High dose cyclophosphamide preferentially targets naïve T (CD45/CD4/RA+) cells in CIDP and MS patients

Cyclophosphamide for Treatment of Refractory Chronic Inflammatory Demyelinating Polyradiculoneuropathy: A Systematic Review and Meta-analysis

PURPOSE

This study evaluates the tolerability and efficacy of cyclophosphamide (CYC) for the treatment of refractory chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

METHODS

We searched PubMed, Embase, Cochrane Library, and 2 Chinese databases (Chinese National Knowledge Infrastructure and SinoMed) for studies published between database inception and September 30, 2021. Articles obtained using the appropriate keywords were independently selected by 2 reviewers on the basis of the established inclusion and exclusion criteria.

FINDINGS

In total, 240 records that were eventually curtailed to 13 studies with 83 patients were retrieved and subsequently included in this evaluation. All 13 studies were included in the systematic review, 7 of which were included in the meta-analysis. The pooled estimate of the response rate was 68% (95% CI, 45%-90%). The pooled estimate of the adverse reaction rate was 8% (95% CI, 0%-15%). The disease duration before the first CYC treatment was negatively correlated with the reduction in the modified Rankin Scale score (r = -0.76, P < 0.001). However, the response rates did not differ significantly between patients of different sexes (P = 0.716) or between patients who received and those who did not receive concurrent glucocorticoids (P = 0.617).

IMPLICATIONS

CYC might be a recommended therapeutic option for patients with refractory CIDP, especially those who are unable to accept rituximab treatment. Earlier CYC treatment yields better therapeutic outcomes in patients with refractory CIDP without CYC-related contraindications.

Efflux Capacity and Aldehyde Dehydrogenase Both Contribute to CD8+ T-cell Resistance to Posttransplant Cyclophosphamide

CD8⁺ T cells increase drug effluxing and aldehyde dehydrogenase expression in allogeneic reactions, enhancing resistance to cyclophosphamide.

Common γ-chain cytokines and the proliferative state of the cell modulate these resistance pathways.

Mechanisms of T-cell survival after cytotoxic chemotherapy, including posttransplantation cyclophosphamide (PTCy), are not well understood. Here, we explored the impact of PTCy on human CD8⁺ T-cell survival and reconstitution, including what cellular pathways drive PTCy resistance. In major histocompatibility complex (MHC)-mismatched mixed lymphocyte culture (MLC), treatment with mafosfamide, an in vitro active cyclophosphamide analog, preserved a relatively normal distribution of naïve and memory CD8⁺ T cells, whereas the percentages of mucosal-associated invariant T (MAIT) cells and phenotypically stem cell memory (Tscm) T-cell subsets were increased. Activated (CD25⁺) and proliferating CD8⁺ T cells were derived from both naïve and memory subsets and were reduced but still present after mafosfamide. By contrast, cyclosporine-A (CsA) or rapamycin treatment preferentially maintained nonproliferating CD25⁻ naïve cells. Drug efflux capacity and aldehyde dehydrogenase-1A1 expression were increased in CD8⁺ T cells in allogeneic reactions in vitro and in patients, were modulated by common γ-chain cytokines and the proliferative state of the cell, and contributed to CD8⁺ T-cell survival after mafosfamide. The CD8⁺ T-cell composition early after hematopoietic cell transplantation (HCT) in PTCy-treated patients was dominated by CD25⁺ and phenotypically memory, including Tscm and MAIT, cells, consistent with MLC. Yet, MHC-mismatched murine HCT studies revealed that peripherally expanded, phenotypically memory T cells 1 to 3 months after transplant originated largely from naïve-derived rather than memory-derived T cells surviving PTCy, suggesting that initial resistance and subsequent immune reconstitution are distinct. These studies provide insight into the complex immune mechanisms active in CD8⁺ T-cell survival, differentiation, and reconstitution after cyclophosphamide, with relevance for post-HCT immune recovery, chemotherapy use in autologous settings, and adoptive cellular therapies.

