Long-term results of stem cell transplantation for MS: a single-center experience

Autologous hematopoietic stem cell transplantation for multiple sclerosis: Long-term follow-up data from Norway

BACKGROUND

Autologous hematopoietic stem cell transplantation (HSCT) is a potent treatment option for patients with aggressive relapsing-remitting multiple sclerosis (RRMS).

OBJECTIVE

To evaluate long-term outcomes of HSCT in MS.

METHODS

National retrospective single-center observational study of patients with aggressive RRMS that underwent HSCT in Norway from January 2015 to January 2018. Criteria for receiving HSCT included at least two clinical relapses the last year while on disease modifying treatment (DMT).

RESULTS

In total, 29 patients, with a mean follow-up time of 70 months (standard deviation:14.3), were evaluated. Twenty patients (69%) had sustained no evidence of disease activity (NEDA-3) status, 24 (83%) were relapse-free, 23 (79%) free of magnetic resonance imaging (MRI) activity, and 26 (90%) free of progression. Number of patients working full-time increased from 1 (3%), before HSCT, to 10 (33%) after 2 years and 15 (52%) after 5 years.

CONCLUSION

HSCT offers long-term disease-free survival with successively increasing work participation in patients with aggressive MS resistant to DMTs.

Autologous hematopoietic stem cell transplantation of patients with aggressive relapsing-remitting multiple sclerosis: Danish nation-wide experience

BACKGROUND

Autologous hematopoietic stem cell treatment (AHSCT) is considered an effective treatment option for patients with aggressive relapsing-remitting multiple sclerosis (RRMS). Still there are few randomized and controlled studies of AHSCT to shed light on the safety and efficacy of the treatment, and therefore experiences from single centers are important.

AIM

To describe the Danish experience with AHSCT regarding patient characteristics, safety, and efficacy.

METHOD

Nationwide retrospective single center study of patients with multiple sclerosis (MS) treated with AHSCT.

RESULTS

A total of 32 patients were treated with AHSCT from May 2011 to May 2021. Seven were treated with carmustine, etoposide, cytarabine arabinoside, and melphalan (BEAM) as well as antithymocyte globulin (ATG). Twenty-five patients were treated with cyclophosphamide (CY) and ATG. In the whole cohort, relapse-free survival (RFS) was 77% (95% CI: 64-94%), worsening-free survival (WFS) was 79% (95% CI: 66-96%), MRI event-free survival (MFS) was 93% (95% CI: 85-100%), and no evidence of disease (NEDA-3) was 69% (95% CI: 54-89%) at the end of year two post-AHSCT. We had no treatment related mortality and only few severe adverse events (AEs).

CONCLUSION

AHSCT of patients with aggressive RRMS was an effective and relatively safe treatment with few serious AEs and no mortality in Danish patients.

The Use of Stem Cells as a Potential Treatment Method for Selected Neurodegenerative Diseases: Review

Stem cells have been the subject of research for years due to their enormous therapeutic potential. Most neurological diseases such as multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD) are incurable or very difficult to treat. Therefore new therapies are sought in which autologous stem cells are used. They are often the patient's only hope for recovery or slowing down the progress of the disease symptoms. The most important conclusions arise after analyzing the literature on the use of stem cells in neurodegenerative diseases. The effectiveness of MSC cell therapy has been confirmed in ALS and HD therapy. MSC cells slow down ALS progression and show early promising signs of efficacy. In HD, they reduced huntingtin (Htt) aggregation and stimulation of endogenous neurogenesis. MS therapy with hematopoietic stem cells (HSCs) inducted significant recalibration of pro-inflammatory and immunoregulatory components of the immune system. iPSC cells allow for accurate PD modeling. They are patient-specific and therefore minimize the risk of immune rejection and, in long-term observation, did not form any tumors in the brain. Extracellular vesicles derived from bone marrow mesenchymal stromal cells (BM-MSC-EVs) and Human adipose-derived stromal/stem cells (hASCs) cells are widely used to treat AD. Due to the reduction of Aβ42 deposits and increasing the survival of neurons, they improve memory and learning abilities. Despite many animal models and clinical trial studies, cell therapy still needs to be refined to increase its effectiveness in the human body.

Stem-Cell-Based Therapy: The Celestial Weapon against Neurological Disorders

Stem cells are a versatile source for cell therapy. Their use is particularly significant for the treatment of neurological disorders for which no definitive conventional medical treatment is available. Neurological disorders are of diverse etiology and pathogenesis. Alzheimer's disease (AD) is caused by abnormal protein deposits, leading to progressive dementia. Parkinson's disease (PD) is due to the specific degeneration of the dopaminergic neurons causing motor and sensory impairment. Huntington's disease (HD) includes a transmittable gene mutation, and any treatment should involve gene modulation of the transplanted cells. Multiple sclerosis (MS) is an autoimmune disorder affecting multiple neurons sporadically but induces progressive neuronal dysfunction. Amyotrophic lateral sclerosis (ALS) impacts upper and lower motor neurons, leading to progressive muscle degeneration. This shows the need to try to tailor different types of cells to repair the specific defect characteristic of each disease. In recent years, several types of stem cells were used in different animal models, including transgenic animals of various neurologic disorders. Based on some of the successful animal studies, some clinical trials were designed and approved. Some studies were successful, others were terminated and, still, a few are ongoing. In this manuscript, we aim to review the current information on both the experimental and clinical trials of stem cell therapy in neurological disorders of various disease mechanisms. The different types of cells used, their mode of transplantation and the molecular and physiologic effects are discussed. Recommendations for future use and hopes are highlighted.

[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.

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.

New autoimmune diseases after autologous hematopoietic stem cell transplantation for multiple sclerosis

Secondary autoimmune diseases (2ndADs), most frequently autoimmune cytopenias (AICs), were first described after allogeneic hematopoietic stem cell transplantation (HSCT) undertaken for malignant and hematological indications, occurred at a prevalence of ~5-6.5%, and were attributed to allogeneic immune imbalances in the context of graft versus host disease, viral infections, and chronic immunosuppression. Subsequently, 2ndADs were reported to complicate roughly 2-14% of autologous HSCTs performed for an autoimmune disease. Alemtuzumab in the conditioning regimen has been identified as a risk for development of 2ndADs after either allogeneic or autologous HSCT and is consistent with the high rates of 2ndADs when using alemtuzumab as monotherapy. Due to the significant consequences but variable incidence, depending on conditioning regimen, of 2ndADs and similarity in known immune reconstitution kinetics after autologous HSCT for autoimmune diseases and after alemtuzumab monotherapy, we propose that an imbalance between B and T lineage regeneration early after HSCT may underlie the pathogenesis of 2ndADs.

