerosis (MS) patients show disease activity after alemtuzumab (ALM) is still unclear, but ocrelizumab (OCR) could represent an interesting sequential therapeutic approach.

OBJECTIVES

To investigate safety and efficacy of OCR in MS patients with disease activity after two ALM courses.

METHODS

Observational retrospective multi-centers Italian cohort study.

RESULTS

Seventy-two subjects were included. Mean follow-up (FU) was 2.4 (±1) years. Forty-five patients (62.5%) experienced at least one adverse event (AE), with infections accounting for 96.7% of cases. A reduction in total lymphocytes was observed between OCR start and 6 months FU, driven by BCD19+ lymphocytes depletion (p < 0.001). Immunoglobulin M (IgM) levels decreased between OCR start and 6 months FU (p < 0.001). At 2-year FU, relapse, magnetic resonance imaging (MRI) activity and disability worsening-free survival were 92.1%, 90.8%, and 89.2%. The evidence of inflammatory activity between the two ALM courses was associated with higher risk of relapse, MRI activity, and NEDA-3 status loss in relapsing-remitting multiple sclerosis (RRMS; p = 0.02, p = 0.05, p = 0.01, respectively).

CONCLUSIONS

OCR after two ALM courses seemed to be safe and effective. Early IgM hypogammaglobulinemia occurred in a high proportion of patients. The evidence of inflammatory activity between ALM courses seemed to increase the risk of MS re-activation on OCR treatment.

Neuropsychological outcomes following HSCT in MS: A systematic review

BACKGROUND

Autologous haematopoietic stem cell transplant (HSCT) is considered an effective treatment for highly active multiple sclerosis (MS). To date, most research has focused primarily on disease outcome measures, despite the significant impact of neuropsychological symptoms on MS patients' quality of life. The current systematic review aimed to examine whether HSCT for MS impacts neuropsychological outcome measures such as cognition, fatigue, mood, and quality of life.

METHODS

The review was registered with the International Prospective Register of Systematic Reviews (PROSPERO, ID: CRD42023474214). Systematic searches were carried out in six databases (PsycINFO, PubMed, Embase, Scopus, CINAHL and Web of Science) based on the following inclusion criteria: (i) published in peer-reviewed journals in English; (ii) longitudinal studies of adults with MS (iii) at least one neuropsychological outcome was assessed pre- and post-HSCT using standardised measures. Risk of bias was assessed using the National Heart, Lung and Blood Institute (NHLBI) quality assessment tools. A narrative synthesis was used to present results.

RESULTS

Eleven studies were included in the review. Long-term improvements in quality of life post-HSCT were identified. In terms of cognition and fatigue, the evidence was mixed, with some post-HSCT improvements identified. Decline in cognitive performance in the short-term post-HSCT was observed. No changes in mood were identified post-HSCT. Arguments for interpreting these results with caution are presented based on risk of bias. Arguments for interpreting these results with caution are presented based on risk of bias. Limitations of the evidence are discussed, such confounding variables and lack of statistical power.

CONCLUSION

The evidence base for the impact of HSCT for MS on neuropsychological outcomes is limited. Further research is required to progress understanding to facilitate clinician and patient understanding of HSCT treatment for MS.

Effectiveness of autologous haematopoietic stem cell transplantation versus natalizumab in progressive multiple sclerosis

BACKGROUND

Natalizumab was not shown to modify disability in progressive multiple sclerosis (MS). This matched observational study compared the effectiveness of autologous haematopoietic stem cell transplantation (AHSCT) with natalizumab in progressive MS.

METHODS

Patients with primary/secondary progressive MS from seven AHSCT MS centres and the MSBase registry, treated with AHSCT or natalizumab, were matched on a propensity score derived from sex, age, Expanded Disability Status Scale (EDSS), number of relapses 12/24 months before baseline, time from MS onset, the most effective prior therapy and country. The pairwise-censored groups were compared on hazards of 6-month confirmed EDSS worsening and improvement, relapses and annualised relapse rates (ARRs), using Andersen-Gill proportional hazards models and conditional negative binomial model.

RESULTS

39 patients treated with AHSCT (37 with secondary progressive MS, mean age 37 years, EDSS 5.7, 28% with recent disability progression, ARR 0.54 during the preceding year) were matched with 65 patients treated with natalizumab. The study found no evidence for difference in hazards of confirmed EDSS worsening (HR 1.49, 95% CI 0.70 to 3.14) and improvement (HR 1.50, 95% CI 0.22 to 10.29) between AHSCT and natalizumab over up to 4 years. The relapse activity was also similar while treated with AHSCT and natalizumab (ARR: mean±SD 0.08±0.28 vs 0.08±0.25; HR 1.05, 95% CI 0.39 to 2.82). In the AHSCT group, 3 patients experienced febrile neutropenia during mobilisation, 9 patients experienced serum sickness, 6 patients required intensive care unit admission and 36 patients experienced complications after discharge. No treatment-related deaths were reported.

CONCLUSION

This study does not support the use of AHSCT to control disability in progressive MS with advanced disability and low relapse activity.

Cost and effectiveness of autologous haematopoietic stem cell transplantation and high-efficacy disease-modifying therapies in relapsing-remitting multiple sclerosis

BACKGROUND

Autologous haematopoietic stem cell transplantation (AHSCT) is a highly effective one-off treatment for relapsing-remitting multiple sclerosis (RR-MS), potentially representing an optimal front-loading strategy for costs.

OBJECTIVE

Exploring cost/effectiveness of AHSCT and high-efficacy disease-modifying treatments (HE-DMTs) in RR-MS, estimating costs at our centre in Italy, where National Health Service (NHS) provides universal health coverage.

METHODS

Costs (including drugs, inpatient/outpatient management) for treatment with AHSCT and HE-DMTs were calculated as NHS expenditures over 2- and 5-year periods. Cost-effectiveness for each treatment was estimated as "cost needed to treat" (CNT), i.e. expense to prevent relapses, progression, or disease activity (NEDA) in one patient over n-years, retrieving outcomes from published studies.