Cyclophosphamide treatment in active multiple sclerosis

OBJECTIVE

Cyclophosphamide (CYC) is an alkylating agent with immunosuppressive effect by inhibiting DNA synthesis and producing apoptosis used in many autoimmune diseases, including multiple sclerosis (MS). Here, we analyze the efficacy of CYC treatment in relapsing-remitting (RRMS) and active secondary progressive MS (SPMS) in our center with a monthly scheme.

METHODS

Patients with MS treated with CYC and a follow up of at least 36 months were eligible for inclusion. All participants had received a standard CYC regimen. The EDSS score mean annualized relapse rate (ARR) and progression index (PI) were measured as efficacy outcomes at 12, 24, and 36 months. Outcomes were also analyzed comparing disease course and activity.

RESULTS

A total of 16 patients were included (50% male, 18.75% RRMS and 81.25% SPMS). EDSS remained stable along the follow-up period, with 62.5% improving or maintaining the same EDSS score at 12 months. PI decreased 14% and 21% at 12 and 24-36 months of follow-up, respectively. ARR decreased 20% after 12 months, 19% after 24 months, and 30.23% after 36 months. Median differences in ARR were higher in patients with high relapse activity (0.60 vs 0.07, p = 0.001) and malignant course (0.60 vs 0.17, p = 0.027). PI also differed with higher mean differences in patients with high relapse activity (0.70 vs 0.03, p = 0.016) and malignant course (1.17 vs 0.03, p = 0.003).

CONCLUSIONS

CYC continues to be a valid therapeutic option, especially in regions with limited access to high-efficiency therapies particularly in patients with high relapsing activity and malignant course.

European Academy of Neurology/Peripheral Nerve Society guideline on diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy: Report of a joint Task Force-Second revision

OBJECTIVE

To revise the 2010 consensus guideline on chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

METHODS

Seventeen disease experts, a patient representative, and two Cochrane methodologists constructed 12 Population/Intervention/Comparison/Outcome (PICO) questions regarding diagnosis and treatment to guide the literature search. Data were extracted and summarized in GRADE summary of findings (for treatment PICOs) or evidence tables (for diagnostic PICOs).

RESULTS

Statements were prepared according to the GRADE Evidence-to-Decision frameworks. Typical CIDP and CIDP variants were distinguished. The previous term "atypical CIDP" was replaced by "CIDP variants" because these are well characterized entities (multifocal, focal, distal, motor, or sensory CIDP). The levels of diagnostic certainty were reduced from three (definite, probable, possible CIDP) to only two (CIDP and possible CIDP), because the diagnostic accuracy of criteria for probable and definite CIDP did not significantly differ. Good Practice Points were formulated for supportive criteria and investigations to be considered to diagnose CIDP. The principal treatment recommendations were: (a) intravenous immunoglobulin (IVIg) or corticosteroids are strongly recommended as initial treatment in typical CIDP and CIDP variants; (b) plasma exchange is strongly recommended if IVIg and corticosteroids are ineffective; (c) IVIg should be considered as first-line treatment in motor CIDP (Good Practice Point); (d) for maintenance treatment, IVIg, subcutaneous immunoglobulin or corticosteroids are recommended; (e) if the maintenance dose of any of these is high, consider either combination treatments or adding an immunosuppressant or immunomodulatory drug (Good Practice Point); and (f) if pain is present, consider drugs against neuropathic pain and multidisciplinary management (Good Practice Point).

European Academy of Neurology/Peripheral Nerve Society guideline on diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy: Report of a joint Task Force-Second revision

