Natalizumab discontinuation in patients with multiple sclerosis: Profiling risk and benefits at therapeutic crossroads

Risk of secondary progression in patients with highly active multiple sclerosis treated with natalizumab: a real-life study

BACKGROUND

one of the most important therapeutic goals in relapse-onset multiple sclerosis is to preclude conversion to secondary progression. Our objective was to determine the risk of progression associated with natalizumab treatment in an registry-based cohort of patients and to identify determinant factors.

METHODS

Patients with relapse-onset multiple sclerosis from the Registre Lorrain des Scléroses en Plaques (ReLSEP) were included if they had received one infusion of natalizumab between 2002 and 2021. The risk of secondary progression was determined using a standardized definition and a multi-state estimator to account for the possibility of stopping natalizumab before progression, and analyzed with multivariate Cox models.

RESULTS

574 patients were followed up for a median of 6.7 years. Of the 304 who stopped NTZ before progression onset, the probabilities (95% confidence interval) to convert to progression after 1, 2, 5 and 10 years were 3.2% (2.0-4.8%), 5.3% (3.6-7.3%), 17.5% (14.3-21.3%) and 28.3% (23.7-33.7%), respectively. Discontinuation of NTZ during follow-up was significantly associated with an increased risk of conversion in case of no resumption of a highly active treatment thereafter (adjusted hazard ratio = 2.7; 95% confidence interval 1.5-4.9; p = 0.001). The use of such a treatment was associated with a lower risk of progression (adjusted hazard ratio = 0.42; 95% confidence interval 0.23-0.79; p = 0.007).

CONCLUSION

the risk of conversion to secondary progression associated with natalizumab treatment is relatively low but increases in case of natalizumab discontinuation in the absence of switch to highly active immunosuppressant.

Factors determining the treatment ineffectiveness in multiple sclerosis

BACKGROUND

In patients with multiple sclerosis (MS), the suboptimal response should be well evaluated at every step of treatment.

REVIEW SUMMARY

Determining patients with moderate or high activity and suboptimal response to treatment (clinical variables, MRI activity, perception of the patient and physician, side effects, serious risks, etc.) and timely intervention in the treatment are very important in achieving the desired effectiveness in the long term. Within the early stages, there is a limited time interval for effective treatment of MS patients. During this time, intervention is critical to achieve long-term positive results. After diagnosis, an early and individualized specific treatment for MS, depending on the severity of the disease, can prevent radiological and physical disability in the medium/long term.

CONCLUSIONS

With the emergence of a number of new treatments each with their own benefits and risks, a change in the nature of interactions between patients and MS physicians has been anticipated and will be required in the patient-related clinical decision-making process in the developing MS landscape.

PML risk is the main factor driving the choice of discontinuing natalizumab in a large multiple sclerosis population: results from an Italian multicenter retrospective study

BACKGROUND

Natalizumab (NTZ) is an effective treatment for relapsing-remitting multiple sclerosis (RRMS). However, patients and physicians may consider discontinuing NTZ therapy due to safety or efficacy issues. The aim of our study was to evaluate the NTZ discontinuation rate and reasons of discontinuation in a large Italian population of RRMS patients.

MATERIALS AND METHODS

The data were extracted from the Italian MS registry in May 2018 and were collected from 51,845 patients in 69 Italian multiple sclerosis centers. MS patients with at least one NTZ infusion in the period between June 1st 2012 to May 15th 2018 were included. Discontinuation rates at each time point were calculated. Reasons for NTZ discontinuation were classified as "lack of efficacy", "progressive multifocal leukoencephalopathy (PML) risk" or "other".

RESULTS

Out of 51,845, 5151 patients, 3019 (58.6%) females, with a mean age of 43.6 ± 10.1 years (median 40), were analyzed. Out of 2037 (39.5%) who discontinued NTZ, a significantly higher percentage suspended NTZ because of PML risk compared to lack of efficacy [1682 (32.7% of 5151) vs 221 (4.3%), p < 0.001]; other reasons were identified for 99 (1.9%) patients. Patients discontinuing treatment were older, had longer disease duration and worse EDSS at the time of NTZ initiation and at last follow-up on NTZ treatment. The JCV index and EDSS at baseline were predictors for stopping therapy (HR 2.94, 95% CI 1.22-4.75; p = 0.02; HR 1.36, 95% CI 1.18-5.41; p = 0.04).

CONCLUSIONS

Roughly 60% of MS patients stayed on NTZ treatment during the observation period. For those patients in whom NTZ discontinuation was required, it was mainly due to PML concerns.

