Natalizumab-treated patients at high risk for PML persistently excrete JC polyomavirus

Progressive Multifocal Leukoencephalopathy Incidence and Risk Stratification Among Natalizumab Users in France

Importance

Risk of developing progressive multifocal leukoencephalopathy (PML) is the major barrier to using natalizumab for patients with multiple sclerosis (MS). To date, the association of risk stratification with PML incidence has not been evaluated.

Objective

To describe the temporal evolution of PML incidence in France before and after introduction of risk minimization recommendations in 2013.

Design, Setting, and Participants

This observational study used data in the MS registry OFSEP (Observatoire Français de la Sclérose en Plaques) collected between April 15, 2007, and December 31, 2016, by participating MS expert centers and MS-dedicated networks of neurologists in France. Patients with an MS diagnosis according to current criteria, regardless of age, were eligible, and those exposed to at least 1 natalizumab infusion (n = 6318) were included in the at-risk population. A questionnaire was sent to all centers, asking for a description of their practice regarding PML risk stratification. Data were analyzed in July 2018.

Exposures

Time from the first natalizumab infusion to the occurrence of PML, natalizumab discontinuation plus 6 months, or the last clinical evaluation.

Main Outcomes and Measures

Incidence was the number of PML cases reported relative to the person-years exposed to natalizumab. A Poisson regression model for the 2007 to 2016 period estimated the annual variation in incidence and incidence rate ratio (IRR), adjusted for sex and age at treatment initiation and stratified by period (2007-2013 and 2013-2016).

Results

In total, 6318 patients were exposed to natalizumab during the study period, of whom 4682 (74.1%) were female, with a mean (SD [range]) age at MS onset of 28.5 (9.1 [1.1-72.4]) years; 45 confirmed incident cases of PML were diagnosed in 22 414 person-years of exposure. The crude incidence rate for the whole 2007 to 2016 period was 2.00 (95% CI, 1.46-2.69) per 1000 patient-years. Incidence significantly increased by 45.3% (IRR, 1.45; 95% CI, 1.15-1.83; P = .001) each year before 2013 and decreased by 23.0% (IRR, 0.77; 95% CI, 0.61-0.97; P = .03) each year from 2013 to 2016.

Conclusions and Relevance

The results of this study suggest, for the first time, a decrease in natalizumab-associated PML incidence since 2013 in France that may be associated with a generalized use of John Cunningham virus serologic test results; this finding appears to support the continuation and reinforcement of educational activities and risk-minimization strategies in the management of disease-modifying therapies for multiple sclerosis.

JC Polyomavirus, progressive multifocal leukoencephalopathy and immune reconstitution inflammatory syndrome: a review

The human neurotropic virus JC Polyomavirus, a member of the Polyomaviridae family, is the opportunistic infectious agent causing progressive multifocal leukoencephalopathy, typically in immunocompromised individuals. The spectrum of underlying reasons for the systemic immunosuppression that permits JCV infection in the central nervous system has evolved over the past 2 decades, and therapeutic immunosuppression arousing JCV infection in the brain has become increasingly prominent as a trigger for PML. Effective immune restoration subsequent to human immunodeficiency virus-related suppression is now recognized as a cause for unexpected deterioration of symptoms in patients with PML, secondary to a rebound inflammatory phenomenon called immune reconstitution inflammatory syndrome, resulting in significantly increased morbidity and mortality in a disease already infamous for its lethality. This review addresses current knowledge regarding JC Polyomavirus, progressive multifocal leukoencephalopathy, progressive multifocal leukoencephalopathy-related immune reconstitution inflammatory syndrome, and the immunocompromised states that incite JC Polyomavirus central nervous system infection, and discusses prospects for the future management of these conditions.

Sequencing of disease-modifying therapies for relapsing-remitting multiple sclerosis: a theoretical approach to optimizing treatment

Multiple sclerosis (MS) is a chronic disease which usually begins in young adulthood and is a lifelong condition. Individuals with MS experience physical and cognitive disability resulting from inflammation and demyelination in the central nervous system. Over the past decade, several disease-modifying therapies (DMTs) have been approved for the management of relapsing-remitting MS (RRMS), which is the most prevalent phenotype. The chronic nature of the disease and the multiple treatment options make benefit-risk-based sequencing of therapy essential to ensure optimal care. The efficacy and short- and long-term risks of treatment differ for each DMT due to their different mechanism of action on the immune system. While transitioning between DMTs, in addition to immune system effects, factors such as age, disease duration and severity, disability status, monitoring requirements, preference for the route of administration, and family planning play an important role. Determining a treatment strategy is therefore challenging as it requires careful consideration of the differences in efficacy, safety and tolerability, while at the same time minimizing risks of immune modulation. In this review, we discuss a sequencing approach for treating RRMS, with importance given to the long-term risks and individual preference when devising a treatment plan. Evidence-based strategies to counter breakthrough disease are also addressed.

