Survival, and time to an advanced disease state or progression, of untreated patients with moderately severe multiple sclerosis in a multicenter observational database: relevance for design of a clinical trial for high dose immunosuppressive therapy with autologous hematopoietic stem cell transplantation

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.

Repeat infusion of autologous bone marrow cells in progressive multiple sclerosis - A phase I extension study (SIAMMS II)

BACKGROUND

During the safety and feasibility 'Study of Intravenous Autologous Marrow in Multiple Sclerosis (SIAMMS)', intravenous infusion of autologous marrow was well tolerated. The efficacy of the approach is being explored in a placebo-controlled randomised controlled trial (ACTiMuS, NCT01815632) but it is not known whether repeated infusions will be required to optimise benefit. The objective of the current study was to explore the safety and feasibility of repeat treatment with intravenous autologous bone marrow for patients with progressive multiple sclerosis (MS).

METHODS

'SIAMMS II' was a prospective, single centre phase I extension study in which participants in the SIAMMS study were offered repeat bone marrow harvest and infusion of autologous, unfractionated bone marrow as a day-case procedure. The primary outcome measure was number of adverse events and secondary outcome measures included change in clinical rating scales of disability, global evoked potential and cranial magnetic resonance imaging (MRI).

RESULTS

In total, 4 of the 6 participants in the SIAMMS study had repeat bone marrow harvest and infusion of filtered autologous marrow as a day case procedure which was well tolerated. There were no serious adverse effects. Additional outcome measures including clinical scales, global evoked potentials and cranial MRI were stable.

CONCLUSION

SIAMMS II demonstrates the safety and feasibility of repeated, non-myeloablative autologous bone marrow-derived cell therapy in progressive 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.

Haematopoietic Stem Cell Transplantation for Multiple Sclerosis: Current Status

Autologous haematopoietic stem cell transplantation (AHSCT) is a treatment option for aggressive forms of multiple sclerosis (MS) that has been derived from haematological indications and repurposed for treatment of refractory autoimmune diseases. In the present review, a search for clinical studies on AHSCT was performed on the PubMed website and ClinicalTrials.gov databases. Papers were selected according to the following criteria: text written in English language, publication date between 2014 and August 2019, and reports including more than five patients. Prospective randomised and uncontrolled trials and retrospective case series were reviewed to examine the safety and efficacy of the procedure. Treatment protocols, pathological data and economic aspects of AHSCT were also succinctly covered. Growing evidence suggests that long-term suppression of inflammatory activity with stabilization or improvement of disability can be achieved in a high proportion of properly selected patients. More sophisticated outcome measures recently adopted, including effect on brain atrophy and disease biomarkers, are giving further insight into the effectiveness of transplant. The risks of the procedure have decreased to levels that can be considered acceptable for treatment of individuals with aggressive forms of MS. Careful selection of patients with an expected good benefit/risk profile, which is maximal when AHSCT is performed in early phases of the disease, and the expertise of transplant centres are critical to the success of treatment. Higher efficacy of AHSCT than with conventional treatments has recently been demonstrated by one randomised trial and further evidence is awaited from ongoing and planned trials comparing AHSCT with the most effective disease-modifying therapeutic agents.

Transition to secondary progression in relapsing-onset multiple sclerosis: Definitions and risk factors

BACKGROUND

No uniform criteria for a sensitive identification of the transition from relapsing-remitting multiple sclerosis (MS) to secondary-progressive multiple sclerosis (SPMS) are available.

OBJECTIVE

To compare risk factors of SPMS using two definitions: one based on the neurologist judgment (ND) and an objective data-driven algorithm (DDA).

METHODS

Relapsing-onset MS patients (n = 19,318) were extracted from the Italian MS Registry. Risk factors for SPMS and for reaching irreversible Expanded Disability Status Scale (EDSS) 6.0, after SP transition, were estimated using multivariable Cox regression models.

RESULTS

SPMS identified by the DDA (n = 2343, 12.1%) were older, more disabled and with a faster progression to severe disability (p < 0.0001), than those identified by the ND (n = 3868, 20.0%). In both groups, the most consistent risk factors (p < 0.05) for SPMS were a multifocal onset, an age at onset >40 years, higher baseline EDSS score and a higher number of relapses; the most consistent protective factor was the disease-modifying therapy (DMT) exposure. DMT exposure during SP did not impact the risk of reaching irreversible EDSS 6.0.