To revise the 2010 consensus guideline on chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Seventeen disease experts, a patient representative, and two Cochrane methodologists constructed 12 Population/Intervention/Comparison/Outcome (PICO) questions regarding diagnosis and treatment to guide the literature search. Data were extracted and summarized in GRADE summary of findings (for treatment PICOs) or evidence tables (for diagnostic PICOs). Statements were prepared according to the GRADE Evidence-to-Decision frameworks. Typical CIDP and CIDP variants were distinguished. The previous term "atypical CIDP" was replaced by "CIDP variants" because these are well characterized entities (multifocal, focal, distal, motor, or sensory CIDP). The levels of diagnostic certainty were reduced from three (definite, probable, possible CIDP) to only two (CIDP and possible CIDP), because the diagnostic accuracy of criteria for probable and definite CIDP did not significantly differ. Good Practice Points were formulated for supportive criteria and investigations to be considered to diagnose CIDP. The principal treatment recommendations were: (a) intravenous immunoglobulin (IVIg) or corticosteroids are strongly recommended as initial treatment in typical CIDP and CIDP variants; (b) plasma exchange is strongly recommended if IVIg and corticosteroids are ineffective; (c) IVIg should be considered as first-line treatment in motor CIDP (Good Practice Point); (d) for maintenance treatment, IVIg, subcutaneous immunoglobulin or corticosteroids are recommended; (e) if the maintenance dose of any of these is high, consider either combination treatments or adding an immunosuppressant or immunomodulatory drug (Good Practice Point); and (f) if pain is present, consider drugs against neuropathic pain and multidisciplinary management (Good Practice Point).

Rituximab in refractory chronic inflammatory demyelinating polyneuropathy

INTRODUCTION

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a disorder in which early effective treatment is important to minimize disability from axonal degeneration. It has been suggested that some patients with CIDP may benefit from rituximab therapy, but there is no definitive evidence for this.

METHODS

Baseline and post-rituximab-therapy neuromuscular Medical Research Council (MRC) sum scores, Inflammatory Neuropathy Cause and Treatment (INCAT) disability score, and functional status were assessed in 11 patients with refactory CIDP.

RESULTS

The MRC sum score, INCAT disability score, and functional status improved in all patients after rituximab therapy.

DISCUSSION

Our study provides evidence of the efficacy of rituximab therapy in at least some patients with CIDP. A placebo-controlled study to assess the effectiveness of rituximab therapy in CIDP with and without nodal antibodies is required to identify disease markers that predict responsiveness.

Progress in Hematopoietic Stem Cell Transplantation for CIDP

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a kind of autoimmune-mediated inflammation and demyelinating disease. The etiology is mainly related to autoimmune dysfunction. The conventional treatments of CIDP have relied on immunomodulation and inhibition therapies such as adrenal cortex hormone, intravenous immunoglobulin (IVIg) and plasma exchange. Hematopoietic stem cell transplantation (HSCT) is known as a novel therapy for autoimmune disorders, which provides the chance to cure CIDP. More than 70 patients with refractory CIDP have received HSCT. The clinical symptoms and electrophysiological examination results of most patients have been improved. However, the treatment still has risks. This review describes the pathogenesis of CIDP and the current conventional treatments, and highlights the application of HSCT in CIDP, including its efficacy and safety.

T-lymphocyte in ANCA-associated vasculitis: what do we know? A pathophysiological and therapeutic approach

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is an autoimmune condition that commonly causes kidney impairment and can be fatal. The key participation of B-lymphocytes as ANCA producers and neutrophils as target of these antibodies is widely described as the mechanism of endothelial damage in this disease. There has been a rising interest in the role of T-lymphocytes in AAV in recent years. Evidence is strong from animal models, and T-lymphocytes can be found infiltrating kidney tissue and other tissue sites in AAV patients. Furthermore, the different subsets of T-lymphocytes are also key players in the aberrant immune response observed in AAV. Polarization towards a predominant Th1 and Th17 response in the acute phase of the disease has been described, along with a decline in the number of T-regulatory lymphocytes, which, in turn, show functional impairment. Interactions between different T-cell subsets, and between T-cells and neutrophils and B-cells, also enhance the inflammatory response, constituting a complex network. Novel therapies targeting T-cell immunity are emerging in this scenario and may constitute an interesting alternative to conventional therapy in selected patients. This review aims to summarize the available evidence regarding T-cell imbalances and functional impairment, especially focusing on renal involvement of AAV.

