Expert opinion: guidelines for the use of natalizumab in multiple sclerosis patients previously treated with immunomodulating therapies

AXL+SIGLEC6+ dendritic cells in cerebrospinal fluid and brain tissues of patients with autoimmune inflammatory demyelinating disease of CNS

Inflammatory demyelinating disease of the CNS (IDD) is a heterogeneous group of autoimmune diseases, and multiple sclerosis is the most common type. Dendritic cells (DCs), major antigen-presenting cells, have been proposed to play a central role in the pathogenesis of IDD. The AXL+SIGLEC6+ DC (ASDC) has been only recently identified in humans and has a high capability of T cell activation. Nevertheless, its contribution to CNS autoimmunity remains still obscure. Here, we aimed to identify the ASDC in diverse sample types from IDD patients and experimental autoimmune encephalomyelitis (EAE). A detailed analysis of DC subpopulations using single-cell transcriptomics for the paired cerebrospinal fluid (CSF) and blood samples of IDD patients (total n = 9) revealed that three subtypes of DCs (ASDCs, ACY3+ DCs, and LAMP3+ DCs) were overrepresented in CSF compared with their paired blood. Among these DCs, ASDCs were also more abundant in CSF of IDD patients than in controls, manifesting poly-adhesional and stimulatory characteristics. In the brain biopsied tissues of IDD patients, obtained at the acute attack of disease, ASDC were also frequently found in close contact with T cells. Lastly, the frequency of ASDC was found to be temporally more abundant in acute attack of disease both in CSF samples of IDD patients and in tissues of EAE, an animal model for CNS autoimmunity. Our analysis suggests that the ASDC might be involved in the pathogenesis of CNS autoimmunity.

Role of chemokine systems in cancer and inflammatory diseases

Chemokines are a large family of small secreted proteins that have fundamental roles in organ development, normal physiology, and immune responses upon binding to their corresponding receptors. The primary functions of chemokines are to coordinate and recruit immune cells to and from tissues and to participate in regulating interactions between immune cells. In addition to the generally recognized antimicrobial immunity, the chemokine/chemokine receptor axis also exerts a tumorigenic function in many different cancer models and is involved in the formation of immunosuppressive and protective tumor microenvironment (TME), making them potential prognostic markers for various hematologic and solid tumors. In fact, apart from its vital role in tumors, almost all inflammatory diseases involve chemokines and their receptors in one way or another. Modulating the expression of chemokines and/or their corresponding receptors on tumor cells or immune cells provides the basis for the exploitation of new drugs for clinical evaluation in the treatment of related diseases. Here, we summarize recent advances of chemokine systems in protumor and antitumor immune responses and discuss the prevailing understanding of how the chemokine system operates in inflammatory diseases. In this review, we also emphatically highlight the complexity of the chemokine system and explore its potential to guide the treatment of cancer and inflammatory diseases.

Dendritic Cells and CCR7 Expression: An Important Factor for Autoimmune Diseases, Chronic Inflammation, and Cancer

Chemotactic cytokines-chemokines-control immune cell migration in the process of initiation and resolution of inflammatory conditions as part of the body's defense system. Many chemokines also participate in pathological processes leading up to and exacerbating the inflammatory state characterizing chronic inflammatory diseases. In this review, we discuss the role of dendritic cells (DCs) and the central chemokine receptor CCR7 in the initiation and sustainment of selected chronic inflammatory diseases: multiple sclerosis (MS), rheumatoid arthritis (RA), and psoriasis. We revisit the binary role that CCR7 plays in combatting and progressing cancer, and we discuss how CCR7 and DCs can be harnessed for the treatment of cancer. To provide the necessary background, we review the differential roles of the natural ligands of CCR7, CCL19, and CCL21 and how they direct the mobilization of activated DCs to lymphoid organs and control the formation of associated lymphoid tissues (ALTs). We provide an overview of DC subsets and, briefly, elaborate on the different T-cell effector types generated upon DC-T cell priming. In the conclusion, we promote CCR7 as a possible target of future drugs with an antagonistic effect to reduce inflammation in chronic inflammatory diseases and an agonistic effect for boosting the reactivation of the immune system against cancer in cell-based and/or immune checkpoint inhibitor (ICI)-based anti-cancer therapy.

