Natalizumab Therapy Research Articles

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.

Eligibility Criteria to Natalizumab Therapy in Patients with Relapsingremitting Multiple Sclerosis: A Real-life Study in an Italian Population-based Cohort

Background: Many patients with relapsing-remitting MS (RRMS) show a suboptimal response to first-line disease-modifying drugs. In these patients treatment with natalizumab is highly effective, however its use has been limited due to safety concerns. Objective: To evaluate the consistency between the eligibility to natalizumab according to Italian Drug Agency (AIFA), European Medicines Agency (EMA) and Food and Drug Administration (FDA) criteria, and its use in clinical practice. Methods: Medical records of 402 patients from four Italian MS Centres were reviewed to identify patients eligible to natalizumab according to AIFA, EMA, and FDA criteria and verify how many of them were currently treated or had been previously treated in practice. Results: Of 316 RRMS patients, 13.3% were currently or had been previously treated with natalizumab, while additional 7.0%, 14.2%, and 27.2% were not receiving the drug although they were eligible according to AIFA, EMA, and FDA criteria, respectively. Compared to patients treated with natalizumab, subject who were eligible but remained untreated were older and with shorter education. Conclusion: In a cohort of RRMS patients, 20.3%, 27.5%, and 40.5% were eligible to natalizumab according to AIFA, EMA, and FDA, respectively, although only part of them were actually treated.

Natalizumab improves ambulation in relapsing-remitting multiple sclerosis: results from the prospective TIMER study and a retrospective analysis of AFFIRM.

Background and purposeImpaired ambulation is a prominent disabling symptom of multiple sclerosis and can lead to reduced quality of life. Whether natalizumab, a monoclonal antibody shown to reduce disease activity in relapsing−remitting multiple sclerosis, could impact ambulation performance was examined.MethodsA prospective open-label study, TIMER, was conducted in natalizumab-naive patients (n = 215). The timed 25-foot walk (T25FW) and timed 100-m walk (T100MW) were assessed at baseline and at weeks 24 and 48 of natalizumab therapy, together with Expanded Disability Status Scale scores. The effects of natalizumab on T25FW performance were also examined in a retrospective analysis of natalizumab-treated patients (n = 627) and placebo control patients (n = 315) from the AFFIRM study.ResultsIn TIMER, a significant increase from baseline in T25FW speed was seen at week 24 (P = 0.0074) and in T100MW speed at weeks 24 and 48 (both P < 0.001). A greater proportion of patients showed clinically meaningful increases (≥20%) in walking speed on the T100MW (25%) than on the T25FW (13%) at week 48 (P = 0.032). In AFFIRM, natalizumab increased the proportion of patients with ≥20% confirmed improvement in T25FW speed at year 2 by 78% versus placebo (P = 0.0133).ConclusionsNatalizumab increased walking speed in patients with relapsing−remitting multiple sclerosis. The T100MW may be more sensitive to changes in ambulation capacity than the T25FW, and both tests appear to detect clinically meaningful improvements in ambulatory function.

Treatment of progressive multifocal leukoencephalopathy–immune reconstitution inflammatory syndrome with intravenous immunoglobulin in a patient with multiple sclerosis treated with fingolimod after discontinuation of natalizumab

We report a case of progressive multifocal leukoencephalopathy–immune reconstitution inflammatory syndrome in a multiple sclerosis (MS) patient 3.5months after fingolimod commencement and 4.5months after natalizumab (NTZ) cessation. Three cerebrospinal fluid analyses were required before a definitive diagnosis of progressive multifocal leukoencephalopathy was reached. Intravenous immunoglobulin (IVIG) was subsequently given as the sole MS treatment along with mirtazapine and mefloquine. There has been improvement and subsequent clinical stabilization. The notable features are the difficult timing of fingolimod commencement in the context of previous NTZ therapy, the role of repeated cerebrospinal fluid John Cunningham virus analyses in progressive multifocal leukoencephalopathy diagnosis, and the role of IVIG.

CNS infections in 2014: guns, germs, and will

CNS infections in 2014: guns, germs, and will

Natalizumab restores aberrant miRNA expression profile in multiple sclerosis and reveals a critical role for miR-20b.