Autologous Hematopoietic Stem Cell Transplantation (AHSCT): An Evolving Treatment Avenue in Multiple Sclerosis

Autologous hematopoietic stem cell transplantation (AHSCT) is considered as the novel approach to improve multiple sclerosis (MS) patients with disease-modifying therapies (DMTs)-resistance. The results obtained from different studies indicate that AHSCT increases the life quality of MS patients. Several factors are known to be influenced on the successful rate of AHSCT in patients with MS. The individuals aged <40 years with a short duration of MS disease have been demonstrated to show a better response to AHSCT administration. Furthermore, this treatment approach was more effective in relapsing remitting MS (RRMS) patients than progressive MS (PMS). Different clinical trials revealed that AHSCT with a low density conditioning regimen could be suggested as a suitable candidate approach in the management of MS. Several molecular and cellular mechanisms are known to be involved in the resetting of the immune system following the AHSCT infusion in MS patients. These mechanisms play a role in the depletion of auto-reactive lymphocytes and immune system renewal. In the present review, we discuss different clinical and molecular aspects of AHSCT application in the alleviation of MS symptoms.

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

OBJECTIVE

To determine whether autologous hematopoietic stem cell transplantation (aHSCT) is able to induce durable disease remission in people with multiple sclerosis (MS), we analyzed the long-term outcomes after transplantation in a large cohort of patients with MS.

METHODS

To be included, a minimum dataset (consisting of age, MS phenotype, Expanded Disability Status Scale [EDSS] score at baseline, information on transplantation technology, and at least 1 follow-up visit after transplantation) was required.

RESULTS

Two hundred ten patients were included (relapsing-remitting [RR] MS 122 [58%]). Median baseline EDSS score was 6 (1-9); mean follow-up was 6.2 (±5.0) years. Among patients with RRMS, disability worsening-free survival (95% confidence interval [CI]) was 85.5% (76.9%-94.1%) at 5 years and 71.3% (57.8%-84.8%) at 10 years. In patients with progressive MS, disability worsening-free survival was 71.0% (59.4%-82.6%) and 57.2% (41.8%-72.7%) at 5 and 10 years, respectively. In patients with RRMS, EDSS significantly reduced after aHSCT (p = 0.001; mean EDSS change per year -0.09 [95% CI -0.15% to -0.04%]). In patients with RRMS, the use of the BCNU+Etoposide+Ara-C+Melphalan (BEAM) + anti-thymocyte globulin (ATG) conditioning protocol was independently associated with a reduced risk of no evidence of disease activity 3 failure (hazard ratio 0.27 [95% CI 0.14-0.50], p < 0.001). Three patients died within 100 days from aHSCT (1.4%); no deaths occurred in patients transplanted after 2007.

CONCLUSIONS

aHSCT prevents disability worsening in the majority of patients and induces durable improvement in disability in patients with RRMS. The BEAM + ATG conditioning protocol is associated with a more pronounced suppression of clinical relapses and MRI inflammatory activity.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that for people with MS, aHSCT induces durable disease remission in most patients.

Autologous haematopoietic stem cell transplantation as a first-line disease-modifying therapy in patients with 'aggressive' multiple sclerosis

BACKGROUND

Autologous haematopoietic stem cell transplantation (AHSCT) is an effective treatment for patients with multiple sclerosis (MS) who have highly active disease, despite the use of standard disease-modifying therapies (DMTs). However, the optimal time for offering AHSCT to patients with 'aggressive' MS is yet to be established.

OBJECTIVES

The objective was to explore the safety and efficacy of AHSCT as a first-line DMT in patients with 'aggressive' MS.

METHODS

All patients with 'aggressive' MS who received AHSCT as a first-line DMT in five European and North American centres were retrospectively evaluated.

RESULTS

Twenty patients were identified. The median interval between diagnosis and AHSCT was 5 (1-20) months. All had multiple poor prognostic markers with a median pre-transplant Expanded Disability Status Scale (EDSS) score of 5.0 (1.5-9.5). After a median follow-up of 30 (12-118) months, the median EDSS score improved to 2.0 (0-6.5, p < 0.0001). No patient had further relapses. Three had residual magnetic resonance imaging (MRI) disease activities in the first 6 months post-transplant, but no further new or enhancing lesions were observed in subsequent scans.

CONCLUSION

AHSCT is safe and effective as a first-line DMT in inducing rapid and sustained remission in patients with 'aggressive' MS.

A review of hematopoietic stem cell transplantation for autoimmune diseases: multiple sclerosis, systemic sclerosis and Crohn's disease. Position paper of the Brazilian Society of Bone Marrow Transplantation

Autoimmune diseases are an important field for the development of bone marrow transplantation, or hematopoietic stem cell transplantation. In Europe alone, almost 3000 procedures have been registered so far. The Brazilian Society for Bone Marrow Transplantation (Sociedade Brasileira de Transplantes de Medula Óssea) organized consensus meetings for the Autoimmune Diseases Group, to review the available literature on hematopoietic stem cell transplantation for autoimmune diseases, aiming to gather data that support the procedure for these patients. Three autoimmune diseases for which there are evidence-based indications for hematopoietic stem cell transplantation are multiple sclerosis, systemic sclerosis and Crohn's disease. The professional stem cell transplant societies in America, Europe and Brazil (Sociedade Brasileira de Transplantes de Medula Óssea) currently consider hematopoietic stem cell transplantation as a therapeutic modality for these three autoimmune diseases. This article reviews the evidence available.

Hematopoietic Stem Cell Transplantation for Autoimmune Disease

The introduction of targeted biologic therapies has changed the treatment landscape for autoimmune diseases (ADs) substantially, but although these therapies provide more specificity, they require continuous administration, rarely restore organ function or reverse disability, and are not curative. Over the last 25 years, hematopoietic stem cell transplantation (HSCT) has been increasingly used to treat patients in whom the risk:benefit ratio of HSCT is acceptable. In contrast to chronic suppression of immune function, this intensive one-off procedure aims to provide treatment-free remissions by the reinduction of self-tolerance. The European Society for Blood and Marrow Transplantation (EBMT) Autoimmune Diseases Working Party (ADWP) has been central to development of this approach, with over 3,300 HSCT registrations for ADs. Recent data have improved the evidence base to support autologous HSCT in multiple sclerosis, systemic sclerosis, and Crohn's disease, along with a wide range of rarer disease indications, and autologous HSCT has become an integral part of treatment algorithms in various ADs.

