High-dose cyclophosphamide in the treatment of multiple sclerosis

Effect of Hematopoietic Stem Cell Transplantation and Post-Transplantation Cyclophosphamide on the Microglia Phenotype in Rats with Experimental Allergic Encephalomyelitis

Microglia are the resident immune cells of the central nervous system, playing a role in the inflammatory process development and resolution, presenting two main phenotypes, pro-inflammatory M1, and anti-inflammatory M2. Therapies affecting the microglia phenotype may be beneficial in treating inflammatory neurodegenerative diseases. In our experiments, we used the animal multiple sclerosis model, experimental allergic encephalomyelitis (EAE). Rats were treated during the pre- or symptomatic phase of the disease with cyclophosphamide, followed by hematopoietic stem cell transplantation, and with/without post-transplantation cyclophosphamide. Our study aimed to analyze the microglia phenotype in animals subjected to this treatment. The number of M1 cells in the spinal cord, and inducible nitric oxide synthase (iNOS) levels in the brain were similar in all experimental groups. The differences were observed in M2 cells number and arginase 1 (Arg1) levels, which were decreased in EAE animals, and increased after treatment in the symptomatic phase of EAE, and in the pre-symptomatic phase, but only with post-transplantation cyclophosphamide. Analysis of gene expression in the brain showed decreased iNOS expression in EAE animals treated in the symptomatic phase of EAE and no differences in Arg1 expression. Results indicate that treatment applied to experimental animals influences the microglia phenotype, promoting differentiation towards M2 cells.

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.

Neurotherapeutic Strategies for Multiple Sclerosis

Multiple sclerosis (MS) is the most common disabling neurologic disease of young adults. There are now 16 US Food and Drug Administration (FDA)-approved disease-modifying therapies for MS as well as a cohort of other agents commonly used in practice when conventional therapies prove inadequate. This article discusses approved FDA therapies as well as commonly used practice-based therapies for MS, as well as those therapies that can be used in patients attempting to become pregnant, or in patients with an established pregnancy, who require concomitant treatment secondary to recalcitrant disease activity.

Progressive multiple sclerosis: from pathogenic mechanisms to treatment

During the past decades, better understanding of relapsing-remitting multiple sclerosis disease mechanisms have led to the development of several disease-modifying therapies, reducing relapse rates and severity, through immune system modulation or suppression. In contrast, current therapeutic options for progressive multiple sclerosis remain comparatively disappointing and challenging. One possible explanation is a lack of understanding of pathogenic mechanisms driving progressive multiple sclerosis. Furthermore, diagnosis is usually retrospective, based on history of gradual neurological worsening with or without occasional relapses, minor remissions or plateaus. In addition, imaging methods as well as biomarkers are not well established. Magnetic resonance imaging studies in progressive multiple sclerosis show decreased blood-brain barrier permeability, probably reflecting compartmentalization of inflammation behind a relatively intact blood-brain barrier. Interestingly, a spectrum of inflammatory cell types infiltrates the leptomeninges during subpial cortical demyelination. Indeed, recent magnetic resonance imaging studies show leptomeningeal contrast enhancement in subjects with progressive multiple sclerosis, possibly representing an in vivo marker of inflammation associated to subpial demyelination. Treatments for progressive disease depend on underlying mechanisms causing central nervous system damage. Immunity sheltered behind an intact blood-brain barrier, energy failure, and membrane channel dysfunction may be key processes in progressive disease. Interfering with these mechanisms may provide neuroprotection and prevent disability progression, while potentially restoring activity and conduction along damaged axons by repairing myelin. Although most previous clinical trials in progressive multiple sclerosis have yielded disappointing results, important lessons have been learnt, improving the design of novel ones. This review discusses mechanisms involved in progressive multiple sclerosis, correlations between histopathology and magnetic resonance imaging studies, along with possible new therapeutic approaches.

Aggressive multiple sclerosis: proposed definition and treatment algorithm

Multiple sclerosis (MS) is a CNS disorder characterized by inflammation, demyelination and neurodegeneration, and is the most common cause of acquired nontraumatic neurological disability in young adults. The course of the disease varies between individuals: some patients accumulate minimal disability over their lives, whereas others experience a rapidly disabling disease course. This latter subset of patients, whose MS is marked by the rampant progression of disability over a short time period, is often referred to as having 'aggressive' MS. Treatment of patients with aggressive MS is challenging, and optimal strategies have yet to be defined. It is important to identify patients who are at risk of aggressive MS as early as possible and implement an effective treatment strategy. Early intervention might protect patients from irreversible damage and disability, and prevent the development of a secondary progressive course, which thus far lacks effective therapy.

Latin American algorithm for treatment of relapsing-remitting multiple sclerosis using disease-modifying agents

OBJECTIVE

It is estimated that circa 50,000 individuals have relapsing-remitting multiple sclerosis in Latin America. European and North-American algorithms for the treatment of multiple sclerosis do not foresee our regional difficulties and the access of patients to treatment.

