Primary central nervous system lymphoma in a patient treated with natalizumab

Breast Carcinoma After Ocrelizumab Therapy in Multiple Sclerosis Patients: A Case Series and Literature Review

Ocrelizumab is a humanized CD20 monoclonal antibody which was approved for management of Relapsing Remitting Multiple Sclerosis (RRMS) and Primary Progressive Multiple Sclerosis (PPMS) in 2017. We present 2 patients, a 67-year-old woman with history of PPMS and a 42-year-old woman with RRMS, who were started on ocrelizumab and were diagnosed with invasive ductal cell breast carcinoma after 2 years of ocrelizumab infusion followed by discontinuation of the drug. Large trials conducted for ocrelizumab showed malignancies in a total of 4 cases with RRMS in OPERA 1 trial conducted over 2 years from 2011 to 2013 (breast cancer, renal cell carcinoma, and melanomas) and in 11 cases with PPMS seen in ORATORIO trial conducted in 2017. There are currently no other published case reports of breast cancer in setting of ocrelizumab use for MS outside of large trials on literature review.

Pharmacovigilance during treatment of multiple sclerosis: early recognition of CNS complications

An increasing number of highly effective disease-modifying therapies for people with multiple sclerosis (MS) have recently gained marketing approval. While the beneficial effects of these drugs in terms of clinical and imaging outcome measures is welcomed, these therapeutics are associated with substance-specific or group-specific adverse events that include severe and fatal complications. These adverse events comprise both infectious and non-infectious complications that can occur within, or outside of the central nervous system (CNS). Awareness and risk assessment strategies thus require interdisciplinary management, and robust clinical and paraclinical surveillance strategies. In this review, we discuss the current role of MRI in safety monitoring during pharmacovigilance of patients treated with (selective) immune suppressive therapies for MS. MRI, particularly brain MRI, has a pivotal role in the early diagnosis of CNS complications that potentially are severely debilitating and may even be lethal. Early recognition of such CNS complications may improve functional outcome and survival, and thus knowledge on MRI features of treatment-associated complications is of paramount importance to MS clinicians, but also of relevance to general neurologists and radiologists.

Management of primary central nervous system lymphoma

A rare tumor, primary central nervous system lymphoma can affect immunocompetent and immunocompromised patients. While sensitive to radiotherapy or chemotherapy crossing the blood-brain barrier, it often recurs. Modern treatment consists of high-dose methotrexate-based induction chemotherapy, often followed by consolidation with either radiotherapy or further chemotherapy. Neurotoxicity is however a concern with radiotherapy, especially for patients older than 60 years. The benefit of the addition of rituximab to chemotherapy is unclear. Targeted therapies and immunotherapy have been effective in some patients and are tested on a larger scale. Survival has improved in the last decade, but remains poor in older patients.

Natalizumab-Associated Primary Central Nervous System Lymphoma

OBJECTIVE

Natalizumab, a selective adhesion molecule inhibitor binding to an α-4 subunit of integrin, has emerged to be an effective immunomodulator, especially in the treatment of relapsing-remitting multiple sclerosis and Crohn disease. Recent reports documenting the development of primary central nervous system lymphoma (PCNSL) as a result of its administration have been concerning, and they trigger a debate about a possible causal association. In our report, we provide a comprehensive review of the literature on lymphoma development after natalizumab use, and we report an additional case of PCNSL development in a young woman who received natalizumab for her Crohn disease.

METHODS

A systematic (qualitative) review of literature on lymphoma development after natalizumab therapy was performed by use of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data on patient characteristics, indication for drug therapy, dosages, radiologic findings, potential risk factors for PCNSL, and tumor markers were synthesized. Additionally, we present the findings from the case of a young woman who received natalizumab therapy (4 doses, 300 mg each) for Crohn disease and in whom PCNSL developed.

RESULTS

Overall, 8 reports including our index case document lymphoma development after natalizumab use. Our case finding revisits the debate suggesting a remote possibility of association that warrants further evaluation and validation.

CONCLUSIONS

Evidence documenting a causal association of natalizumab and PCNSL is weak. Considering the potential benefits of using natalizumab for current indications, we recommend vigilant monitoring of patients receiving the drug for PCNSL outlook.

Glioblastoma in natalizumab-treated multiple sclerosis patients

We present two natalizumab‐treated multiple sclerosis patients who developed glioblastoma multiforme (GBM) with variable outcomes. One patient had an isocitrate dehydrogenase (IDH)‐wildtype GBM with aggressive behavior, who declined treatment and died 13 weeks after symptoms onset. The other patient underwent resection of an IDH‐mutant secondary GBM that arose from a previously diagnosed grade II astrocytoma. He is still alive 5 years after the diagnosis of GBM. JC virus was not detected in either case. Whether natalizumab played a role in the development of GBM in those patients deserves further investigation.