Autologous Haematopoietic Stem Cell Transplantation in Multiple Sclerosis: a Review of Current Literature and Future Directions for Transplant Haematologists and Oncologists

Purpose of Review

We summarise the current development of autologous haematopoietic stem cell transplantation (AHSCT) in treating multiple sclerosis (MS) and discuss future directions for the general neurologist, transplant haematologist and oncologist.

Recent Findings

AHSCT was initially performed to treat MS over 20 years ago. Over recent years, the evidence base has grown, especially in relapsing-remitting MS (RRMS), with significant improvements in safety and efficacy through better patient selection, choice of transplant technique and increase in centre experience.

Summary

AHSCT is now a treatment option in very carefully selected patients with severe, treatment-resistant RRMS. However, it is important for transplant haematologists and oncologists to work closely with specialist MS neurologists in patient selection, during transplant and in long-term follow-up of patients. Data should be registered into international transplant registries and, ideally, patients should be enrolled on prospective clinical trials in order to build the evidence base and refine transplant techniques.

Intensive immunosuppression followed by autologous hematopoietic stem cell transplantation for the treatment of multiple sclerosis

Autologous hematopoietic stem cell transplantation (AHSCT) to treat multiple sclerosis (MS) has mostly been used in devastating cases as the last option to stop further neurological deterioration. However, evidence from several retrospective clinical trials indicates that young, less disabled patients with highly inflammatory active MS are the most likely to benefit from AHSCT, and after moving from high-intensity to nonmyeloablative procedures the tolerability of AHSCT has increased and its associated risk and mortality have declined considerably. Recent meta-analyses and randomized clinical trials show that AHSCT is more effective than currently approved disease-modifying therapies (DMTs), with suppression of disease activity in 70-90% of patients and long-term cessation of disease activity in two-thirds of treated patients. The rationale for AHSCT is to eliminate autoimmunity and achieve immune resetting by intense immunosuppression followed by infusion of autologous hematopoietic stem cells. Similar effects on the immune system have been suggested for cladribine and alemtuzumab treatment and, together with AHSCT, they constitute the induction or immune-reconstitution therapies for MS. Although, further randomized controlled trials of AHSCT for MS are needed, it has become clear that improved patient selection and lower intensity conditioning regimens have reduced AHSCT associated risks and mortality and strengthened the position of AHSCT among other DMTs. Do we have enough experience and scientific support for AHSCT in MS to move from an exclusive treatment for aggressive, treatment-resistant MS and acquire broader indications, similar to other effective DMTs?

Clinical neurorestorative cell therapies: Developmental process, current state and future prospective

Clinical cell therapies (CTs) for neurological diseases and cellular damage have been explored for more than 2 decades. According to the United States Food and Drug Administration, there are 2 types of cell categories for therapy, namely stem cell-derived CT products and mature/functionally differentiated cell-derived CT products. However, regardless of the type of CT used, the majority of reports of clinical CTs from either small sample sizes based on single-center phase 1 or 2 unblinded trials or retrospective clinical studies showed effects on neurological improvement and the ability to either partially or temporarily thwart the deteriorating cellular processes of the neurodegenerative diseases. There have been only a few prospective, multicenter, randomized, double- blind placebo-control clinical trials of CTs so far in this developing novel area that have shown negative results, and more clinical trials are needed. This will expand our knowledge in exploring the type of cells that yield promising results and restore damaged neurological structure and functions of the central nervous system based on higher level evidence-based medical data. In this review, we briefly introduce the developmental process, current state, and future prospective for clinical neurorestorative CT.

Safety and efficacy of autologous hematopoietic stem cell transplantation for multiple sclerosis in Norway

Background:

Hematopoietic stem cell treatment (HSCT) is a promising treatment option for multiple sclerosis (MS), but detailed safety and efficacy measures are still scarce.

Objective:

To evaluate the efficacy and safety of HSCT in MS.

Methods:

Retrospective single-center observational study of all MS patients that underwent HSCT in Norway during January 2015 to January 2018. The primary outcome was no evidence of disease activity (NEDA-3) status.

Results:

A total of 30 patients with a median follow-up time of 26 months (range: 11–48) were evaluated. In total, 25 (83%) achieved NEDA-3 status, and none received disease-modifying treatment after HSCT. For 13 (43%) of the patients, there were sustained improvement in Expanded Disability Status Scale (EDSS) score, and 10 (33%) were working full time after the treatment, compared to only 1 (3%) before treatment. There were no serious treatment-related complications and was no mortality. Five patients (17%) were diagnosed with an autoimmune thyroid disease after the procedure, and 10 (43%) of the women had amenorrhea lasting >12 months and symptoms of ovarian failure.

Conclusion:

HSCT in MS is an effective and relatively safe treatment option, with few serious complications and no mortality in Norway, so far. However, long-term adverse event with amenorrhea is a common problem.

Autologous Hematopoietic Cell Transplantation in Multiple Sclerosis: Changing Paradigms in the Era of Novel Agents

Autologous hematopoietic stem cell transplantation (AHSCT) is established as a standard of care for diseases ranging from hematological malignancies to other neoplastic pathologies and severe immunological deficiencies. In April 1995, our group performed the first AHSCT in progressive multiple sclerosis (MS). Since then, a plethora of studies have been published with encouraging but controversial results. Major challenges in the field include appropriate patient selection, improvements in AHSCT procedure, and timing of this treatment modality. Beyond AHSCT, several new intravenous or oral agents have been developed and approved over the last 20 years in MS. The emergence of multiple effective therapies for MS has created a challenging scenario for both treating physicians and patients. Novel cell-based therapies other than AHSCT are also currently investigated in MS patients with promising results. Our review is aimed at summarizing state-of-the-art knowledge on basic principles and results of AHSCT in MS and its role compared to novel agents.