Self-Limited Cytomegalovirus Infection During Natalizumab Treatment for Multiple Sclerosis

Natalizumab is indicated as monotherapy for the treatment of relapsing-remitting multiple sclerosis; it prevents outbreaks and delays the progression of physical disability. Here, we report the case of a 30-year-old patient with multiple sclerosis receiving natalizumab as monotherapy who subsequently developed self-limited cytomegalovirus disease. Cytomegalovirus infection has been reported during treatment with natalizumab, and in this study, we use new techniques to analyze the possible association of cytomegalovirus infection with natalizumab.

LEARNING POINTS

Natalizumab is a humanized recombinant monoclonal antibody (IgG4k) against α4-integrin which promotes immunocompromise by blocking the adhesion interactions necessary for lymphocyte trafficking.Cytomegalovirus infection has been described during natalizumab treatment, although the pathogenesis and mechanisms are not complete understood.This case highlights the importance of awareness of this association and possible complications.

Severe Cytomegalovirus Gastritis During Natalizumab-Mediated Immunosuppression

We report a 35-year-old female receiving natalizumab as monotherapy for multiple sclerosis who subsequently developed severe cytomegalovirus gastritis. As cytomegalovirus gastritis has not been previously described during natalizumab treatment, we discuss the biological plausibility of this potential association and avenues for further study.

Latent tuberculosis seems not to reactivate in multiple sclerosis patients on natalizumab

Current safety recommendations for multiple sclerosis (MS) patients who are considered for natalizumab do not specify how to screen for latent tuberculosis (LTB). Only chest X-ray is recommended as a routine, and follow-up depends on its results. The incidence of TB in Spain is high and the risk of a LTB reactivation due to natalizumab is unknown. Our objective is to describe in our clinical practice if following the current recommendations for the MS population on natalizumab allows identifying patients with a LTB, as well as the risk for TB reactivation. Our study demonstrated that, in our environment, current recommendations are not sensitive enough to identify cases of LTB, though no cases of active TB were observed. Considering the lack of documented active TB cases worldwide among natalizumab patients, we suggest that these safety measures are probably unnecessary, even in countries with a high TB incidence.

CD49d expression as a promising biomarker to monitor natalizumab efficacy

Natalizumab (Tysabri™), a monoclonal antibody against the α4-integrin of VLA-4 (CD49d) antigen of leukocytes, is highly effective in multiple sclerosis (MS). The most common reason for treatment failure is the development of neutralizing antibodies (NAbs). According to health authorities Nabs testing is recommended in case of relapse or repeated infusion reactions. However NAbs may develop in clinically asymptomatic patients. In this study we investigated if CD49d expression could serve as a biomarker of natalizumab bioavailability and treatment response. In a cohort of 49 natalizumab treated relapsing-remitting MS, followed over 2 years, CD49d expression was determined on peripheral blood mononuclear cells (PBMCs) before each infusion and compared to NAbs and serum natalizumab levels. In a majority of patients (41/49) the CD49d expression in PBMCs was strongly inhibited (>50%) after the first infusion and maintained at low levels throughout the treatment period. In contrast, in eight patients (16%) there was an early recovery of CD49d expression to pre-treatment levels related to NABs development. While three cases experienced hypersensitivity reactions, three others were identified solely on the basis of an undiminished level of CD49d, with neither infusion reaction nor clinical worsening. These 3 patients had very high levels of NAbs and no detectable serum natalizumab. Two additional patients had early but transient recovery of CD49d expression. These patients had low levels of transient Nabs and returned to significant CD49d inhibition after few natalizumab infusions. We suggest that monitoring of CD49d expression can be used as a surrogate biomarker of natalizumab efficiency. If the CD49d expression is sustained at pre-treatment levels, patients should be tested for persistent NAbs and considered for treatment interruption.

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.

Innovative monoclonal antibody therapies in multiple sclerosis

The recent years have witnessed great efforts in establishing new therapeutic options for multiple sclerosis (MS), especially for relapsing-remitting disease courses. In particular, the application of monoclonal antibodies provide innovative approaches allowing for blocking or depleting specific molecular targets, which are of interest in the pathogenesis of MS. While natalizumab received approval by the US Food and Drug Administration and the European Medicines Agency in 2006 as the first monoclonal antibody in MS therapy, rituximab, alemtuzumab, and daclizumab were successfully tested for relapsing-remitting MS in small cohorts in the meantime. Here, we review the data available from these recent phase II trials and at the same time critically discuss possible pitfalls which may be relevant for clinical practice. The results of these studies may not only broaden our therapeutic options in the near future, but also provide new insights into disease pathogenesis.