ObjectiveTo identify microRNAs (miRNAs) regulated by anti-α4 integrin monoclonal antibody therapy (natalizumab) in the peripheral blood of patients with relapsing-remitting (RR) multiple sclerosis (MS) and to confirm their role in experimental settings in vivo.MethodsIn a longitudinal study of 17 RR-MS patients, we investigated blood miRNA expression profiles at baseline and after 1 year of natalizumab therapy by microarray technique and quantitative PCR validation. We compared the baseline expression profiles of these patients to those of 18 age- and sex-matched healthy controls. We confirmed the contribution of resulting candidate miRNAs in an animal model of MS, experimental autoimmune encephalomyelitis (EAE) induced by adoptive transfer of proteolipid protein (PLP)139–151-activated lymphocytes in SJL/J mice or by active immunization of miR-106a∼363-deficient C57BL/6 mice (or wildtype litter mates) with myelin oligodendrocyte glycoprotein (MOG)35–55.ResultsOur longitudinal analysis revealed that miR-18a, miR-20b, miR-29a, and miR-103 were upregulated and predominantly expressed by CD4+ T cells, whereas miR-326 was downregulated upon natalizumab treatment. A comparison of untreated RR-MS patients at baseline with healthy controls revealed that the four natalizumab-upregulated targets were initially downregulated in MS. All confirmed targets showed disease-dependent expression in splenocytes of mice suffering from EAE. Genetic deletion of the miRNA cluster miR-106a∼363 (containing natalizumab-regulated miR-20b) resulted in a more severe EAE course and an in vivo upregulation of the miR-20b target genes rorgt, stat3, and vegfa.InterpretationOur study indicates that natalizumab restores dysregulated miRNA patterns in MS and reveals the contribution of miR-20b in autoimmune demyelination in vivo.

Natalizumab exerts a suppressive effect on surrogates of B cell function in blood and CSF

Background: Natalizumab for multiple sclerosis (MS) increases the risk of progressive multifocal leukoencephalopathy (PML). Objective: We aimed to assess the effect of natalizumab on cellular composition and functional B cell parameters including patients with natalizumab-associated PML (n=37). Methods: Cellular composition by flow cytometry, levels of immunoglobulin (Ig)G/IgM by immunonephelometry, and oligoclonal bands by isoelectric focusing were studied in blood and cerebrospinal fluid. Results: In MS patients treated with natalizumab without PML (n=59) the proportion of CD19+ B cells was higher in blood, but lower in cerebrospinal fluid compared with MS patients not treated with natalizumab (n=17). The CD4/CD8-ratio in cerebrospinal fluid was lower, and IgG and IgM levels as well as the IgG index dropped in longitudinal samples during natalizumab therapy. Oligoclonal bands persisted, but the total amount of the intrathecally produced IgG fraction, and the polyclonal intrathecal IgG reactivity to measles, rubella, and zoster declined. At the time of diagnosis of PML patients with natalizumab-associated PML had low total IgG levels in blood and cerebrospinal fluid. Conclusions: Natalizumab impacts B and T cell distribution and exerts an inhibitory effect on surrogates of B cell function in periphery and in cerebrospinal fluid, potentially contributing to the increased risk of developing PML.

P039 - Natalizumab treatment for multiple sclerosis: Middle East and North Africa regional recommendations for patient selection and monitoring