Stem Cell-Based Therapies for Multiple Sclerosis: Current Perspectives

Multiple sclerosis (MS) is an inflammatory and neurodegenerative autoimmune disease of the central nervous system (CNS). Disease-modifying therapies (DMT) targeting inflammation have been shown to reduce disease activity in patients with relapsing–remitting MS (RRMS). The current therapeutic challenge is to find an effective treatment to halt disease progression and reverse established neural damage. Stem cell-based therapies have emerged to address this dilemma. Several types of stem cells have been considered for clinical use, such as autologous hematopoietic (aHSC), mesenchymal (MSC), neuronal (NSC), human embryonic (hESC), and induced pluripotent (iPSC) stem cells. There is convincing evidence that immunoablation followed by hematopoietic therapy (aHSCT) has a high efficacy for suppressing inflammatory MS activity and improving neurological disability in patients with RRMS. In addition, MSC therapy may be a safe and tolerable treatment, but its clinical value is still under evaluation. Various studies have shown early promising results with other cellular therapies for CNS repair and decreasing inflammation. In this review, we discuss the current knowledge and limitations of different stem cell-based therapies for the treatment of patients with MS.

Autologous haematopoietic stem cell transplantation for neurological diseases

Neuroinflammatory diseases such as multiple sclerosis, neuromyelitis optica, chronic inflammatory demyelinating polyneuropathy and myasthenia gravis are leading causes of physical disability in people of working age. In the last decades significant therapeutic advances have been made that can ameliorate the disease course. Nevertheless, many affected will continue to deteriorate despite treatment, and the costs associated with disease-modifying drugs constitute a significant fiscal burden on healthcare in developed countries. Autologous haematopoietic stem cell transplantation is a treatment approach that aims to ameliorate and to terminate disease activity. The erroneous immune system is eradicated using cytotoxic drugs, and with the aid of haematopoietic stem cells a new immune system is rebuilt. As of today, more than 1000 patients with multiple sclerosis have been treated with this procedure. Available data suggest that autologous haematopoietic stem cell transplantation is superior to conventional treatment in terms of efficacy with an acceptable safety profile. A smaller number of patients with other neuroinflammatory conditions have been treated with promising results. Herein, current data on clinical effect and safety of autologous haematopoietic stem cell transplantation for neurological disease are reviewed.

Long-term follow-up more than 10 years after HSCT: a monocentric experience

BACKGROUND

Autologous hematopoietic stem cell transplantation (aHSCT) is used in aggressive relapsing and progressive multiple sclerosis (MS). The multicentre studies and case series reported have relatively short follow-up.

AIM

To evaluate long-term effect and safety of HSCT in MS.

MATERIALS AND METHODS

Patients referred to the MS centre of Cagliari and undergoing HSCT were included. Variations in relapses and EDSS before and after HSCT were evaluated by Wilcoxon test. A descriptive analysis was made for other clinical data.

RESULTS

Nine patients (female 6, males 3; 5 relapsing-remitting, 2 secondary progressive, 1 primary progressive, and 1 progressive relapsing) performed HSCT (1999-2006). The median follow-up was 11 years (11-18). Eight patients underwent aHSCT, seven using a low intensity conditioning regimen, and one an intermediate intensity. The primary progressive underwent allogeneic HSCT, due to onco hematological disease. The relapses number decreased in the 2 years following the procedure compared to the two preceding years (p = 0.041). New relapses or disease progressions were observed after a range of 7 (low intensity regimen)-118 (intermediate intensity) months. At last follow-up, the EDSS was stable in two patients, improved in two, and worse in five (maximum 2 EDSS in one patient). Six patients showed new lesions, and seven gadolinium-enhancing on brain MRI after a mean of 23.3 and 19.8 months, respectively. Two serious adverse events were reported: melanoma, and progressive multifocal leukoencephalopathy.

CONCLUSIONS AND DISCUSSION

Our results confirm in a long follow-up the efficacy of HSCT in reducing relapses and disability progression. The risk/benefit profile is better for intermediate intensity regimens.

[Indications and follow-up for autologous hematopoietic stem cell transplantation in autoimmune and autoinflammatory diseases: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]

The Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) organized the 7th allogeneic hematopoietic stem cell transplantation clinical practices harmonization workshop series in September 2017 in Lille, France and updated recommendations for indications and follow-up in autologous hematopoietic stem cell transplantation in autoimmune and autoinflammatory diseases, previously published under the auspices of SFGM-TC.

Intense immunosuppression followed by autologous haematopoietic stem cell transplantation as a therapeutic strategy in aggressive forms of multiple sclerosis

In the majority of relapsing multiple sclerosis patients, the disease can be quite easily controlled by already available, approved therapies. There are, however, some aggressive cases who continue to have clinical and magnetic resonance imaging (MRI) activity in spite of the treatment. These are the cases who may now receive benefit from intense immunosuppression followed by autologous haematopoietic stem cell transplantation (aHSCT). In this review, we describe the method and the rationale of aHSCT, the more recently published studies that demonstrate its efficacy in selected multiple sclerosis cases, the problems related to safety and the transplant-related mortality risk of the procedure. A description of the ideal patient who can take advantage of aHSCT is outlined and, finally, the ongoing studies which are near to completion or are close to starting are briefly reported.

Autologous haematopoietic stem cell transplantation for treatment of multiple sclerosis

Autologous haematopoietic stem cell transplantation (AHSCT) is a multistep procedure that enables destruction of the immune system and its reconstitution from haematopoietic stem cells. Originally developed for the treatment of haematological malignancies, the procedure has been adapted for the treatment of severe immune-mediated disorders. Results from ∼20 years of research make a compelling case for selective use of AHSCT in patients with highly active multiple sclerosis (MS), and for controlled trials. Immunological studies support the notion that AHSCT causes qualitative immune resetting, and have provided insight into the mechanisms that might underlie the powerful treatment effects that last well beyond recovery of immune cell numbers. Indeed, studies have demonstrated that AHSCT can entirely suppress MS disease activity for 4-5 years in 70-80% of patients, a rate that is higher than those achieved with any other therapies for MS. Treatment-related mortality, which was 3.6% in studies before 2005, has decreased to 0.3% in studies since 2005. Current evidence indicates that the patients who are most likely to benefit from and tolerate AHSCT are young, ambulatory and have inflammatory MS activity. Clinical trials are required to rigorously test the efficacy, safety and cost-effectiveness of AHSCT against highly active MS drugs.