Natalizumab for the treatment of relapsing multiple sclerosis

Natalizumab is an α4-integrin antagonist approved as monotherapy for patients with relapsing multiple sclerosis (MS), based on demonstrated efficacy in the pivotal AFFIRM study (N = 942). Natalizumab monotherapy reduced risk of disability progression by 42%–54% and annualized relapse rate by 68% during a period of 2 years. Natalizumab was also associated with significant reductions in number of T2-hyperintense, gadolinium-enhancing, and T1-hypointense lesions and in volume of T2-hyperintense lesions (all p < 0.001) on magnetic resonance imaging. Furthermore, natalizumab-treated patients in AFFIRM experienced significant improvements from baseline in the physical and mental components of the Short Form-36 (p ≤ 0.01) and a 35% reduction in risk of clinically significant vision loss (p = 0.008 vs placebo). Natalizumab was well tolerated in phase 3 studies. Common adverse events were generally mild and included headache, fatigue, urinary tract infections, and arthralgia. Serious adverse events were similar between treatment groups. The incidence of serious hypersensitivity reactions associated with natalizumab was <1%. Progressive multifocal leukoencephalopathy was a rare complication of treatment, observed in 2 patients with MS who received natalizumab plus interferon β-1a. The robust clinical benefits of natalizumab, including benefits on patient-reported quality of life, make it an important addition to disease-modifying therapies available to patients with relapsing MS.

Functional energetics of CD4+-cellular immunity in monoclonal antibody-associated progressive multifocal leukoencephalopathy in autoimmune disorders

BACKGROUND

Progressive multifocal leukoencephalopathy (PML) is an opportunistic central nervous system- (CNS-) infection that typically occurs in a subset of immunocompromised individuals. An increasing incidence of PML has recently been reported in patients receiving monoclonal antibody (mAb) therapy for the treatment of autoimmune diseases, particularly those treated with natalizumab, efalizumab and rituximab. Intracellular CD4(+)-ATP-concentration (iATP) functionally reflects cellular immunocompetence and inversely correlates with risk of infections during immunosuppressive therapy. We investigated whether iATP may assist in individualized risk stratification for opportunistic infections during mAb-treatment.

METHODOLOGY/PRINCIPAL FINDINGS

iATP in PHA-stimulated, immunoselected CD4(+)-cells was analyzed using an FDA-approved assay. iATP of mAb-associated PML (natalizumab (n = 8), rituximab (n = 2), efalizumab (n = 1)), or other cases of opportunistic CNS-infections (HIV-associated PML (n = 2), spontaneous PML, PML in a psoriasis patient under fumaric acids, natalizumab-associated herpes simplex encephalitis (n = 1 each)) was reduced by 59% (194.5±29 ng/ml, mean±SEM) in comparison to healthy controls (HC, 479.9±19.8 ng/ml, p<0.0001). iATP in 14 of these 16 patients was at or below 3(rd) percentile of healthy controls, similar to HIV-patients (n = 18). In contrast, CD4(+)-cell numbers were reduced in only 7 of 15 patients, for whom cell counts were available. iATP correlated with mitochondrial transmembrane potential (ΔΨ(m)) (iATP/ΔΨ(m)-correlation:tau = 0.49, p = 0.03). Whereas mean iATP of cross-sectionally analysed natalizumab-treated patients was unaltered (448.7±12 ng/ml, n = 150), iATP was moderately decreased (316.2±26.1 ng/ml, p = 0.04) in patients (n = 7) who had been treated already during the pivotal phase III trials and had received natalizumab for more than 6 years. 2/92 (2%) patients with less than 24 months natalizumab treatment revealed very low iATP at or below the 3(rd) percentile of HC, whereas 10/58 (17%) of the patients treated for more than 24 months had such low iATP-concentrations.

CONCLUSION

Our results suggest that bioenergetic parameters such as iATP may assist in risk stratification under mAb-immunotherapy of autoimmune disorders.