Background: Natalizumab, a highly specific α4-integrin antagonist, , has recently been registered across the Middle East and North Africa region. It improves clinical and magnetic resonance imaging (MRI) outcomes and reduces the rate of relapse and disability progression in relapsing-remitting multiple sclerosis (MS). Natalizumab is recommended for patients who fail first-line disease-modifying therapy or who have very active disease. Progressive multifocal leukoencephalopathy is a rare, serious adverse event associated with natalizumab. We aim to develop regional recommendations for the selection and monitoring of MS patients to be treated with natalizumab in order to guide local neurological societies. Methods: After a review of available literature, a group of neurologists with expertise in the management of MS met to discuss the evidence and develop regional recommendations to guide appropriate use of natalizumab in the region. Results: Disease breakthrough is defined as either clinical (relapse or disability progression) or radiological activity (new T2 lesion or gadolinium-enhancing lesions on MRI), or a combination of both. Natalizumab is recommended as an escalation therapy in patients with breakthrough disease based on its established efficacy in Phase III studies. Several factors including prior immunosuppressant therapy, anti-John Cunningham virus (JCV) antibody status and patient choice will affect the selection of natalizumab. In highly active MS, natalizumab is considered as a first-line therapy for naive patients with disabling relapses in association with MRI activity. The anti-JCV antibody test is used to assess anti-JCV antibody status and identify the risk of PML. While seronegative patients should continue treatment with natalizumab, anti-JCV antibody testing every 6 months and annual MRI scans are recommended as part of patient monitoring. In seropositive patients, the expected benefits of natalizumab treatment have to be weighed against the risks of PML. Clinical vigilance and follow-up MRI scans remain the cornerstone of monitoring. After 2 years of natalizumab therapy, monitoring should include more frequent MRI scans (every 3–4 months) for seropositive patients, and the risk-benefit ratio should be reassessed and discussed with patients. Conclusions: Recommendations have been developed to guide neurologists in the Middle East and North Africa on patient selection for natalizumab treatment and monitoring.

Risk of Relapse Among Propensity Score Matched Multiple Sclerosis Patients Receiving Natalizumab or Platform Therapy in the US.

Risk of Relapse Among Propensity Score Matched Multiple Sclerosis Patients Receiving Natalizumab or Platform Therapy in the US.

VLA-4 blockade promotes differential routes into human CNS involving PSGL-1 rolling of T cells and MCAM-adhesion of TH17 cells

Focus of this study was the characterization of human T-cell blood–brain-barrier migration and corresponding molecular trafficking signatures. We examined peripheral blood and cerebrospinal fluid immune cells from patients under long-term anti-VLA-4/natalizumab therapy (LTNT), as well as CNS specimens. LTNT patients' cerebrospinal fluid T cells exhibited healthy central-/effector-memory ratios, but lacked CD49d and showed enhanced MCAM expression. LTNT lead to an increase of PSGL-1 expression on peripheral T cells. While VCAM-1 (VLA-4-receptor) was expressed at all CNS barriers, P-selectin (PSGL-1-receptor) was mainly detected at the choroid plexus. Accordingly, in vitro experiments under physiological flow conditions using primary human endothelial cells and LTNT patients' T cells showed increased PSGL-1-mediated rolling and residual adhesion even under VLA-4-blockade. Adhesion of MCAM+/TH17 cells was not affected by VLA-4-blocking alone, but was abrogated when both VLA-4 and MCAM were inhibited. Consistent with these data, MCAM+ cells were detected in white matter lesions, and in gray matter of MS patients. Our data indicate that lymphocyte trafficking into the CNS under VLA-4 blockade can occur by employing the alternative adhesion molecules, PSGL-1 and MCAM, the latter representing an exclusive pathway for TH17 cells to migrate over the blood–brain barrier.

VLA-4 blockade promotes differential routes into human CNS involving PSGL-1 rolling of T cells and MCAM-adhesion of TH17 cells.

The focus of this study is the characterization of human T cell blood-brain barrier migration and corresponding molecular trafficking signatures. We examined peripheral blood and cerebrospinal fluid immune cells from patients under long-term anti-very late antigen-4 (VLA-4)/natalizumab therapy (LTNT) and from CNS specimens. LTNT patients' cerebrospinal fluid T cells exhibited healthy central-/effector-memory ratios, but lacked CD49d and showed enhanced myeloma cell adhesion molecule (MCAM) expression. LTNT led to an increase of PSGL-1 expression on peripheral T cells. Although vascular cell adhesion molecule-1 (VLA-4 receptor) was expressed at all CNS barriers, P-selectin (PSGL-1-receptor) was mainly detected at the choroid plexus. Accordingly, in vitro experiments under physiological flow conditions using primary human endothelial cells and LTNT patients' T cells showed increased PSGL-1-mediated rolling and residual adhesion, even under VLA-4 blockade. Adhesion of MCAM(+)/TH17 cells was not affected by VLA-4 blocking alone, but was abrogated when both VLA-4 and MCAM were inhibited. Consistent with these data, MCAM(+) cells were detected in white matter lesions, and in gray matter of multiple sclerosis patients. Our data indicate that lymphocyte trafficking into the CNS under VLA-4 blockade can occur by using the alternative adhesion molecules, PSGL-1 and MCAM, the latter representing an exclusive pathway for TH17 cells to migrate over the blood-brain barrier.