RESULTS

Costs of AHSCT and HE-DMTs were similar over 2 years, whereas AHSCT was cheaper than most HE-DMTs over 5 years (€46 600 vs €93 800, respectively). When estimating cost-effectiveness of treatments, over 2 years, mean CNT of HE-DMTs for NEDA was twofold that of AHSCT, whereas it was similar for relapses and disability. Differences in CNT were remarkable over 5 years, especially for NEDA, being mean CNT of HE-DMTs €382 800 vs €74 900 for AHSCT.

CONCLUSIONS

AHSCT may be highly cost-effective in selected aggressive RR-MS. Besides priceless benefits for treated individuals, cost-savings generated by AHSCT may contribute to improving healthcare assistance at a population level.

Healthcare utilization and costs associated with autologous haematopoietic stem cell transplantation in Norwegian patients with relapsing remitting multiple sclerosis

Multiple sclerosis (MS) patients experience long-term deterioration of neurological function, reduced quality of life, long-lasting treatment cycles, and an increased risk of early workability loss imposing an economic burden to society. Autologous haematopoietic stem cell transplantation (AHSCT) has shown promising treatment effects for relapsing remitting MS (RRMS). This study employs a micro-costing approach to estimate healthcare utilization and costs associated with AHSCT in Norwegian RRMS patients. Patient-level data were extracted from medical journals of 30 RRMS patients receiving AHSCT treatment at Haukeland University Hospital in the period from January 2015 to January 2018. The time horizon for the analysis was from the pretransplant screening until one year after AHSCT. A correlation was found between patient body weight and total healthcare cost. The average total healthcare cost of AHSCT for RRMS patients was estimated to EUR 66 304 (95% CI: EUR 63 598 - EUR 69 010) including costs associated with the pre-AHSCT period, AHSCT treatment phases and one-year follow-up. The majority of the costs, EUR 64 329, occurred during the treatment phase and within the first 100 days after AHSCT. The results indicate that long-term healthcare cost savings may be achieved using AHSCT in selected patients with aggressive RRMS. This is due to the high costs of most used disease modifying treatments. Further research including long-term clinical data is needed to determine the cost-effectiveness of this treatment.

Benefits of aHSCT over alemtuzumab in patients with multiple sclerosis besides disability and relapses: Sustained improvement in cognition and quality of life

BACKGROUND

Autologous hematopoietic stem cell transplantation (aHSCT) exhibits promising results for multiple sclerosis (MS) in the short term. We investigated the long-term outcome differences in disease progression and cognitive impairment after aHSCT and alemtuzumab treatment.

METHODS

20 patients receiving aHSCT and 21 patients treated with alemtuzumab between 2007 and 2020 were included in this monocentric observational cohort study. The primary objective was to compare the outcome of both groups with regards to achieving No Evidence of Disease Activity (NEDA-3), defined by the absence of relapses, EDSS progression, and MRI activity. Secondary endpoints in the study included the assessment of neurocognitive functioning, quality of life (QoL), Multiple Sclerosis Functional Composite (MSFC), and EDSS improvement.

RESULTS

Baseline characteristics between both groups were comparable, except for a longer disease duration in the alemtuzumab group of 11.3 years compared to 5.4 years in aHSCT-treated patients (p = 0.002) and a longer mean follow-up time in the aHSCT cohort of 9.0 (range 2.8-15.7) years compared to 5.9 years (range 0.9-9.2) in alemtuzumab patients. NEDA-3 was more frequently observed in the aHSCT group with 75.0 % and 55.0 % at five and 10 years, respectively, than in the alemtuzumab group with only 40.0 % at five years (p = 0.012). Relapse free survival was higher in the aHSCT group (p < 0.001). None of the aHSCT-treated patients showed new T2-lesions six months after therapy initiation until the end of the observational period in contrast to 35.0 % of the alemtuzumab-treated patients showing new T2-lesions (95 %CI 14.2-98.9, p = 0.002). aHSCT-treated patients showed significantly improved cognitive performance in five out of 12 cognitive tests whereas alemtuzumab treated patients deteriorated in four out of 12 tests. Quality of life remained on a constant level for up to 10 years in patients receiving aHSCT with improved scores for the subscale fatigue (p = 0.013).

CONCLUSION

aHSCT seems to be superior to alemtuzumab in maintaining long-term NEDA-3 status, improving cognition and stabilizing quality of life for up to 10 years.

Haematopoietic stem cell transplantation for treatment of relapsing-remitting multiple sclerosis in Sweden: an observational cohort study

BACKGROUND

A growing evidence base supports the use of autologous haematopoietic stem cell transplantation (aHSCT) for treatment of relapsing-remitting multiple sclerosis (RRMS), but it has not yet been integrated into most national clinical guidelines. The objective of this study was to assess efficacy and safety when aHSCT is implemented in routine healthcare.

METHODS

We assessed 231 patients and the final analysis included 174 RRMS patients who were treated with aHSCT in Sweden before 1 January 2020. Efficacy was evaluated by performing a retrospective analysis of prospectively collected data from the Swedish MS registry. Procedure-related safety was assessed by analysing data from electronic patient records covering a period of 100 days following aHSCT.

RESULTS

With a median follow-up time of 5.5 (IQR: 3.4-7.5) years, the Kaplan-Meier estimate for no evidence of disease activity was 73% (95% CI 66% to 81%) at 5 years and 65% (95% CI 57% to 75%) at 10 years. Out of the 149 patients with baseline disability, 80 (54%) improved, 55 (37%) were stable and 14 (9%) deteriorated. The mean number of adverse events per patient was 1.7 (±SD: 1.5) for grade 3 events and 0.06 (±SD: 0.3) for grade 4 events. Febrile neutropenia was the most common adverse event, affecting 68% of patients. There was no treatment-related mortality.

CONCLUSIONS

Treatment with aHSCT for RRMS is associated with freedom from disease activity in a majority of patients, with acceptable adverse events. This procedure should be considered a standard of care for patients with highly active RRMS.

Autologous hematopoietic stem cell transplantation is superior to alemtuzumab in patients with highly active relapsing multiple sclerosis and severe disability

OBJECTIVE

To assess the differences of treatment outcomes regarding disease activity in patients with highly active relapsing multiple sclerosis (RMS), treated with autologous hematopoietic stem cell transplantation (HSCT) or alemtuzumab (ATZ).