Natalizumab treatment of multiple sclerosis: new insights

Natalizumab is a monoclonal antibody directed against the α4 chain of the very late activating antigen 4 and α4β7 integrins, present on the leukocytes surface, used as monotherapy for the treatment of relapsing-remitting multiple sclerosis. It substantially reduces relapse rate and the accumulation of disability, but its use is associated with a very adverse event, that is the development of progressive multifocal leukoencephalopathy, a fatal demyelinating disease of the CNS, due to the lytic replication of the human polyomavirus JC. The main focus of the review is to describe the newest insights on natalizumab, its current use in the clinical practice, the natalizumab-treated patients' management and the risk stratification related to the progressive multifocal leukoencephalopathy development.

Neuroimaging of Natalizumab Complications in Multiple Sclerosis: PML and Other Associated Entities

Natalizumab (Tysabri) is a monoclonal antibody (α4 integrin antagonist) approved for treatment of multiple sclerosis, both for patients who fail therapy with other disease modifying agents and for patients with aggressive disease. Natalizumab is highly effective, resulting in significant decreases in rates of both relapse and disability accumulation, as well as marked decrease in MRI evidence of disease activity. As such, utilization of natalizumab is increasing, and the presentation of its associated complications is increasing accordingly. This review focuses on the clinical and neuroimaging features of the major complications associated with natalizumab therapy, focusing on the rare but devastating progressive multifocal leukoencephalopathy (PML). Associated entities including PML associated immune reconstitution inflammatory syndrome (PML-IRIS) and the emerging phenomenon of rebound of MS disease activity after natalizumab discontinuation are also discussed. Early recognition of neuroimaging features associated with these processes is critical in order to facilitate prompt diagnosis, treatment, and/or modification of therapies to improve patient outcomes.

Risk Mitigation Strategies for Adverse Reactions Associated with the Disease-Modifying Drugs in Multiple Sclerosis

Over the past several years, the number of disease-modifying therapies (DMTs) for the treatment of multiple sclerosis (MS) has doubled in number. The 13 approved agents have shown a wide range of efficacy and safety in their clinical trials and post-marketing experience. While the availability of the newer agents allows for a wider selection of therapy for clinicians and patients, there is a need for careful understanding of the benefits and risks of each agent. Several factors such as the medication efficacy, side-effect profile, patient's preference, and co-morbidities need to be considered. An individualized treatment approach is thus imperative. In this review, risk stratification and mitigation strategies of the various disease-modifying agents are discussed.

Non-Hodgkin Lymphoma of the Stomach in a Patient Treated with Natalizumab

A 61-year-old man with relapsing-remitting multiple sclerosis developed extranodal large B-cell lymphoma of the stomach following monthly natalizumab infusions for 6 years. Development of lymphoproliferative disorders increases with chronic use of immunosuppression. Cases of primary central nervous system lymphoma as well as one case of peripheral T-cell lymphoma have previously been reported with natalizumab use. Given the absence of a known association between multiple sclerosis and extranodal presentations of diffuse large B-cell lymphoma, a causal association with natalizumab administration cannot be excluded.

Does a personal or family history of malignancy preclude the use of immunomodulators and biologics in IBD

The medical treatment for inflammatory bowel disease (IBD) has improved over the past 20 years. Although the routine use of immunomodulators and biologic agents in the treatment of IBD in the modern era has been a great achievement, these medicines are associated with rare but serious adverse events. In addition to the infectious complications, there are data to suggest that some of these agents are associated with higher rates of malignancy. In a patient with a history of cancer, or a family history of cancer, the gastroenterologist must be prepared to answer questions about the oncogenic potential of these agents. Thiopurines have been associated with a small increased risk of lymphoma in patients with IBD. In addition, an association with skin cancer has been established. Methotrexate is generally considered safe in patients with a history of cancer. There may be a small risk of lymphoma and possibly skin cancer with anti-tumor necrosis factor agents, but determining the cancer risk of these medications is difficult as they are often used in combination with thiopurines. In general, a family history of cancer should not influence a patient's medical regimen. Treatment for a patient with a personal history of cancer must be individualized and take into account the type and stage of cancer, time since completion of therapy, and the opinion of an oncologist.

The risk of malignancy associated with the use of biological agents in patients with inflammatory bowel disease

In this review, the available data regarding the risk of lymphoma, skin cancers, and other malignancies associated with biological agents that are approved and those under investigation for use in inflammatory bowel disease (IBD) are highlighted. How providers may approach the use of these agents in various clinical scenarios is discussed. This review may help providers better understand the true risk of malignancy associated with these agents, thereby leading to an enhanced communication process with patients with IBD when therapeutic decisions are being made.