CONCLUSION

A DDA definition of SPMS identifies more aggressive progressive patients. DMT exposure reduces the risk of SPMS conversion, but it does not prevent the disability accumulation after the SP transition.

Risk of secondary progressive multiple sclerosis: A longitudinal study

Background:

The risk factors for conversion from relapsing-remitting to secondary progressive multiple sclerosis remain highly contested.

Objective:

The aim of this study was to determine the demographic, clinical and paraclinical features that influence the risk of conversion to secondary progressive multiple sclerosis.

Methods:

Patients with adult-onset relapsing–remitting multiple sclerosis and at least four recorded disability scores were selected from MSBase, a global observational cohort. The risk of conversion to objectively defined secondary progressive multiple sclerosis was evaluated at multiple time points per patient using multivariable marginal Cox regression models. Sensitivity analyses were performed.

Results:

A total of 15,717 patients were included in the primary analysis. Older age (hazard ratio (HR) = 1.02, p < 0.001), longer disease duration (HR = 1.01, p = 0.038), a higher Expanded Disability Status Scale score (HR = 1.30, p < 0.001), more rapid disability trajectory (HR = 2.82, p < 0.001) and greater number of relapses in the previous year (HR = 1.07, p = 0.010) were independently associated with an increased risk of secondary progressive multiple sclerosis. Improving disability (HR = 0.62, p = 0.039) and disease-modifying therapy exposure (HR = 0.71, p = 0.007) were associated with a lower risk. Recent cerebral magnetic resonance imaging activity, evidence of spinal cord lesions and oligoclonal bands in the cerebrospinal fluid were not associated with the risk of conversion.

Conclusion:

Risk of secondary progressive multiple sclerosis increases with age, duration of illness and worsening disability and decreases with improving disability. Therapy may delay the onset of secondary progression.

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.

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.

The role of autologous haemopoietic stem cell transplantation in the treatment of autoimmune disorders

Autologous haemopoietic stem cell transplantation (HSCT) has been used for over 30 years for malignant haematological diseases, such as myeloma and lymphoma, with considerable success. More recently this procedure has been adopted as a form of high dose immunosuppression in selected patients with autoimmune diseases that are resistant to conventional therapies. Animal models have previously outlined the rationale and validity of HSCT in patients with these non-malignant, but in many cases, life-threatening conditions. Recent data have that deletion of putative autoreactive immune clones with reconstitution of a thymic driven, tolerant immune system occurs in HSCT for auto-immune patients. Two randomised control trials have confirmed that HSCT is superior to monthly cyclophosphamide in systemic sclerosis with a highly significant disease free and overall survival benefit demonstrated in the Autologous Stem cell Transplantation International Scleroderma trial. Over 2000 patients worldwide with autoimmune conditions have been treated with HSCT - the commonest indications being multiple sclerosis (MS) and systemic sclerosis. Encouraging relapse free survival of 70-80% at 4 years, in heavily pre-treated MS patients, has been demonstrated in Phase II trials. A Phase III trial in MS patients who have failed interferon is currently accruing patients. Future challenges include improvements in safety of HSCT, particularly in cardiac assessment of systemic sclerosis patients, cost-benefit analyses of HSCT compared to standard therapy and establishment of centres of excellence to continue to enhance the safety and benefit of this exciting new therapy.

High-dose chemotherapy and multiple sclerosis

PURPOSE OF REVIEW

Immunomodulatory medications for multiple sclerosis provide only modest control of this potentially debilitating auto-immune disease of the central nervous system. The immunosuppression provided by high-dose chemotherapy has been studied to address treatment-refractory disease. In this review, we discuss the recent significant work in this field and its associated controversies.

RECENT FINDINGS

Conclusive evidence for the efficacy of high-dose chemotherapy with stem cell rescue is lacking given the lack of uniform patient populations and varying treatment protocols. Moreover, the significant toxicity associated with this procedure has dampened enthusiasm for its widespread use. High-dose chemotherapy without stem cell rescue has been trialed as a less toxic approach that eliminates the possibility of re-infusing autoreactive lymphocytes found in the stem cell product.