METHODS

Open-label prospective single-center observational cohort study, enrolling patients with highly active RMS for treatment with ATZ or HSCT between 2014 and 2021.

RESULTS

A total of 50 patients (31/50 (62 %) in HSCT vs 19/50 (38 %) in ATZ group) were included. There were no significant differences in relapse rate, MRI activity or disability worsening between the two study groups during the first two years after treatment onset. However, at 3 to 5 years follow-up, HSCT was superior to ATZ in all the aforementioned aspects. Kaplan-Meier analysis at 5 years post treatment revealed superiority of HSCT in relapse rate (69.6 % vs 95.7 %, p = 0.027), MRI activity (54.5 % vs 75.1 %, p = 0.038) and disability worsening (57.1 % vs 90.9 %, p =  0.031).

CONCLUSIONS

ATZ may halt disability progression early in the course of highly active RMS, but the disability starts accumulating later, while in HSCT patients disability improvement is consistent both 3 and 5 years after treatment onset.

Bioavailable central nervous system disease-modifying therapies for multiple sclerosis

Disease-modifying therapies for relapsing multiple sclerosis reduce relapse rates by suppressing peripheral immune cells but have limited efficacy in progressive forms of the disease where cells in the central nervous system play a critical role. To our knowledge, alemtuzumab, fumarates (dimethyl, diroximel, and monomethyl), glatiramer acetates, interferons, mitoxantrone, natalizumab, ocrelizumab, ofatumumab, and teriflunomide are either limited to the periphery or insufficiently studied to confirm direct central nervous system effects in participants with multiple sclerosis. In contrast, cladribine and sphingosine 1-phosphate receptor modulators (fingolimod, ozanimod, ponesimod, and siponimod) are central nervous system-penetrant and could have beneficial direct central nervous system properties.

Electroacupuncture at ST36 acupoint regulates stem cells during experimental autoimmune encephalomyelitis

BACKGROUND

Electroacupuncture (EA) is given to assist in the treatment of MS, which is an effective therapeutic method. However, the therapy mechanism of EA related to stem cells in the treatment of MS is not yet known. In this study, we used a classic animal model of multiple sclerosis: experimental autoimmune encephalomyelitis (EAE) to evaluate the therapeutic effect of EA at Zusanli (ST36) acupoint in EAE and shed light on its potential roles in the effects of stem cells in vivo.

METHODS

The EAE animal models were established. From the first day after immunization, EAE model mice received EA at ST36 acupoint, named the EA group. The weight and clinical score of the three groups were recorded for 28 days. The demyelination, inflammatory cell infiltration, and markers of neural stem cells (NSCs), hematopoietic stem cells (HSCs), and mesenchymal stem cells (MSCs) were compared.

RESULTS

We showed that EAE mice treated with EA at ST36 acupoint, were suppressed in demyelination and inflammatory cell infiltration, and thus decreased clinical score and weight loss and mitigated the development of EAE when compared with the EAE group. Moreover, our data revealed that the proportions of NSCs, HSCs, and MSCs increased in the EA group compared with the EAE group.

CONCLUSIONS

Our study suggested that EA at ST36 acupoint was an effective nonpharmacological therapeutic protocol that not only reduced the CNS demyelination and inflammatory cell infiltration in EAE disease but also increased the proportions of various stem cells. Further study is necessary to better understand how EA at the ST36 acupoint affects EAE.

Escalation Versus Induction/High-Efficacy Treatment Strategies for Relapsing Multiple Sclerosis: Which is Best for Patients?

After more than 2 decades of recommending an escalating strategy for the treatment of most patients with multiple sclerosis, there has recently been considerable interest in the use of high-efficacy therapies in the early stage of the disease. Early intervention with induction/high-efficacy disease-modifying therapy may have the best risk-benefit profile for patients with relapsing-remitting multiple sclerosis who are young and have active disease, numerous focal T2 lesions on spinal and brain magnetic resonance imaging, and no irreversible disability. Although we have no curative treatment, at least seven classes of high-efficacy drugs are available, with two main strategies. The first strategy involves the use of high-efficacy drugs (e.g., natalizumab, sphingosine 1-phosphate receptor modulators, or anti-CD20 drugs) to achieve sustained immunosuppression. These can be used as a first-line therapy in many countries. The second strategy entails the use of one of the induction drugs (short-term use of mitoxantrone, alemtuzumab, cladribine, or autologous hematopoietic stem cell transplant) that are mainly recommended as a second-line or third-line treatment in patients with very active or aggressive multiple sclerosis disease. Early sustained immunosuppression exposes patients to heightened risks of infection and cancer proportionate to cumulative exposure, and induction drugs expose patients to similar risks during the initial post-treatment period, although these risks decrease over time. Their initial potential safety risks should now be revisited, taking account of long-term data and some major changes in their regimens: natalizumab with the long-term monitoring of John Cunningham virus; use of monthly courses of mitoxantrone with maximum cumulative doses of 36-72 mg/m2, followed by a safer disease-modifying drug; cladribine with only 2-weekly treatment courses required in years 1 and 2 and no systematic treatment for the following 2 years; alemtuzumab, whose safety and clinical impacts have now been documented for more than 6 years after the last infusion; and autologous haematopoietic stem cell transplant, which dramatically reduces transplantation-related mortality with a new regimen and guidelines. Escalation and induction/high-efficacy treatments need rigorous magnetic resonance imaging monitoring. Monitoring over the first few years, using the MAGNIMS score or American Academy of Neurology guidelines, considerably improves prediction accuracy and facilitates the selection of patients with relapsing-remitting multiple sclerosis requiring aggressive treatment.