Treatment with natalizumab in relapsing-remitting multiple sclerosis patients induces changes in inflammatory mechanism

Natalizumab is a widely accepted drug for the relapsing–remitting subtype of multiple sclerosis (RRMS). The present longitudinal exploratory study in RRMS patients analyzes the effects of natalizumab treatment on the levels of pro-inflammatory and anti-inflammatory cytokine protein levels and also the frequency and suppressor function of regulatory T cells. Flow cytometry was used to determine cytokines and regulatory T cell frequency while regulatory T cell suppressor function was assayed in vitro at different time-points after starting with natalizumab. Results showed serum levels of pro-inflammatory interferon gamma and interleukin (IL)-12p70, as well as anti-inflammatory IL-4 and IL-10, were elevated just a few hours or days after first IV infusion of natalizumab. Interestingly, other cytokines like IL-5 or IL-13 were also elevated while pro-inflammatory IL-17, IL-2, and IL-1β increased only after a long-term treatment, suggesting different immune mechanisms. In contrast, we did not observe any effect of natalizumab treatment on regulatory T cell frequency or activity. In conclusion, these results suggest natalizumab has other immunological effects beyond VLA-4 interaction and inhibition of CNS extravasation, the relevance of which is as yet unknown and warrants further investigation.

Assessment of the effectiveness and safety of natalizumab for treating relapsing-remitting multiple sclerosis

OBJECTIVE

Assessing the effectiveness and safety of natalizumab for treating relapsing-remitting multiple sclerosis in a tertiary hospital.

METHOD

Observational, prospective study of adult patients treated with natalizumab from May 2007 until February 2009.

TREATMENT

300 mg natalizumab every four weeks. Response criteria: assessment of disease progression, appearance of flare-ups and assessment of magnetic resonance images. Adverse reactions during treatment with natalizumab were recorded.

RESULTS

Thirty patients (73% female); average age 34 ± 8.4 years; mean baseline EDSS 3.4 ± 1.3; number of flare-ups in the past year 2.1 ± 1.2. TREATMENT was discontinued in five patients, due to refusal in one case, ineffectiveness in two cases and anaphylaxis in the other two cases. Fourteen patients completed one year of treatment with satisfactory results. A lower EDSS score by 36%, 47%, 31%, 54% and 28% was obtained at 3, 6, 9, 12 and 15 months of treatment respectively. The prevalence of relapse-free patients was 94%, 76% and 54% at 3, 6 and 12 months. MRI imaging studies in 11 patients one year after they began treatment showed no new lesions. Two patients suffered severe anaphylactic shock and another one had an outbreak of urticaria. The presence of neutralising antibodies was the reason for suspending treatment in 6.6% of the patients.

CONCLUSIONS

The treatment's effectiveness and safety in our patient group suggest that natalizumab is a treatment for refractory patients or those with aggressive types of multiple sclerosis, although we do not yet know about its long-term effects and the evolution of the appearance of neutralising antibodies.

Best practice recommendations for the selection and management of patients with multiple sclerosis receiving natalizumab therapy

Natalizumab, a humanized monoclonal antibody directed against α4-integrin is a first-in-class disease-modifying therapy for the treatment of relapsing multiple sclerosis. Natalizumab is highly effective but has been associated with a risk of progressive multifocal leukoencephalopathy. Since the efficacy of natalizumab in relapsing forms of multiple sclerosis is viewed as superior to first-line agents, a growing number of neurologists are using natalizumab as the treatment of choice for patients with worsening MS. Owing to the recently reported cases of progressive multifocal leukoencephalopathy, a panel of neurologists met in February 2009 to discuss best practices for the use of natalizumab, with the goal of developing consensus-based recommendations on patient management to minimize the risk of progressive multifocal leukoencephalopathy. The panel consisted of a cross section of academic and community neurologists from the United States who treat multiple sclerosis in large centers and have extensive experience with natalizumab (approximating 2000 patient-years combined experience). This paper summarizes the panel's recommendations on the following: (1) appropriate patient selection for natalizumab; (2) routine monitoring and management of adverse events during natalizumab therapy; and (3) clinical vigilance monitoring and risk reduction for progressive multifocal leukoencephalopathy.

High-dose, high-frequency recombinant interferon beta-1a in the treatment of multiple sclerosis

BACKGROUND

There is at present no cure for multiple sclerosis (MS), and existing therapies are designed primarily to prevent lesion formation, decrease the rate and severity of relapses and delay the resulting disability by reducing levels of inflammation.