Long-term safety and efficacy of natalizumab in relapsing-remitting multiple sclerosis: impact on quality of life

Natalizumab was the first monoclonal antibody to be approved for the treatment of relapsing-remitting multiple sclerosis (RRMS) based on its short-term efficacy and overall tolerability. However, the incidence of treatment-associated progressive multifocal leukoencephalopathy (PML), an infection of the brain caused by the John Cunningham virus, jeopardized this efficacious treatment from the beginning. Eight years after licensing of natalizumab, long-term studies confirm the considerable and sustained efficacy of natalizumab, although the PML complication still threatens one of the most successful treatments available for RRMS. During these years, considerable progress has been made in identification of risk factors that allow more effective management of PML risk. In addition, long-term studies to define better when to start or stop treatment and to optimize treatment strategies after cessation of natalizumab are ongoing, and hopefully will improve management and will allow natalizumab to remain as a valuable therapeutic option for patients with highly active RRMS.

Treatment options for patients with multiple sclerosis who have a suboptimal response to interferon-β therapy

BACKGROUND AND PURPOSE

Although the first-line disease-modifying therapies (DMTs) interferon beta and glatiramer acetate have a favourable benefit-to-risk profile, they are only partially effective for treating relapsing-remitting multiple sclerosis (RRMS). The optimization of treatment in patients who do not show a maximum response to first-line therapy is critical for achieving the best long-term outcomes. Treatment strategies for patients with a suboptimal response include switching to another first-line DMT or a second-line DMT. Natalizumab and fingolimod are approved for RRMS with high disease activity in the European Union and Canada.

METHODS

A comprehensive literature search for articles published between 1990 and April 2012 was undertaken.

RESULTS

This review discusses key clinical and safety data for fingolimod and natalizumab, particularly in the patient subgroups for whom these treatments are approved. Benefit-to-risk profiles, including first-dose cardiovascular effects associated with fingolimod and the risk of progressive multifocal encephalopathy with natalizumab, are discussed.

CONCLUSION

A descriptive comparison of fingolimod and natalizumab is provided in the context of the decision-making process of how and when to switch patients who have a suboptimal response to first-line therapy.

Bridging, switching or drug holidays - how to treat a patient who stops natalizumab?

Natalizumab (NAT) was the first monoclonal antibody to be approved for the treatment of relapsing-remitting multiple sclerosis (RRMS). While pivotal and postmarketing studies have showed considerable and sustained efficacy of NAT in RRMS, the increasing incidence of therapy-associated progressive multifocal leukoencephalopathy (PML), a brain infection caused by the John Cunningham virus (JCV), is a risk associated with long-term therapy. The risk for therapy-associated PML is highest in so-called “triple risk” patients. Therefore, long-term NAT-treated, immunosuppressive-pretreated, and JCV antibody-positive patients often discontinue NAT therapy. However, until now, it is not known which treatment strategy should be followed after NAT cessation. Since disease activity returns to pretreatment levels, or even above, within 4–7 months from the last infusion of NAT, patients who stop NAT are at considerable risk of relapse and worsening of multiple sclerosis (MS)-related disability. Several strategies have been applied to prevent the recurrence of disease activity after discontinuation of NAT. Of these, bridging with intravenous methylprednisolone, and switching to glatiramer acetate or interferon beta (IFN-beta) do not seem to be effective enough. More promising results have been obtained in retrospective studies and case series with fingolimod (FTY), an alternative escalation therapy for RRMS, although some patients have showed a severe disease rebound after starting FTY treatment. The time interval between the discontinuation of NAT and the start of FTY might affect the recurrence of disease activity. Long-term data about the efficacy and safety of FTY treatment after cessation of NAT are urgently needed and should be further investigated. Prospective studies are warranted, to optimize treatment strategies for RRMS patients who discontinue NAT, especially because new therapies will be available in the very near future.

Natalizumab therapy for multiple sclerosis

The treatment of relapsing remitting multiple sclerosis has witnessed major progress since the first effective disease modifying treatment, ß-interferon, became available in 1993. One of the most remarkable new treatments has been natalizumab. This review describes the evolution of this humanized anti-α4ß1 monoclonal antibody, from preclinical experimental research through proof-of-concept (phase 1/2) and pivotal (phase 3) clinical trials to the now extensive experience of its use in clinical practice. The future potential and challenges of natalizumab and oral therapies with a similar mechanism of action are also discussed.

Disease-specific therapy of idiopathic inflammatory demyelinating disorders

Central nervous system idiopathic inflammatory demyelinating disorders are a heterogenous group of diseases that share inflammation and demyelination as key features. Although the exact pathophysiology remains to be fully unveiled, these conditions are challenging to clinicians who seek specific therapeutic options for their patients. For two of these conditions, multiple sclerosis and neuromyelitis optica, there are now several possible therapies in an ever-evolving field. This review will touch on the various idiopathic inflammatory demyelinating disorders and discuss the various treatment options currently available.