Cell Therapy for Multiple Sclerosis

Cell therapy is considered a promising potential treatment for multiple sclerosis, perhaps particularly for the progressive form of the disease for which there are currently no useful treatments. Over the past two decades or more, much progress has been made in understanding the biology of MS and in the experimental development of cell therapy for this disease. Three quite distinct forms of cell therapy are currently being pursued. The first seeks to use stem cells to replace damaged myelin-forming oligodendrocytes within the CNS; the second aims, in effect, to replace the individual's misfunctioning immune system, making use of haematopoietic stem cells; and the third seeks to utilise endogenous stem cell populations by mobilisation with or without in vitro expansion, exploiting their various reparative and neuroprotective properties. In this article we review progress in these three separate areas, summarising the experimental background and clinical progress thus far made.

Long-term Outcomes After Autologous Hematopoietic Stem Cell Transplantation for Multiple Sclerosis

Importance

Autologous hematopoietic stem cell transplantation (AHSCT) may be effective in aggressive forms of multiple sclerosis (MS) that fail to respond to standard therapies.

Objective

To evaluate the long-term outcomes in patients who underwent AHSCT for the treatment of MS in a large multicenter cohort.

Design, Setting, and Participants

Data were obtained in a multicenter, observational, retrospective cohort study. Eligibility criteria were receipt of AHSCT for the treatment of MS between January 1995 and December 2006 and the availability of a prespecified minimum data set comprising the disease subtype at baseline; the Expanded Disability Status Scale (EDSS) score at baseline; information on the administered conditioning regimen and graft manipulation; and at least 1 follow-up visit or report after transplant. The last patient visit was on July 1, 2012. To avoid bias, all eligible patients were included in the analysis regardless of their duration of follow-up. Data analysis was conducted from September 1, 2014 to April 27, 2015.

Exposures

Demographic, disease-related, and treatment-related exposures were considered variables of interest, including age, disease subtype, baseline EDSS score, number of previous disease-modifying treatments, and intensity of the conditioning regimen.

Main Outcomes and Measures

The primary outcomes were MS progression-free survival and overall survival. The probabilities of progression-free survival and overall survival were calculated using Kaplan-Meier survival curves and multivariable Cox proportional hazards regression analysis models.

Results

Valid data were obtained from 25 centers in 13 countries for 281 evaluable patients, with median follow-up of 6.6 years (range, 0.2-16 years). Seventy-eight percent (218 of 281) of patients had progressive forms of MS. The median EDSS score before mobilization of peripheral blood stem cells was 6.5 (range, 1.5-9). Eight deaths (2.8%; 95% CI, 1.0%-4.9%) were reported within 100 days of transplant and were considered transplant-related mortality. The 5-year probability of progression-free survival as assessed by the EDSS score was 46% (95% CI, 42%-54%), and overall survival was 93% (95% CI, 89%-96%) at 5 years. Factors associated with neurological progression after transplant were older age (hazard ratio [HR], 1.03; 95% CI, 1.00-1.05), progressive vs relapsing form of MS (HR, 2.33; 95% CI, 1.27-4.28), and more than 2 previous disease-modifying therapies (HR, 1.65; 95% CI, 1.10-2.47). Higher baseline EDSS score was associated with worse overall survival (HR, 2.03; 95% CI, 1.40-2.95).

Conclusions and Relevance

In this observational study of patients with MS treated with AHSCT, almost half of them remained free from neurological progression for 5 years after transplant. Younger age, relapsing form of MS, fewer prior immunotherapies, and lower baseline EDSS score were factors associated with better outcomes. The results support the rationale for further randomized clinical trials of AHSCT for the treatment of MS.

Autologous hematopoietic stem cell transplantation in multiple sclerosis

Objective:

To summarize the evidence on immunoablative therapy followed by autologous hematopoietic stem cell transplantation (aHSCT) to manage severe and treatment-refractory multiple sclerosis (MS).

Methods:

We collected all the published studies of aHSCT in any form of MS from 1995 to 2016, carefully excluding reports that were updated in subsequent studies. Endpoints were transplant-related mortality (TRM), rate of disease progression, and no evidence of disease activity (NEDA) status. A weighted metaregression based on a Poisson model was run, assessing whether there were study-specific characteristics with an effect on TRM and progression.

Results:

Fifteen studies including 764 transplanted patients were pooled in the meta-analysis. The pooled estimate of TRM was 2.1% (95% confidence interval [CI] 1.3%–3.4%). TRM was higher in older studies (p = 0.014) and in studies with a lower proportion of patients with relapsing-remitting MS (RRMS) (p = 0.028). A higher baseline Expanded Disability Status Scale (p = 0.013) was also significantly associated with a higher TRM. Pooled rate of progression was 17.1% at 2 years (95% CI 9.7%–24.5%) and 23.3% (95% CI 16.3%–31.8%) at 5 years. Lower 2-year progression rate was significantly associated with higher proportions of patients with RRMS (p = 0.004). The pooled proportion of NEDA patients at 2 years was 83% (range 70%–92%) and at 5 years was 67% (range 59%–70%).

Conclusions:

The emerging evidence on this therapeutic approach in MS indicates that the largest benefit/risk profile form this therapeutic approach can be obtained in patients with aggressive MS with a relapsing-remitting course and who have not yet accumulated a high level of disability.

Autologous hematopoietic stem cell transplantation in relapsing-remitting multiple sclerosis: comparison with secondary progressive multiple sclerosis

The main objective of our work is to describe the long-term results of myeloablative autologous hematopoietic stem cell transplant (AHSCT) in multiple sclerosis patients. Patients that failed to conventional therapies for multiple sclerosis (MS) underwent an approved protocol for AHSCT, which consisted of peripheral blood stem cell mobilization with cyclophosphamide and granulocyte colony-stimulating factor (G-CSF), followed by a conditioning regimen of BCNU, Etoposide, Ara-C, Melphalan IV, plus Rabbit Thymoglobulin. Thirty-eight MS patients have been transplanted since 1999. Thirty-one patients have been followed for more than 2 years (mean 8.4 years). There were 22 relapsing-remitting multiple sclerosis (RRMS) patients and 9 secondary progressive multiple sclerosis (SPMS) patients. No death related to AHSCT. A total of 10 patients (32.3%) had at least one relapse during post-AHSCT evolution, 6 patients in the RRMS group (27.2%) and 4 in the SPMS group (44.4%). After AHSCT, 7 patients (22.6%) experienced progression of disability, all within SP form. By contrast, no patients with RRMS experienced worsening of disability after a median follow-up of 5.4 years, 60% of them showed a sustained reduction in disability (SRD), defined as the improvement of 1.0 point in the expanded disability status scale (EDSS) sustains for 6 months (0.5 in cases of EDSS ≥ 5.5). The only clinical variable that predicted a poor response to AHSCT was a high EDSS in the year before transplant. AHSCT using the BEAM-ATG scheme is safe and efficacious to control the aggressive forms of RRMS.