Novel immunotherapeutic strategies in chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a chronic immune-mediated neuropathy: it is clinically heterogeneous (relapsing-remitting form, chronic progressive form, monophasic form or CIDP having a Guillain-Barré syndrome-like onset), but potentially treatable. Although its pathophysiology remains largely unknown, CIDP is considered an immune-mediated neuropathy. Therefore, many immunotherapies have been proposed in this peripheral nervous system disorder, the most known efficient treatments being intravenous immunoglobulin, corticosteroids and plasma exchange. However, these therapies remain unsatisfactory for many patients, so numerous other immunotherapeutic strategies have been evaluated, based on their immunosuppressant or immunomodulatory potency. We have performed a large review of the literature about treatment in CIDP, with a special emphasis on novel and alternative immunotherapeutic strategies.

High-dose cyclophosphamide for moderate to severe refractory multiple sclerosis: 2-year follow-up (investigational new drug No. 65863)

High-dose cyclophosphamide (HDC) is a chemotherapy treatment designed to eradicate autoreative B- and T-cells responsible for lymphocyte-mediated autoimmune illness while sparing the pluripotent blood stem cell of any ill effects. Multiple sclerosis (MS) is the most common inflammatory and demyelinating immune-mediated disorder of the central nervous system in young adults. Patients with moderate to severe, refractory MS, defined as an Expanded Disability Status Scale (EDSS) score of 3.5 or higher after two or more Food and Drug Administration-approved disease-modifying agents, received 200 mg/kg of cyclophosphamide over 4 days. For the next 2 years, quarterly EDSS score evaluations and biannual brain magnetic resonance imaging and neuro-ophthalmologic evaluations were obtained. Fifteen patients were evaluated for clinical response. During follow-up, one patient increased their baseline EDSS score by 1.0. EDSS score stability of decrease was realized in five of seven (71%) patients with relapsing-remitting MS and six of eight (75%) patients with secondary progressive MS. Four patients required additional immunomodulatory treatment after treatment. Treatment response was seen regardless of the baseline presence or absence of contrast lesion activity. HDC can effectively decrease symptoms, stop disease progression, and allow for disability regression in relapsing-remitting MS and secondary progressive MS patients. The most appropriate candidates for HDC, its duration of benefit, and the potential need for prophylactic preventative immune manipulation after HDC all require further investigation.

The modulation of PPARγ1 and PPARγ2 mRNA expression by ciglitazone in CD3/CD28-activated naïve and memory CD4+ T cells

Given their roles in immune regulation, the expression of the nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ) 1 and 2 isoforms was investigated in human naïve (CD45RA+) and memory (CD45RO+) CD4+ T cells. Stimulation of both types of cells via the CD3/CD28 pathway resulted in high expression of both PPARγ receptors as measured by real-time PCR. Treatment with the PPARγ agonist, ciglitazone, increased PPARγ1 expression but decreased PPARγ2 expression in stimulated naïve and memory cells. Furthermore, when present, the magnitude of both PPARγ receptors expression was lower in naïve cells, perhaps suggesting a lower regulatory control of these cells. Similar profiles of selected proinflammatory cytokines were expressed by the two cell types following stimulation. The induction of PPARγ1 and suppression of PPARγ2 expressions in naïve and memory CD4+ T cells in the presence of ciglitazone suggest that the PPARγ subtypes may have different roles in the regulation of T-cell function.

Standard and escalating treatment of chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired, immune-mediated polyradiculoneuritis that is progressive or relapsing over a period of at least 8 weeks. Although the exact pathogenesis is unclear, it is thought to be mediated by both cellular and humoral immune reactions directed against the peripheral nerve myelin or axon. CIDP also involves spinal nerve roots. Early medical treatment of CIDP is important to prevent axonal loss. Only three treatment regimens for CIDP have demonstrated benefit in randomized, controlled studies: corticosteroids, plasma exchange, and intravenous immunoglobulins (IVIg). Approximately 25% of patients respond inadequately to corticosteroids, plasma exchange or IVIg. Large placebo-controlled trials with alternative immunosuppressive compounds, e.g. mycophenolate mofetil, cyclosporine, cyclophosphamide, or monoclonal antibodies, are lacking.