Treating multiple sclerosis with natalizumab

Natalizumab is the first monoclonal antibody approved for the treatment of relapsing multiple sclerosis. Pivotal trials demonstrated the efficacy of natalizumab on clinical and paraclinical measures of disease activity and disability progression. Although a direct comparison has not been performed yet, natalizumab seems to be more efficacious than the currently available immunomodulant drugs, such as IFN-β and glatiramer acetate. Despite its efficacy, the occurrence of an increased risk of progressive multifocal leukoencephalopathy with the treatment, raises concerns about its widespread use in multiple sclerosis patients. This paper provides an overview of the most relevant results from the Phase I-IV studies on natalizumab and highlights the challenges addressed to minimize and manage its adverse events in clinical practice.

Clinical utility of glatiramer acetate in the management of relapse frequency in multiple sclerosis

Glatiramer acetate (GA) represents one of the most common disease-modifying therapies for multiple sclerosis. GA is currently approved for patients at high risk of developing clinically definite multiple sclerosis (CDMS) after having experienced a well-defined first clinical episode (clinically isolated syndrome or CIS) and for patients with relapsing-remitting multiple sclerosis (RRMS). GA’s efficacy and effectiveness to reduce relapse frequency have been proved in placebo-controlled and observational studies. Comparative trials have also confirmed the lack of significant differences over other choices of treatment in the management of relapse frequency, and long-term studies have supported its effect at extended periods of time. Additionally, RRMS patients with suboptimal response to interferon β may benefit from reduced relapse rate after switching to GA, and those with clinically isolated syndrome may benefit from delayed conversion to CDMS. All these results, together with its proven long-term safety and positive effect on patients’ daily living, support the favorable risk-benefit of GA for multiple sclerosis treatment.

Antigen-specific blocking of CD4-specific immunological synapse formation using BPI and current therapies for autoimmune diseases

In this review, we discuss T-cell activation, etiology, and the current therapies of autoimmune diseases (i.e., MS, T1D, and RA). T-cells are activated upon interaction with antigen-presenting cells (APC) followed by a "bull's eye"-like formation of the immunological synapse (IS) at the T-cell-APC interface. Although the various disease-modifying therapies developed so far have been shown to modulate the IS and thus help in the management of these diseases, they are also known to present some undesirable side effects. In this study, we describe a novel and selective way to suppress autoimmunity by using a bifunctional peptide inhibitor (BPI). BPI uses an intercellular adhesion molecule-1 (ICAM-1)-binding peptide to target antigenic peptides (e.g., proteolipid peptide, glutamic acid decarboxylase, and type II collagen) to the APC and therefore modulate the immune response. The central hypothesis is that BPI blocks the IS formation by simultaneously binding to major histocompatibility complex-II and ICAM-1 on the APC and selectively alters the activation of T cells from T(H)1 to T(reg) and/or T(H)2 phenotypes, leading to tolerance.

Complications of immunosuppressive/immunomodulatory therapy in neurological diseases

OPINION STATEMENT

The first critical step in the appropriate treatment of neurological infectious disease accompanying immunosuppressive states or immunomodulatory medication is to properly identify the offending organism. Broadly immunosuppressive conditions will predispose to both common and uncommon infectious diseases. There are substantial differences between neurological infectious disorders complicating disturbances of the innate immunity (neutrophils, monocytes and macrophages) and those due to abnormal adaptive immunity (humoral and cellular immunity). Similarly, there are differences in the types of infections with impaired humoral immunity compared to disturbed cellular immunity and between T- and B-cell disorders. HIV/AIDS has been a model of acquired immunosuppression and the nature of opportunistic infections with which it has been associated has been well characterized and generally correlates well with the degree of CD4 lymphopenia. Increasingly, immunotherapies target specific components of the immune system, such as an adhesion molecule or its ligand or surface receptors on a special class of cells. These targeted perturbations of the immune system increase the risk of particular infectious diseases. For instance, natalizumab, an α4β1 integrin inhibitor that is highly effective in multiple sclerosis, increases the risk of progressive multifocal leukoencephalopathy for reasons that still remain unclear. It is likely that other therapies that result in a disruption of a specific component of the immune system will be associated with other unique opportunistic infections. The risk of multiple simultaneous neurological infections in the immunosuppressed host must always be considered, particularly with a failure to respond to a therapeutic regimen. With respect to appropriate and effective therapy, diagnostic accuracy assumes primacy, but occasionally broad spectrum therapy is necessitated. For a number of opportunistic infectious disorders, particularly some viral and fungal diseases, antimicrobial therapy remains inadequate.