Stem Cell Transplantation for Multiple Sclerosis: A 2023 Review of Published Studies

This comprehensive literature review underscores the potential of stem cell transplantation (SCT) as a therapeutic intervention for multiple sclerosis (MS). By amalgamating evidence from various sources, including randomized controlled trials (RCTs), observational, retrospective, and comparative studies, this review offers a holistic understanding of SCT's effectiveness, safety, and feasibility in diverse contexts of MS management. SCT has shown promise in mitigating disease activity and progression, particularly in relapsing-remitting MS (RRMS). RCTs like the high dose immunoablation and autologous hematopoietic stem cell transplantation in MS (ASTIMS) versus mitoxantrone therapy in severe multiple sclerosis and multiple sclerosis international stem cell transplant (MIST) trials reveal SCT's capacity to reduce new lesion occurrences and inflammatory activity. However, variability exists in disability score improvements among these studies. Observational and retrospective investigations further affirm SCT's potential, highlighting decreased relapse rates, enhanced expanded disability status scale (EDSS) scores, and a noteworthy proportion of patients achieving no evidence of disease activity (NEDA). The initial literature search using all of the search items produced a total of 3,636 articles. After title, abstract, and article type screening and article retrieving, 147 articles were assessed for eligibility using the inclusion criteria. At the end of the literature search, 37 articles met the eligibility criteria. They were included in our review according to preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Patients treated with hematopoietic stem cell transplantation (HSCT) present lower progression and relapse rates, suppression of inflammatory activity, and a greater reduction in T2 lesions on MRI than those treated with disease-modifying therapies (DMTs). In summary, while SCT presents promise as a therapeutic option for MS, its deployment should be tailored to individual patient characteristics, disease stages, and responses.

Should autologous hematopoietic stem cell transplantation be offered as a first-line disease modifying therapy to patients with multiple sclerosis?

In multiple sclerosis (MS), progression independent of new focal inflammation may commence shortly after disease onset, and it is increasingly revealed that the risk of disability accrual is reduced by early use of high-efficacy disease-modifying therapies (HE-DMTs). People with aggressive MS may therefore benefit from early treatment with autologous haematopoietic stem cell transplantation (AHSCT), a procedure inducing maximal immunosuppression followed by immune reconstitution, demonstrated to be superior to DMTs in one randomized clinical trial. However, in current practice prior failure to HE-DMTs is typically required to establish the indication for AHSCT. In the present article, the available evidence on the potential role of AHSCT as first-line treatment in aggressive MS and the rationale for its early use will be summarized. Proposed definitions of aggressive MS that could help identifying MS patients eligible for early treatment with AHSCT will also be discussed.

Effect of the COVID-19 pandemic on disease activity in multiple sclerosis patients treated with hematopoietic stem cell transplantation

BACKGROUND AND PURPOSE

It is still debated whether the COVID-19 pandemic affected disease activity in people with autoimmune diseases, including multiple sclerosis (MS). The aim of this study, therefore, was to explore the impact of COVID-19 in people with MS (pwMS) not receiving continuative disease-modifying therapy (DMT) after previous treatment with autologous hematopoietic stem cell transplantation (AHSCT).

MATERIALS AND METHODS

We included pwMS treated with AHSCT who were in disease remission without receiving DMTs during the pandemic and who were followed up at our centre during the study period. Data on SARS-CoV-2 infection and vaccination were recorded, with details of adverse events and clinical-radiological disease activity.

RESULTS

A total of 36 pwMS (31 females; 86%) were included, of whom 23 (64%) had relapsing-remitting (RR-MS) and 13 had secondary progressive MS (SP-MS). Thirty-three pwMS (92%) received anti-SARS-CoV-2 mRNA vaccines. Thirteen patients (36%) developed mild to moderate COVID-19 a median (range) of 58 (4-224) months after AHSCT; seven (54%) of these patients were not yet vaccinated. Transient neurological symptoms after vaccination or infection were reported in 9% and 36% of the patients, respectively. The rate of new inflammatory events (relapses or asymptomatic magnetic resonance imaging [MRI] activity) after AHSCT increased from 0.006 (one asymptomatic new lesion/159 patient-years) before the pandemic to 0.083 (five relapses plus two cases of asymptomatic MRI activity/84 patient-years) since the pandemic start (p = 0.004).

CONCLUSIONS

People with MS with a history of highly active disease, who are untreated or receiving moderate-efficacy DMTs might be more vulnerable to disease reactivation, possibly elicited by exogenous triggers. Careful monitoring and further investigation are warranted to ascertain whether special precautions are needed in these cases.

Autologous haematopoietic stem cell transplantation for multiple sclerosis: a position paper and registry outline

Background

While substantial progress has been made in the development of disease-modifying medications for multiple sclerosis (MS), a high percentage of treated patients still show progression and persistent inflammatory activity. Autologous haematopoietic stem cell transplantation (AHSCT) aims at eliminating a pathogenic immune repertoire through intense short-term immunosuppression that enables subsequent regeneration of a new and healthy immune system to re-establish immune tolerance for a long period of time. A number of mostly open-label, uncontrolled studies conducted over the past 20 years collected about 4000 cases. They uniformly reported high efficacy of AHSCT in controlling MS inflammatory disease activity, more markedly beneficial in relapsing-remitting MS. Immunological studies provided evidence for qualitative immune resetting following AHSCT. These data and improved safety profiles of transplantation procedures spurred interest in using AHSCT as a treatment option for MS.

Objective

To develop expert consensus recommendations on AHSCT in Germany and outline a registry study project.

Methods

An open call among MS neurologists as well as among experts in stem cell transplantation in Germany started in December 2021 to join a series of virtual meetings.

Results

We provide a consensus-based opinion paper authored by 25 experts on the up-to-date optimal use of AHSCT in managing MS based on the Swiss criteria. Current data indicate that patients who are most likely to benefit from AHSCT have relapsing-remitting MS and are young, ambulatory and have high disease activity. Treatment data with AHSCT will be collected within the German REgistry Cohort of autologous haematopoietic stem CeLl trAnsplantation In MS (RECLAIM).

Conclusion

Further clinical trials, including registry-based analyses, are urgently needed to better define the patient characteristics, efficacy and safety profile of AHSCT compared with other high-efficacy therapies and to optimally position it as a treatment option in different MS disease stages.

Haematopoietic Stem Cell Transplantation for the Treatment of Multiple Sclerosis: Recent Advances

PURPOSE OF REVIEW

Autologous haematopoietic stem cell transplantation (AHSCT) is increasingly considered a treatment option for patients with multiple sclerosis (MS), an autoimmune demyelinating and degenerative disease of the central nervous system (CNS). AHSCT persistently suppresses inflammation and improves the disease course in large proportions of patients with relapsing-remitting (RR) MS. Aim of this article is to review the relevant new knowledge published during the last 3 years.