JC virus urinary excretion and seroprevalence in natalizumab-treated multiple sclerosis patients.

The risk of developing progressive multifocal leukoencephalopathy (PML), as a consequence of infection/reactivation with JC virus (JCV), is consistent in natalizumab-treated multiple sclerosis (MS) patients, with 430 cases of PML reported so far. The risk of PML is higher in JCV seropositive patients, and it is recommended that only MS patients without JCV antibodies should be enrolled in the treatment postulating that they do not have JCV infection.We have studied forty-two natalizumab-treated MS patients, and urine and blood were collected monthly for up to 60 months. JCV and BK virus (BKV) DNA presence was verified using quantitative real-time PCR assays, and serum anti-JCV antibodies were measured with the Stratify and/or Stratify DxSelect tests.JCV and BKV DNA were not found in the blood samples, whereas they were found at least once in the urine of 21 of 42 (50 %) and of 25/42 (59.5 %) patients, respectively. JCV DNA urinary shedding increased up to month 24 of natalizumab treatment (45.2 %), and the effect of time was significant for JCV (p = 0.04), but not for BKV (p = 0.39). JCV viruria and seropositivity did not completely correlate, since three patients shedding JCV DNA in the urine were seronegative according to the serological tests.The results indicated that natalizumab therapy may increase the rate of JCV urinary shedding. Additionally, we confirmed that the identification of JCV carriers cannot solely rely on serological tests, but sensitive methods for viral DNA detection should be adopted to more precisely identify the truly JCV uninfected cases.

Analysis of CD4+ CD8+ double-positive T cells in blood, cerebrospinal fluid and multiple sclerosis lesions.

T cells with a CD4(+) CD8(+) double-positive (DP) phenotype are present in small numbers in the peripheral blood of healthy humans and may have anti-viral capacities. Here we investigate numbers and function of DP T cells in patients with relapsing-remitting multiple sclerosis (MS), either treatment-naive or under therapy with natalizumab. Flow cytometry analysis revealed that frequencies of circulating DP T cells in treatment-naive and natalizumab-treated MS patients are comparable to healthy controls. These cells have a memory phenotype with cytotoxic potential, express high levels of CD49d and are similarly functional in treatment-naive as well as natalizumab-treated MS patients. DP T cells were enriched in the cerebrospinal fluid, but do not invade acutely inflamed MS lesions. In conclusion, DP T cells are functional in MS and may play a role in the immune surveillance of the central nervous system, but do not display functional impairment under natalizumab therapy.

Extended interval dosing of natalizumab: a two-center, 7-year experience.

The enthusiasm for natalizumab, a highly efficacious agent in the treatment of multiple sclerosis (MS), has been tempered by the risks of progressive multifocal leukoencephalopathy associated with its use, and strategies to minimize those risks are of great interest. Extended interval dosing (EID) has been proposed as a way to maintain the efficacy of natalizumab while reducing exposure to it. We reviewed a cohort of patients who received natalizumab at 6-8-week intervals instead of the typical infusions every 4 weeks with the goal to assess if patients on EID had an increase in clinical relapses. This is a retrospective review of all patients with MS treated with natalizumab at two MS centers where patients were offered the opportunity to switch to an EID every 6 or 8 weeks. A total of 361 patients received natalizumab for 22 ± 13 months (minimum duration 6 months). Of these, 96 patients received EID natalizumab at some point for 20 ± 11 months (minimum duration 6 months). Over the study period, there was no significant difference between the relapse rate in the monthly dosing (13%) and the EID (13%) groups of patients. Natalizumab is effective in controlling MS as very few clinical relapses were observed in our dataset. We found that EID did not compromise the treatment effect as measured by relapse rate and no significant breakthrough disease activity was observed. EID is an optional regimen for maintenance natalizumab therapy, but prospective studies are warranted to determine its efficacy.