New and Emerging Disease-Modifying Therapies for Relapsing-Remitting Multiple Sclerosis: What is New and What is to Come

The therapeutic landscape for multiple sclerosis (MS) is rapidly changing. Currently, there are eight FDA approved disease modifying therapies for MS including: IFN-β-1a (Avonex, Rebif), IFN-β-1b (Betaseron, Extavia), glatiramer acetate (Copaxone), mitoxantrone (Novantrone), natalizumab (Tysabri), and fingolimod (Gilenya). This review will highlight the experience to date and key clinical trials of the newest FDA approved agents, natalizumab and fingolimod. It will also review available efficacy and safety data on several promising therapies under active investigation including four monoclonal antibody therapies: alemtuzumab, daclizumab, ocrelizumab and ofatumumab and three oral agents: BG12, laquinimod, and teriflunomide. To conclude, we will discuss where each of these new therapies may best fit into treatment algorithms.

Cell Trafficking in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is an indolent lymphoproliferative disorder characterized by both circulating peripheral disease as well as involvement of the lymph nodes and bone marrow. Increasing evidence suggests that the stromal microenvironment provides anti-apoptotic and pro-survival signals to CLL cells, and may contribute significantly to resistance to a wide variety of treatments. Our understanding of the complex interactions involved in CLL cell trafficking continues to grow. Chemokines and corresponding chemokine receptors are key factors for organizing CLL cell trafficking and homing and the complex cellular interactions between CLL and accessory cells. Important chemokines include CCL3, CCL4, and CCL22, which are released by CLL cells, and CXCL12, CXCL13, CXCL9, 10, 11, CCL 19, and CCL21, which are constitutively secreted by various stromal cells. Integrins such as VLA-4 (CD49d) as well as selectins and CD44 also likely play a role in directing CLL cell migration within the tissue microenvironments. Data are also emerging that other molecules such as MMP-9 and cytoskeletal proteins also contribute to CLL cell trafficking. Though this interplay is complex, it is critical that we improve our understanding of CLL cell trafficking to facilitate the development of novel therapies that target these pathways. Several drugs in clinical development, such as CXCR4 antagonists and PI3K, Btk, and Syk inhibitors appear to modulate CLL cell trafficking and CLL-stroma interactions. Here, we review the current understanding of the molecular interactions that underlie CLL cell trafficking and we highlight some of the promising approaches underway to target these pathways therapeutically in CLL.

Monoclonal antibodies and recombinant immunoglobulins for the treatment of multiple sclerosis

Multiple sclerosis (MS) is an inflammatory and degenerative disease leading to demyelination and axonal damage in the CNS. Autoimmunity plays a central role in MS pathogenesis. Per definition, monoclonal antibodies are recombinant biological compounds with a well defined target, thus carrying the promise of targeting pathogenic cells or molecules with high specificity, avoiding undesired off-target effects. Natalizumab was the first monoclonal antibody to be approved for the treatment of MS. Several other monoclonal antibodies are in development and have demonstrated promising efficacy in phase II studies. They can be categorized according to their mode of action into compounds targeting (i) leukocyte migration into the CNS (natalizumab); (ii) cytolytic antibodies (rituximab, ocrelizumab, ofatumumab, alemtuzumab); or (iii) antibodies and recombinant proteins targeting cytokines and chemokines and their receptors (daclizumab, ustekinumab, atacicept, tabalumab [Ly-2127399], secukinumab [AIN457]). In this review, we discuss the specific molecular targets, clinical efficacy and safety of these compounds and discuss criteria to anticipate the position of monoclonal antibodies in the diversifying armamentarium of MS therapy in the coming years.

Natalizumab for relapsing remitting multiple sclerosis

BACKGROUND

Natalizumab (NTZ) (Tysabri(®)) is a monoclonal antibody that inhibits leukocyte migration across the blood-brain barrier, thus reducing inflammation in central nervous system, and has been approved worldwide for the treatment of relapsing-remitting multiple sclerosis (RRMS).

OBJECTIVES

To evaluate the efficacy, tolerability and safety of NTZ in the treatment of patients with RRMS.

SEARCH STRATEGY

We searched the Cochrane Multiple Sclerosis Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, 2010, Issue 1), MEDLINE (PubMed) and EMBASE, all up to 19 February 2010, and bibliographies of papers. Handsearching was carried out. Trialists and pharmaceutical companies were contacted. Furthermore, the websites of US Food and Drug Administration (FDA), the European Medicines Evaluation Agency (EMA) and the National Institute for health and Clinical Excellence (NICE) were also checked.

SELECTION CRITERIA

All double-blind, randomised, controlled trials analysing more than a single infusion of NTZ (dosage > 3 mg/kg intravenous infusion every 4 weeks), also including its use as add-on treatment, versus placebo or other drugs in patients with RRMS. No restrictions on the basis of duration of treatment or length of follow up.