RECENT FINDINGS

Laboratory studies reported confirmatory and new insights into the immunological and biomarker effects of AHSCT. Retrospective clinical studies confirmed excellent outcomes in RRMS, showing possible superior effectiveness over standard therapies and suggesting a possible benefit in early secondary progressive (SP) MS with inflammatory features. New data on risks of infertility and secondary autoimmunity were also reported. Further evidence on the high effectiveness and acceptable safety of AHSCT strengthens its position as a clinical option for aggressive RRMS. Further research is needed to better define its role in treatment-naïve and progressive forms of MS, ideally within randomised clinical trials (RCTs).

Hematopoietic Stem Cell Transplantation in People With Active Secondary Progressive Multiple Sclerosis

BACKGROUND AND OBJECTIVES

Uncontrolled evidence suggests that autologous hematopoietic stem cell transplantation (AHSCT) can be effective in people with active secondary progressive multiple sclerosis (SPMS). In this study, we compared the effect of AHSCT with that of other anti-inflammatory disease-modifying therapies (DMTs) on long-term disability worsening in active SPMS.

METHODS

We collected data from the Italian Bone Marrow Transplantation Study Group and the Italian Multiple Sclerosis Register. Patients were considered eligible if treatment had been started after the diagnosis of SPMS. Disability worsening was assessed by the cumulative proportion of patients with a 6-month confirmed disability progression (CDP) according to the Expanded Disability Status Scale (EDSS) score. Key secondary endpoints were the EDSS time trend after treatment start and the prevalence of disability improvement over time. Time to first CDP was assessed by means of proportional hazard Cox regression models. A linear mixed model with a time × treatment group interaction was used to assess the longitudinal EDSS time trends. Prevalence of improvement was estimated using a modified Kaplan-Meier estimator and compared between groups by bootstrapping the area under the curve.

RESULTS

Seventy-nine AHSCT-treated patients and 1975 patients treated with other DMTs (beta interferons, azathioprine, glatiramer-acetate, mitoxantrone, fingolimod, natalizumab, methotrexate, teriflunomide, cyclophosphamide, dimethyl fumarate, and alemtuzumab) were matched to reduce treatment selection bias using propensity score and overlap weighting approaches. Time to first CDP was significantly longer in transplanted patients (hazard ratio [HR] = 0.50; 95% CI = 0.31-0.81; p = 0.005), with 61.7% of transplanted patients free from CPD at 5 years. Accordingly, EDSS time trend over 10 years was higher in patients treated with other DMTs than in AHSCT-treated patients (+0.157 EDSS points per year compared with -0.013 EDSS points per year; interaction p < 0.001). Patients who underwent AHSCT were more likely to experience a sustained disability improvement: 34.7% of patients maintained an improvement (a lower EDSS than baseline) 3 years after transplant vs 4.6% of patients treated by other DMTs (p < 0.001).

DISCUSSION

The use of AHSCT in people with active SPMS is associated with a slowing of disability progression and a higher likelihood of disability improvement compared with standard immunotherapy.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that autologous hematopoietic stem cell transplants prolonged the time to CDP compared with other DMTs.

[Multiple sclerosis: interventions to halt disease : Which patients can be considered for autologous stem cell transplantation]

BACKGROUND

Autologous hematopoietic stem cell transplantation (aHSCT) for treatment of multiple sclerosis (MS) is gaining increasing prominence in the therapeutic landscape. This review article focuses on describing the evidence and European guidelines for aHSCT so that neurologists in Germany can consider this treatment option for appropriate MS patients. In this context, it must be taken into consideration that in every case a cost transfer must be individually applied for.

AIM

To provide information for neurologists considering aHSCT for patients with MS.

MATERIAL AND METHODS

In this narrative review articles from PubMed were pooled and analyzed.

RESULTS AND DISCUSSION

High quality data from randomized, controlled clinical trials are required to compare the efficacy of aHSCT to the currently available highly effective disease-modifying therapies (DMT) so that reliable conclusions can be drawn regarding the relationship between the risks and benefits of aHSCT in MS; however, the studies discussed in this review provide important points of reference for patient selection and the transplantation protocol. Further advice is available from the European Society for Blood and Marrow Transplantation (EBMT) for experienced centers considering aHSCT. The available data and the European guidelines suggest that patients aged less than 45 years, an expanded disability status scale (EDSS) ≤ 5.5, highly active MS, a disease duration of less than 10 years, an ineffective course of DMT or rapidly progressive MS may be eligible for aHSCT and should be referred to an experienced center for further assessment.

Applying stem cell therapy in intractable diseases: a narrative review of decades of progress and challenges

Background and Objective

Stem cell therapy (SCT) is one of the vastly researched branches of regenerative medicine as a therapeutic tool to treat incurable diseases. With the use of human stem cells such as embryonic stem cells (ESCs), adult stem cells (ASCs) and induced pluripotent stem cells (iPSCs), stem cell therapy aims to regenerate or repair damaged tissues and congenital defects. As stem cells are able to undergo infinite self-renewal, differentiate into various types of cells and secrete protective paracrine factors, many researchers have investigated the potential of SCT in regenerative medicine. Therefore, this review aims to provide a comprehensive review on the recent application of SCT in various intractable diseases, namely, haematological diseases, neurological diseases, diabetes mellitus, retinal degenerative disorders and COVID-19 infections along with the challenges faced in the clinical translation of SCT.

Methods

An extensive search was conducted on Google scholar, PubMed and Clinicaltrials.gov using related keywords. Latest articles on stem cell therapy application in selected diseases along with their challenges in clinical applications were selected.

Key content and findings

In vitro and in vivo studies involving SCT are shown to be safe and efficacious in treating various diseases covered in this review. There are also a number of small-scale clinical trials that validated the positive therapeutic outcomes of SCT. Nevertheless, the effectiveness of SCT are highly variable as some SCT works best in patients with early-stage diseases while in other diseases, SCT is more likely to work in patients in late stages of illnesses. Among the challenges identified in SCT translation are uncertainty in the underlying stem cell mechanism, ethical issues, genetic instability and immune rejection.