SUMMARY

Before high-dose chemotherapy with or without stem cell rescue can be adopted for clinical practice, both approaches require testing in randomized clinical trials. Both procedures have the possibility of decreasing disease activity but high-dose chemotherapy without stem cell rescue having a more favorable safety profile, may prove a more significant advance in the field of high-dose therapy for multiple sclerosis.

Autologous hematopoietic stem cell transplantation in autoimmune diseases

The term 'autoimmune diseases' encompasses a spectrum of diseases whose clinical manifestations and, possibly, biological features vary widely. The results of conventional treatment are considered unsatisfactory in aggressive forms, with subsets of patients having short life expectancies. Relying on wide experimental evidence and more feeble clinical data, some research groups have used autologous hematopoietic stem cell transplantation (HSCT) in the most disabling autoimmune diseases with the aim of resetting the patient's immune system. Immunoablative conditioning regimens are preferred over their myeloablative counterparts, and some form of in vivo and/or ex vivo T-cell depletion is generally adopted. Despite 15 years' experience, published controlled clinical trials are still lacking, with the evidence so far available coming from pilot studies and registry surveys. In multiple sclerosis, clinical improvement, or at least lasting disease stabilization, can be achieved in the majority of the patients; nevertheless, the worst results are observed in patients with progressive disease, where no benefit can be expected from conventional therapy. Concerning rheumatologic diseases, wide experience has been acquired in systemic sclerosis, with long-term improvements in cutaneous disease being frequently reported, although visceral involvement remains unchanged at best. Autografting has proved to be barely effective in rheumatoid arthritis and quite toxic in juvenile idiopathic arthritis, whereas it leads to clinical remission and the reversal of visceral impairment in the majority of patients with systemic lupus erythematosus. A promising indication is Crohn's disease, in which long-term endoscopic remission is frequently observed. Growing experience with autologous HCST in autoimmune diseases has progressively reduced concerns about transplant-related mortality and secondary myelodysplasia/leukemia. Therefore, a sustained complete remission seems to be within the reach of autografting in some autoimmune diseases; in others, the indications, risks and benefits of autografting need to be better defined. Consequently, the search for new drugs should also be encouraged.

Therapeutic approaches to multiple sclerosis: an update on failed, interrupted, or inconclusive trials of immunomodulatory treatment strategies

Multiple sclerosis (MS) continues to be a therapeutic challenge, and much effort is being made to develop new and more effective immune therapies. Particularly in the past decade, neuroimmunologic research has delivered new and highly effective therapeutic options, as seen in the growing number of immunotherapeutic agents and biologics in development. However, numerous promising clinical trials have failed to show efficacy or have had to be halted prematurely because of unexpected adverse events. Some others have shown results that are of unknown significance with regard to a reliable assessment of true efficacy versus safety. For example, studies of the highly innovative monoclonal antibodies that selectively target immunologic effector molecules have not only revealed the impressive efficacy of such treatments, they have also raised serious concerns about the safety profiles of these antibodies. These results add a new dimension to the estimation of risk-benefit ratios regarding acute or long-term adverse effects. Therapeutic approaches that have previously failed in MS have indicated that there are discrepancies between theoretical expectations and practical outcomes of different compounds. Learning from these defeats helps to optimize future study designs and to reduce the risks to patients. This review summarizes trials on MS treatments since 2001 that failed or were interrupted, attempts to analyze the underlying reasons for failure, and discusses the implications for our current view of MS pathogenesis, clinical practice, and design of future studies. In order to maintain clarity, this review focuses on anti-inflammatory therapies and does not include studies on already approved and effective disease-modifying therapies, albeit used in distinct administration routes or under different paradigms. Neuroprotective and alternative treatment strategies are presented elsewhere.

Autologous haematopoietic stem-cell transplantation in multiple sclerosis

Intense immunosuppression followed by autologous haematopoietic stem-cell transplantation has been assessed over the past few years as a possible new therapeutic strategy in severe forms of multiple sclerosis. Pioneering studies began in 1995, and since then, more than 400 patients worldwide have been treated with this procedure. Small uncontrolled studies show that about 60-70% of treated cases do not progress in the follow-up period of at least 3 years. Transplant-related mortality, which was 5-6% in the first reported series, has reduced in the past 5 years to 1-2%. Relapses dramatically decrease and inflammatory MRI activity is almost completely suppressed. Autologous haematopoietic stem-cell transplantation is associated with qualitative immunological changes in the blood, suggesting that, beyond its immunosuppressive potential, it could also have some beneficial effect for the resetting of the immune system. Patients with severe, rapidly worsening multiple sclerosis who are unresponsive to approved therapies could be candidates for this treatment, but its clinical efficacy has still to be shown in large, prospective, controlled studies.