Diagnosis and Treatment of Progressive Multifocal Leukoencephalopathy Associated with Multiple Sclerosis Therapies

Progressive multifocal leukoencephalopathy (PML) is a rare, but serious, complication encountered in patients treated with a select number of disease-modifying therapies (DMTs) utilized in treating multiple sclerosis (MS). PML results from a viral infection in the brain for which the only demonstrated effective therapy is restoring the perturbed immune system-typically achieved in the patient with MS by removing the offending therapeutic agent or, in the case of HIV-associated PML, treatment with highly active antiretroviral therapies. Other therapies for PML remain either ineffective or experimental. Significant work to understand the virus and host interaction has been undertaken, but lack of an animal model for the disorder has significantly hindered progress, especially with respect to development of treatments. Strategies to limit risk of PML with natalizumab, a drug that carries a uniquely high risk for the development of the disorder, have been developed. Identifying factors such as positive JC virus antibody status that increase PML risk, at least in theory, should decrease the incidence rate of the disease. Whether other risk factors for PML can be identified and validated or unique strategies should be employed in association with other DMTs that predispose to PML and whether this has a salutary effect on outcome remains to be demonstrated. Identifying PML early, then promptly eliminating drug in the case of natalizumab-associated PML has demonstrated better outcomes, but the complication of PML continues to carry significant morbidity and mortality. While the scientific community has yet to identify targeted therapy with proven efficacy against JCV or PML there are several candidates being studied.

Progressive multifocal leukoencephalopathy and rheumatoid arthritis treatments

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system due to reactivation of the JC virus (JCV). PML is extremely uncommon despite the high prevalence of the virus in the general population. No specific treatment is available, and the prognosis is bleak. The diagnosis is based on brain imaging findings, detection of the JCV genome in cerebrospinal fluid samples and, in some cases, histological studies of the brain lesions. The pathophysiological mechanisms that drive the development of PML are incompletely understood. However, a consistent feature is the presence of a predisposing factor, most notably immunosuppression. The risk of developing PML varies with the underlying disease (e.g., HIV infection or autoimmune disease) and with the drugs used to treat them. Biologics have been ranked according to the risk of PML during their use. Natalizumab, a monoclonal antibody given to treat multiple sclerosis, is among the drugs associated with a high risk of PML. Patients given natalizumab are now closely monitored based on anti-JCV antibody titers and index values. In rheumatology, the expanding use of biologics has led to an increase in cases of PML, with rituximab being associated with the highest risk. Given the absence of specific recommendations, exhaustive registries and postmarketing observational studies are urgently needed to gauge the risk of PML according to the underlying disease and drug treatments, with the goal of defining optimal monitoring protocols.

Nebulization of RNS60, a Physically-Modified Saline, Attenuates the Adoptive Transfer of Experimental Allergic Encephalomyelitis in Mice: Implications for Multiple Sclerosis Therapy

Developing a new and effective therapeutic approach against multiple sclerosis (MS) is always an important area of research. RNS60 is a bioactive aqueous solution generated by subjecting normal saline to Taylor-Couette-Poiseuille flow under elevated oxygen pressure. Recently we have demonstrated that RNS60, administered through intraperitoneal injection, ameliorated clinical symptoms and disease progression of experimental allergic encephalomyelitis (EAE), an animal model of MS. Since the intravenous route is not preferred for treating a chronic condition, we tested if nebulization of RNS60 could attenuate the disease process of adoptively-transferred EAE in mice. Although we could not directly image RNS60 after nebulization, nebulized Alexa680 reached spleen, spinal cord and different parts of the brain. Nebulization of RNS60 starting from the acute phase attenuated clinical symptoms of relapsing-remitting EAE in female SJL/J mice. RNS60 nebulization also inhibited perivascular cuffing, maintained the integrity of blood-brain and blood-spinal cord barriers, suppressed inflammation, normalized the expression of myelin genes, and blocked demyelination in the CNS of EAE mice. On the immunomodulatory front, nebulization of RNS60 to EAE mice led to the enrichment of anti-autoimmune regulatory T cells (Tregs) and suppression of autoimmune Th17 cells. Together, these results suggest that nebulization of RNS60 may be used to control aberrant immune responses in MS and other autoimmune disorders.

Classifying PML risk with disease modifying therapies

OBJECTIVE

To catalogue the risk of PML with the currently available disease modifying therapies (DMTs) for multiple sclerosis (MS).

BACKGROUND

All DMTs perturb the immune system in some fashion. Natalizumab, a highly effective DMT, has been associated with a significant risk of PML. Fingolimod and dimethyl fumarate have also been unquestionably associated with a risk of PML in the MS population. Concerns about PML risk with other DMTs have arisen due to their mechanism of action and pharmacological parallel to other agents with known PML risk. A method of contextualizing PML risk for DMTs is warranted.

METHODS

Classification of PML risk was predicated on three criteria:: 1) whether the underlying condition being treated predisposes to PML in the absence of the drug; 2) the latency from initiation of the drug to the development of PML; and 3) the frequency with which PML is observed.

RESULTS

Among the DMTs, natalizumab occupies a place of its own with respect to PML risk. Significantly lesser degrees of risk exist for fingolimod and dimethyl fumarate. Whether PML will be observed with other DMTs in use for MS, such as, rituximab, teriflunomide, and alemtuzumab, remains uncertain.

DISCUSSION

A logical classification for stratifying DMT PML risk is important for both the physician and patient in contextualizing risk/benefit ratios. As additional experience accumulates regarding PML and the DMTs, this early effort will undoubtedly require revisiting.