Conclusions

SCT will be a revolutionary treatment in the future that will provide hope to patients with intractable diseases. Therefore, studies ought to be done to ascertain the long-term effects of SCT while addressing the challenges faced in validating SCT for clinical use. Moreover, as there are many studies investigating the safety and efficacy of SCT, future studies should look into elucidating the regenerative and reparative capabilities of stem cells which largely remains unknown.

Autologous Hematopoietic Stem-Cell Transplantation in Multiple Sclerosis: A Systematic Review and Meta-Analysis

INTRODUCTION

In 1995, the use of autologous hematopoietic stem-cell transplantation (AHSCT), which was previously used to treat hematological tumors, was introduced for severe autoimmune diseases such as multiple sclerosis (MS). AHSCT has proven its safety over the past few years due to technical advances and careful patient selection in transplant centers. While most studies have reported that AHSCT led to decreased Expanded Disability Status Scale (EDSS) scores, some patients reported increased EDSS scores following the procedure. Given the contradictory results, we aimed to conduct a comprehensive systematic review and meta-analysis to investigate the efficacy and safety of AHSCT.

METHODS

PubMed, Web of Science, and Scopus were searched in March 2022 using a predefined search strategy. We included cohort studies, clinical trials, case-control studies, and case series that investigated the efficacy or safety of AHSCT in patients with MS. PICO in the present study was defined as follows: problem or study population (P): patients with MS; intervention (I): AHSCT; comparison (C): none; outcome (O): efficacy and safety.

RESULTS

After a two-step review process, 50 studies with a total of 4831 patients with MS were included in our study. Our analysis showed a significant decrease in EDSS score after treatment (standardized mean difference [SMD]: -0.48, 95% CI -0.75, -0.22). Moreover, the annualized relapse rate was also significantly reduced after AHSCT compared to the pretreatment period (SMD: -1.58, 95% CI -2.34, -0.78). The pooled estimate of progression-free survival after treatment was 73% (95% CI 69%, 77). Furthermore, 81% of patients with MS who received AHSCT remained relapse-free (95% CI 76%, 86%). Investigating event-free survival, which reflects the absence of any disease-related event, showed a pooled estimate of 63% (95% CI 54%, 73%). Also, the MRI activity-free survival was 89% (95% CI 84%) among included studies with low heterogeneity. New MRI lesions seem to appear in nearly 8% of patients who underwent AHSCT (95% CI 4%, 12%). Our meta-analysis showed that 68% of patients with MS experience no evidence of disease activity (NEDA) after AHSCT (95% CI 59%, 77). The overall survival after transplantation was 94% (95% CI 91%, 96%). In addition, 4% of patients died from transplant-related causes (95% CI 2%, 6%).

CONCLUSION

Current data encourages a broader application of AHSCT for treating patients with MS while still considering proper patient selection and transplant methods. In addition, with increasing knowledge and expertise in the field of stem-cell therapy, AHSCT has become a safer treatment approach for MS.

Hematopoietic stem cell transplantation and cellular therapies for autoimmune diseases: overview and future considerations from the Autoimmune Diseases Working Party (ADWP) of the European Society for Blood and Marrow Transplantation (EBMT)

Autoimmune diseases (ADs) represent a heterogenous group of complex diseases with increasing incidence in Western countries and are a major cause of morbidity. Hematopoietic stem cell transplantation (HSCT) has evolved over the last 25 years as a specific treatment for patients with severe ADs, through eradication of the pathogenic immunologic memory and profound immune renewal. HSCT for ADs is recently facing a unique developmental phase across transplant centers. This review provides a comprehensive overview of the recent evidence and developments in the area, including fundamentals of preclinical research, clinical studies in neurologic, rheumatologic and gastroenterologic diseases, which represent major indications at present, along with evidence of HSCT for rarer indications. Moreover, we describe the interwoven challenges of delivering more advanced cellular therapies, exploiting mesenchymal stem cells, regulatory T cells and potentially CAR-T cell therapies, in patients affected by ADs. Overall, we discuss past and current indications, efficacy, associated risks and benefits, and future directions of HSCT and advanced cellular therapies in the treatment of severe/refractory ADs, integrating the available literature with European Society for Blood and Marrow Transplantation (EBMT) registry data.

The current standing of autologous haematopoietic stem cell transplantation for the treatment of multiple sclerosis

Autologous haematopoietic stem cell transplantation (aHSCT) is gaining traction as a valuable treatment option for patients affected by severe multiple sclerosis (MS), particularly the relapsing–remitting form. We describe the current literature in terms of clinical trials, observational and retrospective studies, as well as immune reconstitution following transplantation, with a focus on the conditioning regimens used for transplantation. The evidence base predominantly consists of non-randomised, uncontrolled clinical trials or data from retrospective or observational cohorts, i.e. very few randomised or controlled trials. Most often, intermediate-intensity conditioning regimens are used, with promising results from both myeloablative and lymphoablative strategies, as well as from regimens that are low and high intensity. Efficacy of transplantation, which is likely secondary to immune reconstitution and restored immune tolerance, is, therefore, not clearly dependent on the intensity of the conditioning regimen. However, the conditioning regimen may well influence the immune response to transplantation. Heterogeneity of conditioning regimens among studies hinders synthesis of the articles assessing post-aHSCT immune system changes. Factors associated with better outcomes were lower Kurtzke Expanded Disability Status Scale, relapsing–remitting MS, younger age, and shorter disease duration at baseline, which supports the guidance for patient selection proposed by the European Society for Blood and Marrow Transplantation. Interestingly, promising outcomes were described for patients with secondary progressive MS by some studies, which may be worth taking into account when considering treatment options for patients with active, progressive disease. Of note, a significant proportion of patients develop autoimmune disease following transplantation, with alemtuzumab-containing regimens associated with the highest incidence.