Reducing the probability of false positive research findings by pre-publication validation - experience with a large multiple sclerosis database

BACKGROUND

Published false positive research findings are a major problem in the process of scientific discovery. There is a high rate of lack of replication of results in clinical research in general, multiple sclerosis research being no exception. Our aim was to develop and implement a policy that reduces the probability of publishing false positive research findings. We have assessed the utility to work with a pre-publication validation policy after several years of research in the context of a large multiple sclerosis database.

METHODS

The large database of the Sylvia Lawry Centre for Multiple Sclerosis Research was split in two parts: one for hypothesis generation and a validation part for confirmation of selected results. We present case studies from 5 finalized projects that have used the validation policy and results from a simulation study.

RESULTS

In one project, the "relapse and disability" project as described in section II (example 3), findings could not be confirmed in the validation part of the database. The simulation study showed that the percentage of false positive findings can exceed 20% depending on variable selection.

CONCLUSION

We conclude that the validation policy has prevented the publication of at least one research finding that could not be validated in an independent data set (and probably would have been a "true" false-positive finding) over the past three years, and has led to improved data analysis, statistical programming, and selection of hypotheses. The advantages outweigh the lost statistical power inherent in the process.

Extensive Hippocampal Demyelination in Multiple Sclerosis

Memory impairment is especially prominent within the spectrum of cognitive deficits in multiple sclerosis (MS), and a crucial role for hippocampal pathology may therefore be expected in this disease. This study is the first to systematically assess hippocampal demyelination in MS. Hippocampal tissue samples of 19 chronic MS cases and 7 controls with non-neurologic disease were stained immunohistochemically for myelin proteolipid protein. Subsequently, number, location, and size of demyelinated lesions were assessed. Furthermore, the specimens were stained for HLA-DR to investigate microglia/macrophage activity. An unexpectedly high number of lesions (n = 37) was found in 15 of the 19 MS cases. Mixed intrahippocampal-perihippocampal lesions, which were more often found in cases with cognitive decline, were large and did not respect anatomical borders. Moderate microglial activation was frequently observed at the edges of these mixed lesions. Isolated intrahippocampal lesions were also frequently found. These were smaller than the mixed lesions and had a specific anatomical predilection: the cornu ammonis 2 subregion and the hilus of the dentate gyrus were consistently spared. Microglial activation was rare in isolated intrahippocampal lesions. Our results indicate that hippocampal demyelination is frequent and extensive in MS and that anatomical localization, size, and inflammatory activity vary for different lesion types.

Microchimerism and Stem Cell Transplantation in Multiple Sclerosis

Scientific advances have demonstrated that autoreactive cells are a component of the healthy immune repertoire. If we define autoimmunity as an active induction of autoreaction, the solution should be an active induction of self-tolerance, and may indicate the direction to explore the future therapies. Microchimerism (MC) refers to the presence of a limited number of nonhost cells in the body of an individual. These cells can enter via blood transfusion and organ transplantation or naturally through pregnancy. Chimeric cells engraft in the host body, develop, proliferate, and are accepted by the immune system as self. These include stem cells that enter the maternal body during fetal stages. These stem cells are also postulated to be helpful reservoirs in protecting the host body. MC has been considered a risk factor in autoimmune disease induction. However, today we know it is a natural phenomenon. MC can be considered a natural model of successful transplantation, the earliest engrafting cells being fetal mesenchymal stem cells (MSCs). MSCs have two notable features. They have an immunosuppressive quality when encountering the adoptive immune system and they display repair-inducing potential within damaged tissues. For the fetus, MC appears to be an effective factor in maternal tolerance induction toward the fetal graft and for the mother; these novel fetal cells might be useful in disease conditions occurring after pregnancy. Hematopoietic stem cell transplantation has become an accepted treatment option for both malignant and nonmalignant diseases and this unique procedure is now being investigated as a potential therapy for multiple sclerosis (MS). Due to the dichotomous properties of MSC, suppressing aggressive immune dysfunction while promoting damaged tissue repair, they may be appropriate therapy for MS.