Lymphocyte reconstitution following autologous stem cell transplantation for progressive MS

BACKGROUND

Autologous stem cell transplantation (ASCT) for progressive multiple sclerosis (MS) may reset the immune repertoire.

OBJECTIVE

The objective of this paper is to analyse lymphocyte recovery in patients with progressive MS treated with ASCT.

METHODS

Patients with progressive MS not responding to conventional treatment underwent ASCT following conditioning with high-dose cyclophosphamide and antithymocyte globulin. Lymphocyte subset analysis was performed before ASCT and for two years following ASCT. Neurological function was assessed by the EDSS before ASCT and for three years post-ASCT.

RESULTS

CD4+ T-cells fell significantly post-transplant and did not return to baseline levels. Recent thymic emigrants and naïve T-cells fell sharply post-transplant but returned to baseline by nine months and twelve months, respectively. T-regulatory cells declined post-transplant and did not return to baseline levels. Th1 and Th2 cells did not change significantly while Th17 cells fell post-transplant but recovered to baseline by six months. Neurological function remained stable in the majority of patients. Progression-free survival was 69% at three years.

CONCLUSION

This study demonstrates major changes in the composition of lymphocyte subsets following ASCT for progressive MS. In particular, ablation and subsequent recovery of thymic output is consistent with the concept that ASCT can reset the immune repertoire in MS patients.

High-dose immunosuppressive therapy and autologous HCT for relapsing-remitting MS

OBJECTIVE

To evaluate the safety, efficacy, and durability of multiple sclerosis (MS) disease stabilization after high-dose immunosuppressive therapy (HDIT) and autologous hematopoietic cell transplantation (HCT).

METHODS

High-Dose Immunosuppression and Autologous Transplantation for Multiple Sclerosis (HALT-MS) is a phase II clinical trial of HDIT/HCT for patients with relapsing-remitting (RR) MS who experienced relapses with disability progression (Expanded Disability Status Scale [EDSS] 3.0-5.5) while on MS disease-modifying therapy. The primary endpoint was event-free survival (EFS), defined as survival without death or disease activity from any one of: disability progression, relapse, or new lesions on MRI. Participants were evaluated through 5 years posttransplant. Toxicities were reported using the National Cancer Institute Common Terminology Criteria for Adverse Events (AE).

RESULTS

Twenty-five participants were evaluated for transplant and 24 participants underwent HDIT/HCT. Median follow-up was 62 months (range 12-72). EFS was 69.2% (90% confidence interval [CI] 50.2-82.1). Progression-free survival, clinical relapse-free survival, and MRI activity-free survival were 91.3% (90% CI 74.7%-97.2%), 86.9% (90% CI 69.5%-94.7%), and 86.3% (90% CI 68.1%-94.5%), respectively. AE due to HDIT/HCT were consistent with expected toxicities and there were no significant late neurologic adverse effects noted. Improvements were noted in neurologic disability with a median change in EDSS of -0.5 (interquartile range -1.5 to 0.0; p = 0.001) among participants who survived and completed the study.

CONCLUSION

HDIT/HCT without maintenance therapy was effective for inducing long-term sustained remissions of active RRMS at 5 years.

CLINICALTRIALSGOV IDENTIFIER

NCT00288626.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that participants with RRMS experienced sustained remissions with toxicities as expected from HDIT/HCT.

Autologous Bone Marrow Transplantation in Multiple Sclerosis: Biomarker Relevance for Patient Recruitment and Follow up

BACKGROUND

Despite the current availability of disease modifying therapies for the treatment of multiple sclerosis, there are still patients who suffer from severe neurological dysfunction in the relapsing-remitting or early progressive forms of the disease. For these patients autologous hematopoietic stem cell transplant offers an important therapeutic solution to prevent progression to irreversible disability. In spite of multiple studies in the last two decades, patient inclusion criteria, protocols for peripheral blood stem cell mobilization and bone marrow cell conditioning and methodology of follow up for autologous hematopoietic stem cell transplant in multiple sclerosis have not been strictly unified.

METHODS

We reviewed five recent clinical studies that confirmed the positive outcome of transplant in spite of disclosing significant differences in methodology of enrollment including patient disease subtypes, disease duration range, disability, regimens of peripheral blood stem cell mobilization and bone marrow cell conditioning, scheduling of imaging studies after transplant, and absence of laboratory biomarkers consistently applied to these studies.

RESULTS

Therapy with autologous hematopoietic stem cell transplant has shown best results among young individuals with severe relapsing-remitting or early progressive disease through its ability to maintain no evidence of disease activity status in a significantly higher proportion of patients after transplant in comparison to patients treated with disease modifying therapies. Important cross-sectional differences in the reviewed studies were found.

CONCLUSION

A specific and careful selection of biomarkers, based on the current physiopathological mechanisms known to result in multiple sclerosis, will contribute to a better and earlier patient selection for autologous hematopoietic stem cell transplant and follow up process. An objective and measurable response could be obtained with the determination of biomarkers at the onset of treatment and after follow-up on reconstitution of the immune response. The application of such parameters could also help further our understanding of pathogenesis of the disease.

Immunoablation and autologous haemopoietic stem-cell transplantation for aggressive multiple sclerosis: a multicentre single-group phase 2 trial

BACKGROUND

Strong immunosuppression, including chemotherapy and immune-depleting antibodies followed by autologous haemopoietic stem-cell transplantation (aHSCT), has been used to treat patients with multiple sclerosis, improving control of relapsing disease. We addressed whether near-complete immunoablation followed by immune cell depleted aHSCT would result in long-term control of multiple sclerosis.

METHODS

We did this phase 2 single-arm trial at three hospitals in Canada. We enrolled patients with multiple sclerosis, aged 18-50 years with poor prognosis, ongoing disease activity, and an Expanded Disability Status Scale of 3.0-6.0. Autologous CD34 selected haemopoietic stem-cell grafts were collected after mobilisation with cyclophosphamide and filgrastim. Immunoablation with busulfan, cyclophosphamide, and rabbit anti-thymocyte globulin was followed by aHSCT. The primary outcome was multiple sclerosis activity-free survival (events were clinical relapse, appearance of a new or Gd-enhancing lesion on MRI, and sustained progression of Expanded Disability Status Scale score). This study was registered at ClinicalTrials.gov, NCT01099930.