Long-term real-world evidence for sustained clinical benefits of fingolimod following switch from natalizumab

BACKGROUND

The risk of progressive multifocal leukoencephalopathy limits the duration over which patients can receive natalizumab before requiring a switch to other therapies such as fingolimod. To date, no studies have assessed the long-term real-world effectiveness and safety of fingolimod following a switch from natalizumab. We aimed to investigate the benefit-risk profile of fingolimod over 48 months in patients switching from natalizumab, and the impact of washout duration after natalizumab discontinuation on outcomes during fingolimod treatment.

METHODS

This analysis used data from PANGAEA, an ongoing German multicenter, prospective, non-interventional, observational study. In total, 3912 patients were included: 530 had switched from natalizumab (natalizumab subpopulation), and a reference population of 3382 had switched from other treatments or were treatment-naïve (non-natalizumab subpopulation). The natalizumab subpopulation was stratified by washout duration (30-89 days, 90-149 days, and ≥ 150 days) prior to fingolimod initiation.

RESULTS

In the natalizumab subpopulation over 48 months of fingolimod treatment, 58.2% (n = 227/390) of patients remained on fingolimod. Over this period, mean annualized relapse rates (ARRs) and proportions of patients who relapsed were similar across washout durations, and ranged from 0.455 (95% confidence interval [CI]: 0.363-0.571) to 0.546 (95% CI: 0.446-0.669) and 54.1% (n = 92/170) to 60.2% (n = 127/211), respectively. Overall, 17.1% (n = 36/211) had 6-month confirmed disability worsening. In the non-natalizumab subpopulation, ARR was 0.300, 40.9% (n = 1325/3237) of patients relapsed, and a similar proportion to the natalizumab subpopulation had 6-month disability worsening (16.6% [n = 232/1394]). In both subpopulations, the safety profile of fingolimod was consistent with that observed in randomized controlled trials.

CONCLUSIONS

In patients discontinuing natalizumab, fingolimod has a favorable benefit-risk profile over 48 months. These findings also suggest using a short washout following natalizumab discontinuation, consistent with guidelines and current clinical practice in Germany.

Immunological Aspects of Approved MS Therapeutics

Multiple sclerosis (MS) is the most common neurological immune-mediated disease leading to disability in young adults. The outcome of the disease is unpredictable, and over time, neurological disabilities accumulate. Interferon beta-1b was the first drug to be approved in the 1990s for relapsing-remitting MS to modulate the course of the disease. Over the past two decades, the treatment landscape has changed tremendously. Currently, more than a dozen drugs representing 1 substances with different mechanisms of action have been approved (interferon beta preparations, glatiramer acetate, fingolimod, siponimod, mitoxantrone, teriflunomide, dimethyl fumarate, cladribine, alemtuzumab, ocrelizumab, and natalizumab). Ocrelizumab was the first medication to be approved for primary progressive MS. The objective of this review is to present the modes of action of these drugs and their effects on the immunopathogenesis of MS. Each agent's clinical development and potential side effects are discussed.

Post-natalizumab disease reactivation in multiple sclerosis: systematic review and meta-analysis

Background

Natalizumab (NTZ) is sometimes discontinued in patients with multiple sclerosis, mainly due to concerns about the risk of progressive multifocal leukoencephalopathy. However, NTZ interruption may result in recrudescence of disease activity.

Objective

The objective of this study was to summarize the available evidence about NTZ discontinuation and to identify which patients will experience post-NTZ disease reactivation through meta-analysis of existing literature data.

Methods

PubMed was searched for articles reporting the effects of NTZ withdrawal in adult patients (⩾18 years) with relapsing-remitting multiple sclerosis (RRMS). Definition of disease activity following NTZ discontinuation, proportion of patients who experienced post-NTZ disease reactivation, and timing to NTZ discontinuation to disease reactivation were systematically reviewed. A generic inverse variance with random effect was used to calculate the weighted effect of patients' clinical characteristics on the risk of post-NTZ disease reactivation, defined as the occurrence of at least one relapse.

Results

The original search identified 205 publications. Thirty-five articles were included in the systematic review. We found a high level of heterogeneity across studies in terms of sample size (10 to 1866 patients), baseline patient characteristics, follow up (1-24 months), outcome measures (clinical and/or radiological), and definition of post-NTZ disease reactivation or rebound. Clinical relapses were observed in 9-80% of patients and peaked at 4-7 months, whereas radiological disease activity was observed in 7-87% of patients starting at 6 weeks following NTZ discontinuation. The meta-analysis of six articles, yielding a total of 1183 patients, revealed that younger age, higher number of relapses and gadolinium-enhanced lesions before treatment start, and fewer NTZ infusions were associated with increased risk for post-NTZ disease reactivation (p ⩽ 0.05).