Cyclophosphamide in multiple sclerosis: scientific rationale, history and novel treatment paradigms

For patients with relapsing-remitting multiple sclerosis (RRMS), there are currently six approved medications that have been shown to alter the natural course of the disease. The approved medications include three beta interferon formulations, glatiramer acetate, natalizumab and mitoxantrone. Treating aggressive forms of RRMS and progressive disease forms of MS still presents a great challenge to neurologists. Intense immunosuppression has long been thought to be the only feasible therapeutic option. In patients with progressive forms of MS, lymphoid tissues have been detected in the central nervous system (CNS) that may play a critical role in perpetuating local inflammation. Agents that are currently approved for patients with MS have no or very limited bioavailability in the brain and spinal cord. In contrast, cyclophosphamide (CYC), an alkylating agent, penetrates the blood-brain barrier and CNS parenchyma well. However, while CYC has been used in clinical trials and off-label in clinical practice in patients with MS for over three decades, data on its efficacy in very heterogeneous groups of study patients have been conflicting. New myeloablative treatment paradigms with CYC may provide a therapeutic option in patients that do not respond to other agents. In this article we review the scientific rationale that led to the initial clinical trials with CYC. We will also outline the safety, tolerability and efficacy of CYC and provide neurologists with guidelines for its use in patients with MS and other inflammatory disorders of the CNS, including neuromyelitis optica (NMO). Finally, an outlook into relatively novel treatment approaches is provided.

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.

Fludarabine modulates composition and function of the T cell pool in patients with chronic lymphocytic leukaemia

The combination of cytotoxic treatment with strategies for immune activation represents an attractive strategy for tumour therapy. Following reduction of high tumour burden by effective cytotoxic agents, two major immune-stimulating approaches are being pursued. First, innate immunity can be activated by monoclonal antibodies triggering antibody-dependent cellular cytotoxicity. Second, tumour-specific T cell responses can be generated by immunization of patients with peptides derived from tumour antigens and infused in soluble form or loaded onto dendritic cells. The choice of cytotoxic agents for such combinatory regimens is crucial since most substances such as fludarabine are considered immunosuppressive while others such as cyclophosphamide can have immunostimulatory activity. We tested in this study whether fludarabine and/or cyclophosphamide, which represent a very effective treatment regimen for chronic lymphocytic leukaemia, would interfere with a therapeutic strategy of T cell activation. Analysis of peripheral blood samples from patients prior and during fludarabine/cyclophosphamide therapy revealed rapid and sustained reduction of tumour cells but also of CD4(+) and CD8(+) T cells. This correlated with a significant cytotoxic activity of fludarabine/cyclophosphamide on T cells in vitro. Unexpectedly, T cells surviving fludarabine/cyclophosphamide treatment in vitro had a more mature phenotype, while fludarabine-treated T cells were significantly more responsive to mitogenic stimulation than their untreated counterparts and showed a shift towards T(H)1 cytokine secretion. In conclusion, fludarabine/cyclophosphamide therapy though inducing significant and relevant T cell depletion seems to generate a micromilieu suitable for subsequent T cell activation.

Treatment in inflammatory neuropathies

This review focuses on recent developments in the treatment of inflammatory neuropathies arising from immune dysregulation, rather than from infectious causes. The dysimmune inflammatory neuropathies are diseases of the peripheral nerves that have varying etiologies and may respond to immunomodulatory therapies. They are characterized by inflammatory changes in the nerve with associated destruction of myelin and axons. The underlying immune mechanisms are better understood in some of these conditions than others. Correct diagnosis and treatment is important to prevent clinical progression. Randomized controlled trials of some treatments in the more common inflammatory neuropathies have clarified their effectiveness; however, there are still groups of patients who are resistant to currently available treatments and for whom little effective treatment is available. Newer, targeted biologics and larger controlled trials of existing and novel therapies in these conditions offer promise of improved morbidity and mortality in this group of diseases.