METHODS

The Latin American Multiple Sclerosis Forum is an independent and supra-institutional group of experts that has assessed the latest scientific evidence regarding efficacy and safety of disease-modifying treatments. Accesses to treatment and pharmacovigilance programs for each of the eight countries represented at the Forum were also analyzed.

RESULTS

A specific set of guidelines based upon evidence-based recommendations was designed for Latin America. Future perspectives of multiple sclerosis treatment were also discussed.

CONCLUSIONS

The present paper translated an effort from representatives of eight countries discussing a matter that cannot be adapted to our region directly from purely European and North-American guidelines for treatment.

Immune mediated diseases and immune modulation in the neurocritical care unit

This chapter will review the spectrum of immune-mediated diseases that affect the nervous system and may result in an admission to the neurological intensive care unit. Immunomodulatory strategies to treat acute exacerbations of neurological diseases caused by aberrant immune responses are discussed, but strategies for long-term immunosuppression are not presented. The recommendations for therapeutic intervention are based on a synthesis of the literature, and include recommendations by the Cochrane Collaborative, the American Academy of Neurology, and other key organizations. References from recent publications are provided for the disorders and therapies in which randomized clinical trials and large evidenced-based reviews do not exist. The chapter concludes with a brief review of the mechanisms of action, dosing, and side effects of commonly used immunosuppressive strategies in the neurocritical care unit.

Treatment of relapsing-remitting multiple sclerosis with high-dose cyclophosphamide induction followed by glatiramer acetate maintenance

BACKGROUND

Previous studies have described stabilization of aggressive multiple sclerosis (MS) with one-time induction therapy with high-dose cyclophosphamide (HiCy). The long-term benefit of this stabilization followed by conventional therapy has not been explored.

OBJECTIVE

The objective of this study was to evaluate the safety and clinical outcomes following treatment of relapsing-remitting MS with HiCy induction therapy followed by glatiramer acetate maintenance.

METHODS

A retrospective review of a closely followed population of thirty two MS patients treated with HiCy (200mg/kg intravenous infusion over 4 days) followed by maintenance with glatiramer acetate was performed.

RESULTS

Annualized relapse rate was reduced from 1.37 in the 2 years prior to treatment to 0.27 over a mean post-treatment follow-up period of 14 months (range 0.5-33.8). The projected probability of relapse-free survival at 2 years was 0.64 (95% CI 0.37-0.82). The projected probability of Expanded Disability Status Scale (EDSS) progression-free survival at 2 years was 0.77 (95% CI 0.43-0.92). The mean number of gadolinium-enhanced lesions was reduced from 0.86 (SD 1.6) at baseline to 0 at 12 months and 0.08 (SD 0.28) at 15-24 months. A total of 55% of patients had no evidence of disease activity in follow-up. Infectious complications occurred in 47% with no long-term morbidity and no deaths.

CONCLUSIONS

Induction therapy with HiCy followed by long-term maintenance with glatiramer acetate is well tolerated in patients with MS, and appears to be efficacious in reducing the risk of relapse, disability progression, and new MRI lesions.

Disease-modifying agents in multiple sclerosis

Since 1993, six disease-modifying therapies for multiple sclerosis (MS) have been proven to be of benefit in rigorous phase III clinical trials. Other agents are also available and are used to treat MS, but definitive data on their efficacy is lacking. Currently, disease-modifying therapy is used for relapsing forms of MS. This includes clinically isolated syndrome/first-attack high-risk patients, relapsing patients, secondary progressive patients who are still experiencing relapses, and progressive relapsing patients. The choice of agent depends upon drug factors (including affordability, availability, convenience, efficacy, and side effects), disease factors (including clinical and neuroimaging prognostic indicators), and patient factors (including comorbidities, lifestyle, and personal preference). This review will discuss the disease-modifying agents used currently in MS, as well as available alternative agents.

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.

Cyclophosphamide and cancer: golden anniversary

Cyclophosphamide remains one of the most successful and widely utilized antineoplastic drugs. Moreover, it is also a potent immunosuppressive agent and the most commonly used drug in blood and marrow transplantation (BMT). It was initially synthesized to selectively target cancer cells, although the hypothesized mechanism of tumor specificity (activation by cancer cell phosphamidases) transpired to be irrelevant to its activity. Nevertheless, cyclophosphamide's unique metabolism and inactivation by aldehyde dehydrogenase is responsible for its distinct cytotoxic properties. Differential cellular expression of aldehyde dehydrogenase has an effect on the anticancer therapeutic index and immunosuppressive properties of cyclophosphamide. This Review highlights the chemistry, pharmacology, clinical toxic effects and current clinical applications of cyclophosphamide in cancer and autoimmune disorders. We also discuss the development of high-dose cyclophosphamide for BMT and the treatment of autoimmune diseases.