DATA COLLECTION AND ANALYSIS

Three reviewers independently selected articles which met the inclusion criteria. Disagreements were solved by discussion. Two reviewers independently extracted the data and assessed the methodological quality of each trial. Missing data was sought by contacting principal authors and Biogen Idec, through Biogen-Dompé Italia.

MAIN RESULTS

Three studies met the inclusion criteria. These included one placebo-controlled trial (942 patients) and two add-on placebo-controlled trials, i.e. one plus glatiramer acetate (110 patients) and the second plus interferon beta-1a (1171 patients).This review assessed the efficacy, tolerability and safety of NTZ in patients with RRMS. Data was conclusive with respect to efficacy and tolerability, but not safety. As far as efficacy is concerned, the results showed statistically significant evidence in favour of NTZ for all the primary outcomes and for the secondary ones where data was available. NTZ reduced the risk of experiencing at least one new exacerbation at 2 years by about 40% and of experiencing progression at 2 years by about 25% as compared to a control group. MRI parameters showed statistical evidence in favour of participants receiving NTZ. Infusion reactions, anxiety, sinus congestion, lower limb swelling, rigors, vaginitis and menstrual disorders were reported as adverse events (AEs) more frequently after NTZ treatment. In this review NTZ was found to be well tolerated over a follow-up period of two years: the number of patients experiencing at least one AE (including severe and serious AEs) during this period did not differ between NTZ-treated patients and controls. Safety concerns have been raised about Progressive Multifocal Leukoencephalopathy (PML). In the trials included in this review, two cases of PML were encountered: one in a patient who had received 29 doses of NTZ and a second fatal case of PML in another patient after 37 doses of NTZ. Our protocol was insufficient to evaluate PML risk as well as other rare and long-term adverse events such as cancers and other opportunistic infections, which are very important issues in considering the risk/benefit ratio of NTZ.

AUTHORS' CONCLUSIONS

Although one trial did not contribute to efficacy results due to its duration, we found robust evidence in favour of a reduction in relapses and disability at 2 years in RRMS patients treated with NTZ. The drug was well tolerated. There are current significant safety concerns due to reporting of an increasing number of PML cases in patients treated with NTZ. This review was unable to provide an up-to-date systematic assessment of the risk due to the maximum 2 year-duration of the trials included. An independent systematic review of the safety profile of NTZ is warranted. NTZ should be used only by skilled neurologists in MS centres under surveillance programs.All the data in this review came from trials supported by the Pharmaceutical Industry. In agreement with the Cochrane Collaboration policy, this may be considered a potential source of bias.

Natalizumab treatment for multiple sclerosis: updated recommendations for patient selection and monitoring

Natalizumab, a highly specific α4-integrin antagonist, is approved for treatment of patients with active relapsing-remitting multiple sclerosis (RRMS). It is generally recommended for individuals who have not responded to a currently available first-line disease-modifying therapy or who have very active disease. The expected benefits of natalizumab treatment have to be weighed against risks, especially the rare but serious adverse event of progressive multifocal leukoencephalopathy. In this Review, we revisit and update previous recommendations on natalizumab for treatment of patients with RRMS, based on additional long-term follow-up of clinical studies and post-marketing observations, including appropriate patient selection and management recommendations.

Toxicities of immunosuppressive treatment of autoimmune neurologic diseases

In parallel to our better understanding of the role of the immune system in neurologic diseases, there has been an increased availability in therapeutic options for autoimmune neurologic diseases such as multiple sclerosis, myasthenia gravis, polyneuropathies, central nervous system vasculitides and neurosarcoidosis. In many cases, the purported benefits of this class of therapy are anecdotal and not the result of good controlled clinical trials. Nonetheless, their potential efficacy is better known than their adverse event profile. A rationale therapeutic decision by the clinician will depend on a comprehensive understanding of the ratio between efficacy and toxicity. In this review, we outline the most commonly used immune suppressive medications in neurologic disease: cytotoxic chemotherapy, nucleoside analogues, calcineurin inhibitors, monoclonal antibodies and miscellaneous immune suppressants. A discussion of their mechanisms of action and related toxicity is highlighted, with the goal that the reader will be able to recognize the most commonly associated toxicities and identify strategies to prevent and manage problems that are expected to arise with their use.

Modern concepts in the biology, diagnosis, differential diagnosis and treatment of primary central nervous system lymphoma

Recent studies addressing the molecular characteristics of PCNSL, which is defined as malignant B-cell lymphoma with morphological features of DLBCL, have significantly improved our understanding of the pathogenesis of this lymphoma entity, which is associated with an inferior prognosis as compared with DLBCL outside the CNS. This unfavorable prognosis stimulated intense efforts to improve therapy and induced recent series of clinical studies, which addressed the role of radiotherapy and various chemotherapeutic regimens. This review combines the discussion of diagnosis, differential diagnosis and recent progress in studies addressing the molecular pathogenesis as well as therapeutic options in PCNSL.