FINDINGS

Between diagnosis and aHSCT, 24 patients had 167 clinical relapses over 140 patient-years with 188 Gd-enhancing lesions on 48 pre-aHSCT MRI scans. Median follow-up was 6.7 years (range 3.9-12.7). The primary outcome, multiple sclerosis activity-free survival at 3 years after transplantation was 69.6% (95% CI 46.6-84.2). With up to 13 years of follow-up after aHSCT, no relapses occurred and no Gd enhancing lesions or new T2 lesions were seen on 314 MRI sequential scans. The rate of brain atrophy decreased to that expected for healthy controls. One of 24 patients died of transplantation-related complications. 35% of patients had a sustained improvement in their Expanded Disability Status Scale score.

INTERPRETATION

We describe the first treatment to fully halt all detectable CNS inflammatory activity in patients with multiple sclerosis for a prolonged period in the absence of any ongoing disease-modifying drugs. Furthermore, many of the patients had substantial recovery of neurological function despite their disease's aggressive nature.

FUNDING

Multiple Sclerosis Scientific Research Foundation.

The role of stem cell therapy in multiple sclerosis: An overview of the current status of the clinical studies

The complexity of multiple sclerosis (MS) and the incompetence of a large number of promised treatments for MS urge us to plan new and more effective therapeutic approaches that aim to suppress ongoing autoimmune responses and induction of local endogenous regeneration. Emerging data propose that hematopoietic, mesenchymal, and neural stem cells have the potential to restore self-tolerance, provide in situ immunomodulation and neuroprotection, as well as promote regeneration. Thus, in this article, we will first provide an overview of the cell sources for proposed mechanisms that contribute to the beneficial effects of stem cell transplantation, the ideal route and/or timing of stem cell-based therapies for each main stem cell group, and finally, an overview of the current status of stem cell research in clinical trial stages in MS by comparable and healthy therapeutic effects of different stem cell therapies for MS patients.

Hematopoietic stem cell transplantation for multiple sclerosis: is it a clinical reality?

Hematopoietic stem cell transplantation (HSCT) is a treatment paradigm that has long been utilized for cancers of the blood and bone marrow but has gained some traction as a treatment paradigm for multiple sclerosis (MS). Success in the treatment of patients with this approach has been reported primarily when strict inclusion criteria are imposed that have eventuated a more precise understanding of MS pathophysiology, thereby governing trial design. Moreover, enhancing the yield and purity of hematopoietic stem cells during isolation along with the utility of appropriate conditioning agents has provided a clearer foundation for clinical translation studies. To support this approach, preclinical data derived from animal models of MS, experimental autoimmune encephalomyelitis, have provided clear identification of multipotent stem cells that can reconstitute the immune system to override the autoimmune attack of the central nervous system. In this review, we will discuss the rationale of HSCT to treat MS by providing the benefits and complications of the clinically relevant protocols, the varying graft types, and conditioning regimens. However, we emphasize that future trials based on HSCT should be focused on specific therapeutic strategies to target and limit ongoing neurodegeneration and demyelination in progressive MS, in the hope that such treatment may serve a greater catchment of patient cohorts with potentially enhanced efficiency and lower toxicity. Despite these future ambitions, a proposed international multicenter, randomized clinical trial of HSCT should be governed by the best standard care of treatment, whereby MS patients are selected upon strict clinical course criteria and long-term follow-up studies of patients from international registries are imposed to advocate HSCT as a therapeutic option in the management of MS.

Therapeutic Advances and Future Prospects in Progressive Forms of Multiple Sclerosis

Identifying effective therapies for the treatment of progressive forms of multiple sclerosis (MS) is a highly relevant priority and one of the greatest challenges for the global MS community. Better understanding of the mechanisms involved in progression of the disease, novel trial designs, drug repurposing strategies, and new models of collaboration may assist in identifying effective therapies. In this review, we discuss various therapies under study in phase II or III trials, including antioxidants (idebenone); tyrosine kinase inhibitors (masitinib); sphingosine receptor modulators (siponimod); monoclonal antibodies (anti-leucine-rich repeat and immunoglobulin-like domain containing neurite outgrowth inhibitor receptor-interacting protein-1, natalizumab, ocrelizumab, intrathecal rituximab); hematopoetic stem cell therapy; statins and other possible neuroprotective agents (amiloride, riluzole, fluoxetine, oxcarbazepine); lithium; phosphodiesterase inhibitors (ibudilast); hormone-based therapies (adrenocorticotrophic hormone and erythropoietin); T-cell receptor peptide vaccine (NeuroVax); autologous T-cell immunotherapy (Tcelna); MIS416 (a microparticulate immune response modifier); dopamine antagonists (domperidone); and nutritional supplements, including lipoic acid, biotin, and sunphenon epigallocatechin-3-gallate (green tea extract). Given ongoing and planned clinical trial initiatives, and the largest ever focus of the global research community on progressive MS, future prospects for developing targeted therapeutics aimed at reducing disability in progressive forms of MS appear promising.

Autologous hematopoietic stem cell transplantation in progressive severe multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of central nervous system (CNS), which is disabling and majorly involves younger population. Various available treatments in forms of immunomodulation are not very effective; however, stem cell transplantation seems to be promising in recent literature. The current case report is a novel evidence for autologous hematopoietic stem cell transplantation (HSCT) in progressive MS.

CASE SUMMARY

A 33 year old male with secondary progressive MS (SPMS), after being failed and/or intolerance to standard approved interferon (IFN) and mitoxantrone therapy, autologous HSCT was administered. At 2years of post-stem cell transplantation follow-up, he has remained stable with some improvement in functional status (Expanded Disability Status Scale (EDSS) reduced by 1.5), with no relapse, no treatment related complications, and no fresh magnetic resonance imaging (MRI) lesions.

CONCLUSION

Autologous stem cell transplantation may be beneficial in progressive forms of MS, but needs to be tested in well-designed randomized trial.