OBJECTIVE

The aim of this review was to assess the treatment of relapsing MS with particular focus on subcutaneous (s.c.) interferon (IFN) beta-1a.

METHOD

The literature on IFN beta-1a therapy of MS was reviewed based on a PubMed search (English-language publications from 1990) including its pharmacodynamics and pharmacokinetics, clinical efficacy in relapsing MS as shown in placebo-controlled studies and in comparative trials, efficacy in secondary progressive MS, safety and tolerability, and the impact of neutralizing antibodies.

CONCLUSION

The literature suggests that high-dose, high-frequency s.c. IFN beta-1a offers an effective option for treating patients with relapsing MS, with proven long-term safety and tolerability, and has a favourable benefit-to-risk ratio compared with other forms of IFN beta.

Monoclonal antibodies in the therapy of multiple sclerosis: an overview

With the generation of monoclonal antibodies (mAbs), a new therapeutical concept has gained importance. MAbs aim against selective antigens and so have changed our treatment strategies from non-specific to specific. Four therapeuticals have gained importance in the therapy of multiple sclerosis (MS): One has already been approved for therapy (natalizumab), whereas the other three are either in clinical trials or are about to enter phase III studies. Currently, two phase III studies that evaluate the efficacy of alemtuzumab have begun with recruitment (MS CARE I and II). Another mAb (daclizumab) under study is directed to the interleukin-2alpha chain (CD25). Results of clinical trials are promising by reporting reduction of relapses and progression in relapsing remitting and secondary progressive MS accompanied by reduction of new lesions in magnetic resonance imaging. A multicenter randomized controlled trial of daclizumab in MS is going to be initiated. Trials with a humanised antibody directed against the cell surface molecule CD20 are under development. Although the future will emphasise this trend to mAbs, the risks should not be ignored as has been shown in recent news. Still, mAbs have the possibility to revolutionise therapeutical concepts in the treatment of immune-mediated diseases, and will therefore be a useful addition to current therapeutic concepts.

Natalizumab in the treatment of multiple sclerosis

Natalizumab reduced the rate of clinical relapse at one year by 68% and the risk of sustained progression of disability by 42-54% over 2 years in its pivotal phase III trial (AFFIRM) in relapsing-remitting multiple sclerosis (RRMS). Natalizumab is generally well tolerated, but due to rare and potentially fatal side-effects, it was approved with a restricted-distribution format in 2006. Expert statements and the European Medical Agency recommend the use of natalizumab after failure of first-line disease-modifying therapies in patients with relapsing forms of MS. As part of the risk management plan, worldwide extensive safety programmes aim to provide more data on natalizumab safety in clinical practice. At the end of September 2008, 48 000 patients have received natalizumab and 18000 patients are on treatment for at least 1 year. The assessment of risk and benefit is still ongoing.

Disease-modifying agents for multiple sclerosis: recent advances and future prospects

Multiple sclerosis (MS) is a chronic autoimmune disease of the CNS. Currently, six medications are approved for immunmodulatory and immunosuppressive treatment of the relapsing disease course and secondary-progressive MS. In the first part of this review, the pathogenesis of MS and its current treatment options are discussed. During the last decade, our understanding of autoimmunity and the pathogenesis of MS has advanced substantially. This has led to the development of a number of compounds, several of which are currently undergoing clinical testing in phase II and III studies. While current treatment options are only available for parenteral administration, several oral compounds are now in clinical trials, including the immunosuppressive agents cladribine and laquinimod. A novel mode of action has been described for fingolimod, another orally available agent, which inhibits egress of activated lymphocytes from draining lymph nodes. Dimethylfumarate exhibits immunomodulatory as well as immunosuppressive activity when given orally. All of these compounds have successfully shown efficacy, at least in regards to the surrogate marker contrast-enhancing lesions on magnetic resonance imaging. Another class of agents that is highlighted in this review are biological agents, namely monoclonal antibodies (mAb) and recombinant fusion proteins. The humanized mAb daclizumab inhibits T-lymphocyte activation via blockade of the interleukin-2 receptor. Alemtuzumab and rituximab deplete leukocytes and B cells, respectively; the fusion protein atacicept inhibits specific B-cell growth factors resulting in reductions in B-cells and plasma cells. These compounds are currently being tested in phase II and III studies in patients with relapsing MS. The concept of neuro-protection and -regeneration has not advanced to a level where specific compounds have entered clinical testing. However, several agents approved for conditions other than MS are highlighted. Finally, with the advent of these highly potent novel therapies, rare, but potentially serious adverse effects have been noted, namely infections and malignancies. These are critically reviewed and put into perspective.