Immune Reconstitution Following Autologous Hematopoietic Stem Cell Transplantation for Multiple Sclerosis: A Review on Behalf of the EBMT Autoimmune Diseases Working Party

Multiple sclerosis (MS) is a central nervous system (CNS) disorder, which is mediated by an abnormal immune response coordinated by T and B cells resulting in areas of inflammation, demyelination, and axonal loss. Disease-modifying treatments (DMTs) are available to dampen the inflammatory aggression but are ineffective in many patients. Autologous hematopoietic stem cell transplantation (HSCT) has been used as treatment in patients with a highly active disease, achieving a long-term clinical remission in most. The rationale of the intervention is to eradicate inflammatory autoreactive cells with lympho-ablative regimens and restore immune tolerance. Immunological studies have demonstrated that autologous HSCT induces a renewal of TCR repertoires, resurgence of immune regulatory cells, and depletion of proinflammatory T cell subsets, suggesting a "resetting" of immunological memory. Although our understanding of the clinical and immunological effects of autologous HSCT has progressed, further work is required to characterize the mechanisms that underlie treatment efficacy. Considering that memory B cells are disease-promoting and stem-like T cells are multipotent progenitors involved in self-regeneration of central and effector memory cells, investigating the reconstitution of B cell compartment and stem and effector subsets of immunological memory following autologous HSCT could elucidate those mechanisms. Since all subjects need to be optimally protected from vaccine-preventable diseases (including COVID-19), there is a need to ensure that vaccination in subjects undergoing HSCT is effective and safe. Additionally, the study of vaccination in HSCT-treated subjects as a means of evaluating immune responses could further distinguish broad immunosuppression from immune resetting.

Autologous Hematopoietic Stem Cell Transplantation in Multiple Sclerosis Patients: Monocentric Case Series and Systematic Review of the Literature

Multiple sclerosis (MS) is a chronic, inflammatory and immune-mediated disease of the central nervous system (CNS), commonly affecting young adults and potentially associated with life-long disability. About 14 disease-modifying treatments (DMTs) are currently approved for the treatment of MS. However, despite the use of highly effective therapies, some patients exhibit a highly active disease with an aggressive course from onset and a higher risk of long-term disability accrual. In the last few years, several retrospective studies, clinical trials, meta-analyses and systematic reviews have investigated autologous hematopoietic stem cell transplantation (AHSCT) as a possible therapeutic option in order to address this unmet clinical need. These studies demonstrated that AHSCT is a highly efficacious and relatively safe therapeutic option for the treatment of highly active MS. Particularly, over recent years, the amount of evidence has grown, with significant improvements in the development of patient selection criteria, choice of the most suitable transplant technique and clinical experience. In this paper, we present six patients who received AHSCT in our MS center and we systematically reviewed recent evidence about the long-term efficacy and safety of AHSCT and the placement of AHSCT in the rapidly evolving therapeutic armamentarium for MS.

Autologous hematopoietic stem cell transplantation vs low-dose immunosuppression in secondary-progressive multiple sclerosis

Background and purpose

Effectiveness of autologous haematopoietic stem cell transplantation (AHSCT) in relapsing–remitting multiple sclerosis (MS) is well known, but in secondary–progressive (SP)‐MS it is still controversial. Therefore, AHSCT activity was evaluated in SP‐MS using low‐dose immunosuppression with cyclophosphamide (Cy) as a comparative treatment.

Methods

In this retrospective monocentric 1:2 matched study, SP‐MS patients were treated with intermediate‐intensity AHSCT (cases) or intravenous pulses of Cy (controls) at a single academic centre in Florence. Controls were selected according to baseline characteristics adopting cardinality matching after trimming on the estimated propensity score. Kaplan–Meier and Cox analyses were used to estimate survival free from relapses (R‐FS), survival free from disability progression (P‐FS), and no evidence of disease activity 2 (NEDA‐2).

Results

A total of 93 SP‐MS patients were included: 31 AHSCT, 62 Cy. Mean follow‐up was 99 months in the AHSCT group and 91 months in the Cy group. R‐FS was higher in AHSCT compared to Cy patients: at Year 5, 100% versus 52%, respectively (p < 0.0001). P‐FS did not differ between the groups (at Year 5: 70% in AHSCT and 81% in Cy, p = 0.572), nor did NEDA‐2 (p = 0.379). A sensitivity analysis including only the 31 “best‐matched” controls confirmed these results. Three neoplasms (2 Cy, 1 AHSCT) and two fatalities (2 Cy) occurred.

Conclusions

This study provides Class III evidence, in SP‐MS, on the superior effectiveness of AHSCT compared to Cy on relapse activity, without differences on disability accrual. Although the suppression of relapses was observed in the AHSCT group only, AHSCT did not show advantages over Cy on disability, suggesting that in SP‐MS disability progression becomes based more on noninflammatory neurodegeneration than on inflammation.

Sustained immunotolerance in multiple sclerosis after stem cell transplant

Objective

Autologous haematopoietic stem cell transplantation (AHSCT) has the potential to induce sustained periods of disease remission in multiple sclerosis (MS), which is an inflammatory disease of the central nervous system (CNS) characterised by demyelination and axonal degeneration. However, the mechanisms associated with durable treatment responses in MS require further elucidation.

Methods

To characterise the longer term immune reconstitution effects of AHSCT at 24 and 36 months (M) post‐transplant, high‐dimensional immunophenotyping of peripheral blood mononuclear cells from 22 MS patients was performed using two custom‐designed 18‐colour flow cytometry panels.

Results

The higher baseline frequencies of specific pro‐inflammatory immune cells (T‐helper‐17 (Th17) cells, mucosal‐associated invariant T‐cells and CNS‐homing T‐conventional (T‐conv) cells observed in MS patients were decreased post‐AHSCT by 36M. This was accompanied by a post‐AHSCT increase in frequencies and absolute counts of immunoregulatory CD56^hi natural killer cells at 24M and terminally differentiated CD8⁺CD28⁻CD57⁺ cells until 36M. A sustained increase in the proportion of naïve B‐cells, with persistent depletion of memory B‐cells and plasmablasts was observed until 36M. Reconstitution of the B‐cell repertoire was accompanied by a reduction in the frequency of circulating T‐follicular helper cells (cTfh) expressing programmed cell death‐1 (PD1⁺) at 36M. Associations between frequency dynamics and clinical outcomes indicated only responder patients to exhibit a decrease in Th17, CNS‐homing T‐conv and PD1⁺ cTfh pro‐inflammatory subsets at 36M, and an increase in CD39⁺ T‐regulatory cells at 24M.