Cloning of the first human anti-JCPyV/VP1 neutralizing monoclonal antibody: Epitope definition and implications in risk stratification of patients under natalizumab therapy

JC virus (JCPyV) has gained novel clinical importance as cause of progressive multifocal leukoencephalopathy (PML), a rare demyelinating disease recently associated to immunomodulatory drugs, such as natalizumab used in multiple sclerosis (MS) cases. Little is known about the mechanisms leading to PML, and this makes the need of PML risk stratification among natalizumab-treated patients very compelling. Clinical and laboratory-based risk-stratification markers have been proposed, one of these is represented by the JCPyV-seropositive status, which includes about 54% of MS patients. We recently proposed to investigate the possible protective role of neutralizing humoral immune response in preventing JCPyV reactivation. In this proof-of-concept study, by cloning the first human monoclonal antibody (GRE1) directed against a neutralizing epitope on JCPyV/VP1, we optimized a robust anti-JCPyV neutralization assay. This allowed us to evaluate the neutralizing activity in JCPyV-positive sera from MS patients, demonstrating the lack of correlation between the level of anti-JCPyV antibody and anti-JCPyV neutralizing activity. Relevant consequences may derive from future clinical studies induced by these findings; indeed the study of the serum anti-JCPyV neutralizing activity could allow not only a better risk stratification of the patients during natalizumab treatment, but also a better understanding of the pathophysiological mechanisms leading to PML, highlighting the contribution of peripheral versus central nervous system JCPyV reactivation. Noteworthy, the availability of GRE1 could allow the design of novel immunoprophylactic strategies during the immunomodulatory treatment.

Blood miRNA expression pattern is a possible risk marker for natalizumab-associated progressive multifocal leukoencephalopathy in multiple sclerosis patients

Background: Natalizumab has shown its efficacy in reducing multiple sclerosis (MS) relapses and progression of disability; however, it has been associated with an increased risk of developing progressive multifocal leukoencephalopathy (PML). The differential expression of microRNA (miRNA), the small non-coding RNAs that regulate gene expression, in natalizumab-treated patients has been reported and miRNA have also been described as good candidates for disease biomarkers. Objective: To characterize the effect of natalizumab therapy on the miRNA expression pattern and to search for miRNAs that can predict PML on an individual basis. Methods: The expression of 754 microRNAs was measured in blood samples from 19 relapsing–remitting MS patients at three time points during natalizumab therapy, using TaqMan OpenArray panels. Two patients included in this study developed PML after more than 2 years of therapy. Results: We found that the expression level of three miRNAs (let-7c, miR-125a-5p and miR-642) was affected after 6 months of therapy (t6). Furthermore, we observed a differential expression of another three miRNAs (miR-320, miR-320b and miR-629) between the PML and non-PML groups after 12 months of treatment (t12); and a positive correlation was found between therapy time and the expression of miR-320. Conclusions: Natalizumab modified the expression levels of three miRNAs after a 6-month treatment. We suggest miR-320, miR-320b and miR-629 as possible biomarkers for individual PML risk assessment.

Predictors for multiple sclerosis relapses after switching from natalizumab to fingolimod