Natalizumab in pediatric multiple sclerosis patients

Pediatric multiple sclerosis (MS) comprises 2-5% of all cases of MS. Although first-line disease-modifying therapy (DMT) including interferons and glatiramer acetate appear to be well tolerated in this population, recent work has suggested that a growing number of children suffer from disease which is resistant to treatment with these therapies. Natalizumab is a therapy which, although associated with a 1 : 1000 risk for progressive multifocal leukoencephalopathy (PML), has been shown to be well tolerated in the adult population and may lead to disease remission in adults with highly active disease. Reports of use of this therapy in the pediatric population with highly active disease have been published. This paper reviews current experience with the use of natalizumab in the pediatric MS population, with attention to potential risks and possible long-term outcomes in this population.

Monoclonal antibody therapy in multiple sclerosis: Paradigm shifts and emerging challenges

Therapeutic approaches to multiple sclerosis (MS) are based on altering the functions of the immune system, either by using broad immunosuppressive drugs used for transplantation rejection and rheumatology, or by modulating them more discreetly with beta interferon and synthetic amino-acid copolymers. These strategies are only partially successful, have important safety and tolerability limitations, and have shown to be mostly effective in earlier stages of the disease, in which acute relapses dominate the clinical picture. For progressive phenotypes of MS there are currently no effective therapeutic options. As very specific and potent immunosuppressive agents, monoclonal antibodies (mAbs) may offer considerable advantages over other therapies for MS. During the last decade, anti-a4 integrin natalizumab became the first approved mAb for treatment of relapsing MS, after convincingly demonstrating clinically significant effects on two large Phase 3 trials. Moreover, the concept of disease remission was introduced for the first time, to describe patients that show no signs of clinical or imaging markers of disease activity during therapy with natalizumab. Of the mAbs under development for MS, alemtuzumab and rituximab have also shown promising evidence of effectiveness, and potentially expanded the therapeutic horizon to reversal of disease progression in early relapsing patients, and progressive patients who previously had not been studied. However, the appearance of progressive multifocal leukoencephalopathy (PML) in natalizumab-treated MS patients, as well as in patients with lymphoma, lupus and rheumatoid arthritis treated with rituximab, and autoimmune-type complications in alemtuzumab-treated MS patients underlines the fact that extended efficacy comes with significant clinical risks. The challenge is then how best to utilize therapies that have evidently superior efficacy in a chronic disease of young adults, to obtain the best benefit-risk ratio, and how to monitor and prevent emergent safety concerns.

Update on the risk of lymphoma following immunosuppressive therapy for inflammatory bowel disease

The care of inflammatory bowel disease has changed considerably with the introduction of a number of immunosuppressants including anti-metabolite and anti-TNF therapies. While efficacious, these medications also carry important risks, notably the potential risk of lymphoma. This risk is one of the most worrisome for both patients and physicians. Our current knowledge is still evolving; however, our understanding of what risks these drugs carry, both individually and synergistically, is critical in allowing informed decision making. In this article, we will describe the known lymphoma risks of commonly used immunosuppressant medications in inflammatory bowel disease, with an emphasis on non-Hodgkin's lymphoma and hepatosplenic T-cell lymphoma.

[Therapeutic monoclonal antibodies in clinical neurology]

Recombinant monoclonal antibodies break new ground in the treatment of immune-mediated nerve and muscle disorders but also of neurodegenerative diseases, in the field of neuro-oncology and in pain therapy, as they allow molecular targeting of defined cell populations or key pathophysiological molecules. However, safety risks might accompany a high efficacy. Basic understanding of this increasingly important class of agents and a steady update of knowledge, in particular on safety aspects, are therefore key requirements for responsible use based on an individual benefit-risk assessment.

Treating multiple sclerosis with monoclonal antibodies: a 2010 update

Treating multiple sclerosis (MS) with monoclonal antibodies (mAbs) has been marked by both progress and setbacks in the past 2 years, which are reviewed here. The natalizumab section of the article centers around progressive multifocal leukoencephalopathy (PML), and discusses PML risk in relation to treatment duration, bioassays for individual risk prediction, the concept of drug holidays, clinical course and treatment of PML, as well as safety-related regulatory actions. The rituximab section critically analyzes recent clinical trial results, discusses the clinical relevance of anti-idiotypic mAbs and makes a short excursion to neuromyelitis optica. Following this, the newer anti-CD20 mAbs ocrelizumab and ofatumumab, which are currently being tested in Phase II for MS, are reviewed and compared. The alemtuzumab section highlights novel data on mechanisms of action, potentially allowing individual risk prediction, and new results from the CAMMS223 trial, as well as the current status of the pivotal MS studies. The daclizumab section summarizes new open-label data, shedding more light on the adverse-effect profile of the drug in MS patients, and reports on its Phase III status. Subsequently, a failed ustekinumab trial and LY2127399 are reviewed. Taking into account late Phase II and III data on novel oral agents, the final section attempts to provide a detailed perspective on disease-modifying MS therapy in the medium term.