Basic and escalating immunomodulatory treatments in multiple sclerosis: current therapeutic recommendations

This review updates and extends earlier Consensus Reports related to current basic and escalating immunomodulatory treatments in multiple sclerosis (MS). The recent literature has been extracted for new evidence from randomized controlled trials, open treatment studies and reported expert opinion, both in original articles and reviews, and evaluates indications and safety issues based on published data. After data extraction from published full length publications and critically weighing the evidence and potential impact of the data, the review has been drafted and circulated within the National MS Societies and the European MS Platform to reach consensus within a very large group of European experts, combining evidence-based criteria and expert opinion where evidence is still incomplete. The review also outlines a few areas of controversy and delineates the need for future research.

[Choice of early and escalation treatment options for multiple sclerosis]

Recent advances in understanding of the immunopathogenesis of multiple sclerosis (MS) have led to the development of new treatment options. To date several immunomodulatory agents have been licensed for the treatment of relapsing-remitting MS. However, some debate remains on the optimal time point for initiating therapy. While there is general consensus on the benefit of an early treatment start, the issues of how to define "early MS" and how to identify patients with a "benign" disease course have not yet been finally addressed. Further open questions include the situations of treatment failure and therapeutic escalation. Here we summarize available data from studies on early treatment with immunomodulatory drugs for a first demyelinating event, also referred to as clinically isolated syndrome. Furthermore, options for the escalation of immunomodulatory therapy will be discussed, e.g. with the recently licensed monoclonal antibody natalizumab.

[Open use of natalizumab. Neutralising antibodies and clinical data]

BACKGROUND

Since June 2006 natalizumab has been available for use as monotherapy in relapsing-remitting MS with high disease activity. The AFFIRM study showed the occurrence of persisting and neutralising antinatalizumab antibodies (nAb) in 6% of the patients. We present data revealing the number of nAb-positive patients assessed in our independent laboratory. Additionally we provide retrospective clinical data on the efficacy of natalizumab as escalating immunotherapy.

PATIENTS AND METHODS

Blood samples of patients treated with natalizumab in Germany were tested for nAb using an enzyme-linked immunosorbent assay. If nAb were detectable at a single time point, the according patients were categorised as transiently positive. They were diagnosed as persistently positive if they had nAb at two or more time points which were at least 6 weeks apart. The treating neurologists sending the serum samples were asked to provide clinical data of their patients.

RESULTS

Forty-seven of 593 samples (9.1%) were nAb-positive, 19 of them (3.7%) persistently positive and two (0.3%) transiently. Twenty-six patients (5%) were not retested for nAb, as we did not receive material for confirmatory analysis. Infusion-related adverse events were reported for 53 patients (10.3%). Averages of 2.6 relapses per year were reported previous to natalizumab therapy and 0.3 per year during natalizumab therapy.

CONCLUSION

During natalizumab therapy, testing for nAb should be strongly considered for further therapy decisions and in cases of suspected allergic reaction. Basically the obtained data compare with those of the AFFIRM study. Natalizumab is applied as escalating therapy in MS according to the recommendations of the MSTKG, and it seems to match the expectations in open-label use.

Identification and development of new therapeutics for multiple sclerosis

In recent years, large efforts have been undertaken to establish new therapeutic options for the treatment of multiple sclerosis (MS). So far, all of these strategies more or less specifically target subsets of the immune response in MS, including not only activation and expansion of T cells, their circulation and transmigration over the blood-brain barrier but also other cell types such as B cells and probably also natural killer cells. Here, we review available data on the most promising (at present) new therapeutic approaches. These involve the orally available compounds cladribine, FTY720, fumaric-acid esters, laquinimod and teriflunomide in addition to the monoclonal antibodies alemtuzumab, daclizumab, natalizumab and rituximab. After successful completion of Phase III studies, these compounds might have the potential to add to the current therapeutic armentarium especially for relapsing remitting disease courses in the near future, possibly opening the way to a more individualized treatment.