Balancing Early Aggression Against Risk of Progression in Multiple Sclerosis

Multiple sclerosis is a chronic demyelinating disease characterized by focal and diffuse inflammation of the central nervous system resulting in significant physical and cognitive disabilities. Disease-modifying therapies targeting the dysfunctional immune response are most effective in the first few years after disease onset, indicating that there is a limited time window for therapy to influence the disease course. No evidence of disease activity is emerging as a new standard for treatment response and may be associated with improved long-term disability outcomes. An aggressive management strategy, including earlier use of more potent immunomodulatory agents and close monitoring of the clinical and radiologic response to treatment, is recommended to minimize early brain volume loss and slow the progression of physical and cognitive impairments in patients with relapsing-remitting multiple sclerosis.

Autologous bone marrow transplantation for the treatment of multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system and represents one of the leading causes of neurologic disability in young adults. Current treatments for MS have shown limited efficacy in patients with either a progressive or an aggressive disease course. Hematopoietic stem cell transplantation (HSCT) has been proposed to control or even cure refractory cases of MS. Indeed, HSCT is able to temporarily eradicate the autoreactive cells and to reset the aberrant immune response to self-antigens. In the last decade, owing to the growing experience in selecting the most appropriate patients to transplant and the recent advances in chemotherapeutic and support regimens, the transplant-related mortality of autologous HSCT in MS patients dropped down to 1,3 % and the progression-free survival ranges from 47 % to 100 %. Altogether, these data support autologous HSCT as a possible second-line therapy for refractory MS.

High-dose immunosuppressive therapy and autologous hematopoietic cell transplantation for relapsing-remitting multiple sclerosis (HALT-MS): a 3-year interim report

IMPORTANCE

Most patients with relapsing-remitting (RR) multiple sclerosis (MS) who receive approved disease-modifying therapies experience breakthrough disease and accumulate neurologic disability. High-dose immunosuppressive therapy (HDIT) with autologous hematopoietic cell transplant (HCT) may, in contrast, induce sustained remissions in early MS.

OBJECTIVE

To evaluate the safety, efficacy, and durability of MS disease stabilization through 3 years after HDIT/HCT.

DESIGN, SETTING, AND PARTICIPANTS

Hematopoietic Cell Transplantation for Relapsing-Remitting Multiple Sclerosis (HALT-MS) is an ongoing, multicenter, single-arm, phase 2 clinical trial of HDIT/HCT for patients with RRMS who experienced relapses with loss of neurologic function while receiving disease-modifying therapies during the 18 months before enrolling. Participants are evaluated through 5 years after HCT. This report is a prespecified, 3-year interim analysis of the trial. Thirty-six patients with RRMS from referral centers were screened; 25 were enrolled.

INTERVENTIONS

Autologous peripheral blood stem cell grafts were CD34+ selected; the participants then received high-dose treatment with carmustine, etoposide, cytarabine, and melphalan as well as rabbit antithymocyte globulin before autologous HCT.

MAIN OUTCOMES AND MEASURES

The primary end point of HALT-MS is event-free survival defined as survival without death or disease activity from any one of the following outcomes: (1) confirmed loss of neurologic function, (2) clinical relapse, or (3) new lesions observed on magnetic resonance imaging. Toxic effects are reported using National Cancer Institute Common Terminology Criteria for Adverse Events.

RESULTS

Grafts were collected from 25 patients, and 24 of these individuals received HDIT/HCT. The median follow-up period was 186 weeks (interquartile range, 176-250) weeks). Overall event-free survival was 78.4% (90% CI, 60.1%-89.0%) at 3 years. Progression-free survival and clinical relapse-free survival were 90.9% (90% CI, 73.7%-97.1%) and 86.3% (90% CI, 68.1%-94.5%), respectively, at 3 years. Adverse events were consistent with expected toxic effects associated with HDIT/HCT, and no acute treatment-related neurologic adverse events were observed. Improvements were noted in neurologic disability, quality-of-life, and functional scores.

CONCLUSIONS AND RELEVANCE

At 3 years, HDIT/HCT without maintenance therapy was effective for inducing sustained remission of active RRMS and was associated with improvements in neurologic function. Treatment was associated with few serious early complications or unexpected adverse events.

Autologous haematopoietic stem cell transplantation for aggressive multiple sclerosis: the Swedish experience

BACKGROUND

Autologous haematopoietic stem cell transplantation (HSCT) is a viable option for treatment of aggressive multiple sclerosis (MS). No randomised controlled trial has been performed, and thus, experiences from systematic and sustained follow-up of treated patients constitute important information about safety and efficacy. In this observational study, we describe the characteristics and outcome of the Swedish patients treated with HSCT for MS.

METHODS

Neurologists from the major hospitals in Sweden filled out a follow-up form with prospectively collected data. Fifty-two patients were identified in total; 48 were included in the study and evaluated for safety and side effects; 41 patients had at least 1 year of follow-up and were further analysed for clinical and radiological outcome. In this cohort, 34 patients (83%) had relapsing-remitting MS, and mean follow-up time was 47 months.

RESULTS

At 5 years, relapse-free survival was 87%; MRI event-free survival 85%; expanded disability status scale (EDSS) score progression-free survival 77%; and disease-free survival (no relapses, no new MRI lesions and no EDSS progression) 68%. Presence of gadolinium-enhancing lesions prior to HSCT was associated with a favourable outcome (disease-free survival 79% vs 46%, p=0.028). There was no mortality. The most common long-term side effects were herpes zoster reactivation (15%) and thyroid disease (8.4%).

CONCLUSIONS

HSCT is a very effective treatment of inflammatory active MS and can be performed with a high degree of safety at experienced centres.

Future treatment approaches to multiple sclerosis

The modern treatment era for multiple sclerosis (MS) began in 1993 with the approval of the first disease-modifying agent. Since then the field has greatly expanded, with 10 therapies currently approved to treat MS. These treatments are effective to reduce relapses and changes on MRI, and slow disability. However, despite these medications some patients continue to have exacerbations, accumulate disability, and develop progressive disease due to partial effectiveness. New molecules with novel mechanisms of action and targets are being explored. Hopefully these agents will yield even greater efficacy without significant safety concerns. As more aggressive therapies are available to treat MS, the goals and expectations of treatment are also likely to change. Some of the emerging therapies, including alemtuzumab, daclizumab, rituximab, ocrelizumab, laquinimod, estriol, 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins), vitamin D, and stem cell transplantation, will be discussed in this chapter. In the future, therapies with different mechanisms may be combined, but this will need to be evaluated in clinical trials. Neuroprotection and repair definitely warrant further study. The future of MS treatment is very exciting, especially as our armamentarium expands.