Interpretation

AHSCT induces substantial recalibration of pro‐inflammatory and immunoregulatory components of the immune system of MS patients for up to 36M post‐transplant.

Real-world application of autologous hematopoietic stem cell transplantation in 507 patients with multiple sclerosis

Objective

To investigate the results of real-world application of non-myeloablative autologous HSCT for multiple sclerosis (MS).

Methods

Between July 2003 and October 2019 at a single center (Northwestern University), 414 patients with relapsing remitting MS (RRMS) and 93 patients with newly diagnosed secondary progressive MS (SPMS) underwent non-myeloablative HSCT.

Results

There was one treatment-related death (0.19%) due to hospital-acquired legionella pneumonia, and one patient developed neutropenic bacteremia (Klebsiella pneumonia) without sepsis. Overall 5-year survival was 98.8%. Post HSCT secondary autoimmune diseases (2nd ADs) were idiopathic thrombocytopenia (ITP) and hypo or hyperthyroidism. ITP was highest with alemtuzumab (14%) and 0 to 2.8% for the non-alemtuzumab regimens. After HSCT, 16 patients developed hypothyroidism (3.5%) and 15 developed hyperthyroidism / Grave’s disease (3.3%). Relapse free survival (RFS) at 5 years for RRMS and SPMS was 80.1% and 98.1%, respectively, while progression free survival (PFS) at 4 years for RRMS and SPMS was 95% versus 66%, respectively. For patients with RRMS, the EDSS significantly improved (p < 0.0001) at each follow-up from a pre-HSCT mean of 3.87 to 2.51, 2.50, 2.41, 2.33, and 2.19 at 1, 2, 3, 4, and 5 years, respectively. For SPMS, the EDSS improved significantly only at 1 year but not thereafter. For SPMS, the mean baseline EDSS of 5.09 changed post-HSCT to 4.85 (p = 0.04), 4.88 (p = 0.2), 4.92 (p = .27), 4.72 (p = 0.07), and 4.2 (p = 0.21) at 1, 2, 3, 4, 5 years, respectively.

Conclusion

In patients with RRMS, autologous non-myeloablative HSCT is an effective one-time therapy, while HSCT appears of less benefit for newly diagnosed SPMS.

Made to Measure: Patient-Tailored Treatment of Multiple Sclerosis Using Cell-Based Therapies

Currently, there is still no cure for multiple sclerosis (MS), which is an autoimmune and neurodegenerative disease of the central nervous system. Treatment options predominantly consist of drugs that affect adaptive immunity and lead to a reduction of the inflammatory disease activity. A broad range of possible cell-based therapeutic options are being explored in the treatment of autoimmune diseases, including MS. This review aims to provide an overview of recent and future advances in the development of cell-based treatment options for the induction of tolerance in MS. Here, we will focus on haematopoietic stem cells, mesenchymal stromal cells, regulatory T cells and dendritic cells. We will also focus on less familiar cell types that are used in cell therapy, including B cells, natural killer cells and peripheral blood mononuclear cells. We will address key issues regarding the depicted therapies and highlight the major challenges that lie ahead to successfully reverse autoimmune diseases, such as MS, while minimising the side effects. Although cell-based therapies are well known and used in the treatment of several cancers, cell-based treatment options hold promise for the future treatment of autoimmune diseases in general, and MS in particular.

Stem Cell Therapies for Progressive Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system characterized by demyelination and axonal degeneration. MS patients typically present with a relapsing-remitting (RR) disease course, manifesting as sporadic attacks of neurological symptoms including ataxia, fatigue, and sensory impairment. While there are several effective disease-modifying therapies able to address the inflammatory relapses associated with RRMS, most patients will inevitably advance to a progressive disease course marked by a gradual and irreversible accrual of disabilities. Therapeutic intervention in progressive MS (PMS) suffers from a lack of well-characterized biological targets and, hence, a dearth of successful drugs. The few medications approved for the treatment of PMS are typically limited in their efficacy to active forms of the disease, have little impact on slowing degeneration, and fail to promote repair. In looking to address these unmet needs, the multifactorial therapeutic benefits of stem cell therapies are particularly compelling. Ostensibly providing neurotrophic support, immunomodulation and cell replacement, stem cell transplantation holds substantial promise in combatting the complex pathology of chronic neuroinflammation. Herein, we explore the current state of preclinical and clinical evidence supporting the use of stem cells in treating PMS and we discuss prospective hurdles impeding their translation into revolutionary regenerative medicines.

Multiple Sclerosis

Many groundbreaking advances have occurred in the field of multiple sclerosis since this series last reviewed the disorder in 2014. The U.S. Food and Drug Administration has approved 7 new medications for relapsing-remitting multiple sclerosis and approved the first medication for primary progressive multiple sclerosis. The McDonald criteria for diagnosing multiple sclerosis were updated in 2017. New blood tests can now differentiate patients with multiple sclerosis from those with neuromyelitis optica spectrum disorder, and 3 new medications have been approved specifically for the latter disorder. Also, new medications for treating the symptoms of multiple sclerosis have been introduced.

Highly effective disease-modifying treatment as initial MS therapy

PURPOSE OF REVIEW

Using highly effective (HE) compounds right from the beginning of disease-modifying immunotherapy (DMT) in people with multiple sclerosis (pwMS) has gained popularity among clinicians and pwMS alike. We discuss the most recent evidence supporting this approach, and whether any of the associated risks should stop us adopting it as a default strategy.

RECENT FINDINGS

With the addition of injectable ofatumumab, and the two oral sphingosine one phosphate modulators siponimod and ozanimod, ten HE DMTs are now available for pwMS, though variation in licensing status and cost may limit their use in some healthcare environments. Real World evidence based on large MS registry data suggests the superiority of early HE DMT over a slow treatment escalation approach; delaying HE DMT leads to more rapid and often irreversible disability accrual. Mechanistically, B-cell depletion, particularly memory B-cell suppression, is a common denominator closely associated with DMT efficacy.

SUMMARY

The concept that HE DMTs are necessarily associated with a high risk of adverse effects, is no longer supported by the evidence. The rather predictable and manageable risk profile of most HE DMTs should lower the threshold for clinicians to discuss such treatment with pwMS as a first line approach.