Demyelination as a complication of new immunomodulatory treatments

PURPOSE OF REVIEW

This review discusses demyelinating events of the nervous system that have been associated with new immunomodulatory treatments, in particular monoclonal antibodies (mAbs).

RECENT FINDINGS

Natalizumab, a mAb targeting the alpha-4 integrins, which is efficient in relapsing-remitting multiple sclerosis, has been associated with progressive multifocal leukoencephalopathy (PML). We will review the putative mechanisms linking natalizumab with JC virus, the agent of PML. Efalizumab, a mAb targeting a member of the integrin family, CD11a, was approved for the treatment of psoriasis, but had to be withdrawn in 2009 because of the occurrence of three cases of PML. Rituximab, an anti-CD20 mAb, is used in different neoplastic and autoimmune diseases and may soon enter the pharmacopeia of multiple sclerosis. It has been suggested that rituximab is a risk factor for PML; however, evidence of such a link is unclear. Antitumor necrosis factor-alpha agents are used in several autoimmune diseases. Several cases of demyelinating events of the nervous system have been reported, prompting a heightened surveillance of treated patients. Recent data are reassuring, suggesting that the incidence of such events is relatively low.

SUMMARY

Neurologists must become familiar with neurological complications of new immunomodulatory treatments, a field situated at the interface of neurology, immunology and infection.

Hydrocephalus during natalizumab treatment

Natalizumab is a humanized monoclonal antibody recently approved for multiple sclerosis treatment. Although generally well tolerated and efficacious in multiple sclerosis treatment, it raised concerns after the occurrence of some cases of progressive multifocal leucoencephalopathy in exposed patients. Extensive and prolonged use of natalizumab could unmask further unexpected side effects. We describe the case of a woman suffering from multiple sclerosis who experienced an acute tetra-ventricular hydrocephalus soon after the beginning of immunomodulating treatment with natalizumab. The patient was also affected with a VIII cranial nerve Schwannoma treated with stereotactic radiosurgery 2 years before, with subsequent clinical and radiological stabilization. The strict temporal correlation between clinical worsening and natalizumab therapy points to a possible triggering role of the drug in the pathogenesis of hydrocephalus in our patient. Treating neurologists should be aware of this possible complication in selected subsets of patients.

Risks vs benefits of glatiramer acetate: a changing perspective as new therapies emerge for multiple sclerosis

An understanding of the risks, benefits, and relative value of glatiramer acetate (GA) in multiple sclerosis (MS) has been evolving based on recently completed head-to-head studies: REGARD (REbif vs Glatiramer Acetate in Relapsing MS Disease); BEYOND (Betaseron Efficacy Yielding Outcomes of a New Dose); and BECOME (BEtaseron vs COpaxone in Multiple Sclerosis with Triple-Dose Gadolinium and 3-Tesla MRI Endpoints). Outcomes in the primary endpoints of these trials showed no significant differences between GA and high-dose beta-interferons (IFNβs). Results of the PreCISe (Early GA Treatment in Delaying Conversion to Clinically Definite Multiple Sclerosis [CDMS] in Subjects Presenting With a Clinically Isolated Syndrome [CIS]) trial led to the US Food and Drug Administration approval of GA in patients with a CIS. Furthermore, the ongoing follow-up study to the original pivotal GA trial, now extending beyond 15 years, continues to support the safety of GA. Currently, GA and IFNβs are no longer the only immunomodulators available for MS. Introduction of the monoclonal antibody, natalizumab (Tysabri^®; Biogen Idec, Inc., Cambridge, MA, USA) provides an alternative immunomodulator for MS and has changed the therapeutic landscape dramatically. However, the rare but serious cases of progressive multifocal leukoencephalopathy that have occurred with natalizumab have raised concerns among clinicians and patients about using this agent and some of the emerging agents. The potential risks and benefits of the emerging therapies (cladribine, alemtuzumab, rituximab, fingolimod, laquinimod, teriflunomide, and dimethyl fumarate) based on phase II/III trials, as well as their use for indications other than MS, will be presented. This review provides available data on GA, natalizumab, and the emerging agents to support new developments in our understanding of GA and how its long-standing role as a first-line therapy in MS will evolve within the increasingly complex MS therapeutic landscape.