Background: Risks of natalizumab (NAT) therapy have to be weighed against disease recurrence after stopping NAT. Objectives: The objective of this paper is to identify risk factors for recurrence of relapses after switching from NAT to fingolimod (FTY) in relapsing–remitting multiple sclerosis (RRMS). Methods: Patients (n = 33) were treated with NAT for ≥1 year, and then switched to FTY within 24 weeks (mean follow-up on FTY 81.1 (SD 26.5) weeks). Annual relapse rates (ARR) and Expanded Disability Status Scale scores (EDSS) were assessed. Descriptive statistics, univariate logistic regression analysis, and receiver operating characteristic curves were conducted. Results: Overall, 20 patients (61%) had relapses after discontinuation of NAT and 16 (48%) during FTY therapy. The maximum incidence of relapses occurred between weeks 13–24 post-NAT. The last EDSS during the switching period predicted relapses during subsequent FTY therapy. EDSS >3 separated most powerfully between the groups (sensitivity 64%, specificity 88%) and significantly predicted relapses (relative risk 3.27, 95% CI: 1.5–7.3). Seventy-five percent of patients with EDSS ≤ 3 remained free of relapses, compared to 18% of patients with EDSS >3. Conclusions: There was an increase of the ARR in the first year after switching from NAT to FTY. Last EDSS during the switching period was a predictor of relapses during FTY.

Does risk stratification decrease the risk of natalizumab-associated PML? Where is the evidence?

The use of natalizumab has likely been limited by its association with progressive multifocal leukoencephalopathy (PML), an infection caused by the human polyomavirus John Cunningham (JC). Three factors were recently identified that contribute to the overall risk of natalizumab-associated PML: (1) Positive serostatus for anti-JCV antibodies, (2) prior use of immunosuppressants, and (3) duration of natalizumab therapy. This risk stratification algorithm has not led to a reduction in the incidence of PML in natalizumab-treated patients with multiple sclerosis between April 2010 and February 2014. This observation may appear perplexing, as treatment duration and JCV serostatus are modifiable risk factors. Potential reasons for the lack of success of companion diagnostics that determine the overall risk of natalizumab-associated PML are discussed.

Unusual deterioration in a patient with multiple sclerosis on natalizumab therapy

Natalizumab is an effective treatment in patients with highly active relapsing-remitting multiple sclerosis (RRMS). However, its positive therapeutic effects have to be weighed against the potential serious adverse event of progressive multifocal leukoencephalopathy (PML). Thus, whenever patients with MS on natalizumab develop uncommon and progressive neurologic symptoms, the suspicion of PML has to be raised. The risk of PML becomes higher with increasing duration of natalizumab treatment, prior immunosuppressive treatment, and JC virus (JCV) antibody seropositivity.1 We here report a case of MS in which unusual symptoms in the context of 5 years of natalizumab treatment and seroconversion to JCV antibody positivity led to the initial suspicion of PML and a final diagnosis of Creutzfeldt-Jakob disease (CJD).

Long-term follow-up of peripheral lymphocyte subsets in a cohort of multiple sclerosis patients treated with natalizumab

Natalizumab, an anti-alpha4 integrin monoclonal antibody inhibiting the adhesion of lymphocytes to the endothelium, is a widely accepted drug treatment for relapsing-remitting multiple sclerosis (RRMS). A peripheral increase of T and B lymphocytes has already been observed as an early treatment effect. This retrospective observational study was aimed to evaluate the peripheral lymphocyte subsets during a long-term treatment follow-up. We included 23 RRMS patients treated with natalizumab for at least 24-48 months who had pretreatment lymphocyte evaluation. Baseline values of lymphocyte subsets and CD4/CD8 ratio did not differ significantly from the 23 matched healthy subjects. The periodic (every 3-6 months) assessment of immune cell subsets was performed by flow cytometry on peripheral blood collected before drug injection. Therapy with natalizumab was confirmed to be effective during the observational period. For all patients, the increase in lymphocytes during natalizumab therapy compared to baseline at every assessment was significantly higher compared to that of overall white blood cells (2·1- and 1·3-fold, respectively, P < 0·0001). Both T cell subsets were proportionally modified and the CD4/CD8 ratio did not change significantly, while B cells increased significantly compared to T and NK cells (3·2-, 1·88- and 1·92-fold, respectively, P < 0·0001). These changes remained constant throughout the 25-48-month period of therapy. In conclusion, effective natalizumab treatment of RRMS patients was associated with the persistence of its biological effects through a stable increase of peripheral lymphocytes, mainly B cells, and an unchanged proportion of T cell subsets in long-term follow-up.