Conclusions

Results from the present review and meta-analysis can help to profile patients who are at greater risk of post-NTZ disease reactivation. However, potential reporting bias and variability in selected studies should be taken into account when interpreting our data.

Post-natalizumab disease reactivation in multiple sclerosis: systematic review and meta-analysis

Background:

Natalizumab (NTZ) is sometimes discontinued in patients with multiple sclerosis, mainly due to concerns about the risk of progressive multifocal leukoencephalopathy. However, NTZ interruption may result in recrudescence of disease activity.

Objective:

The objective of this study was to summarize the available evidence about NTZ discontinuation and to identify which patients will experience post-NTZ disease reactivation through meta-analysis of existing literature data.

Methods:

PubMed was searched for articles reporting the effects of NTZ withdrawal in adult patients (⩾18 years) with relapsing–remitting multiple sclerosis (RRMS). Definition of disease activity following NTZ discontinuation, proportion of patients who experienced post-NTZ disease reactivation, and timing to NTZ discontinuation to disease reactivation were systematically reviewed. A generic inverse variance with random effect was used to calculate the weighted effect of patients’ clinical characteristics on the risk of post-NTZ disease reactivation, defined as the occurrence of at least one relapse.

Results:

The original search identified 205 publications. Thirty-five articles were included in the systematic review. We found a high level of heterogeneity across studies in terms of sample size (10 to 1866 patients), baseline patient characteristics, follow up (1–24 months), outcome measures (clinical and/or radiological), and definition of post-NTZ disease reactivation or rebound. Clinical relapses were observed in 9–80% of patients and peaked at 4–7 months, whereas radiological disease activity was observed in 7–87% of patients starting at 6 weeks following NTZ discontinuation. The meta-analysis of six articles, yielding a total of 1183 patients, revealed that younger age, higher number of relapses and gadolinium-enhanced lesions before treatment start, and fewer NTZ infusions were associated with increased risk for post-NTZ disease reactivation (p ⩽ 0.05).

Conclusions:

Results from the present review and meta-analysis can help to profile patients who are at greater risk of post-NTZ disease reactivation. However, potential reporting bias and variability in selected studies should be taken into account when interpreting our data.

Early diagnosis of progressive multifocal leucoencephalopathy: longitudinal lesion evolution

OBJECTIVE

Early diagnosis of natalizumab-related progressive multifocal leucoencephalopathy (NTZ-PML) in multiple sclerosis has been deemed a major priority by the regulatory agencies but has yet to become a reality. The current paper aims to: (1) investigate whether patients with NTZ-PML pass through a prolonged presymptomatic phase with MRI abnormalities, (2) estimate the longitudinal PML lesion volume increase during the presymptomatic phase and (3) estimate the presymptomatic phase length and its impact on therapy duration as a risk stratification parameter.

METHODS

All Italian patients who developed NTZ-PML between 2009 and 2018 were included. The data of patients with available prediagnostic MRI were analysed (n=41). Detailed clinical and neuroradiological information was available for each participant.

RESULTS

(1) PML lesions were detectable in the presymptomatic phase in 32/41 (78%) patients; (ii) the lesion volume increased by 62.8 % for each month spent in the prediagnostic phase; (3) the prediagnostic phase length was 150.8±74.9 days; (4) PML MRI features were detectable before the 24th month of therapy in 31.7 % of patients in our cohort.

CONCLUSIONS

Considering the latency of PML clinical manifestation, the presymptomatic phase length supports the usefulness of MRI surveillance every 3-4  months. Early diagnosis could prompt a better outcome for patients due to the relationship between lesion volume and JC virus infection. The insight from this study might also have an impact on risk stratification algorithms, as therapy duration as a parameter of stratification appears to need reassessment.

Natalizumab Treatment for Relapsing-Remitting Multiple Sclerosis: The Experience From Saudi Arabia

BACKGROUND

Natalizumab is the first targeted humanized monoclonal antibody to be approved for the treatment of relapsing-remitting multiple sclerosis (RRMS). Natalizumab appears to be more effective than current first-line disease-modifying therapies. In our study, we aimed to evaluate the outcome of Saudi patients with active RRMS treated with natalizumab and compare the results with other outcomes in the Gulf and international trials.

METHODS

We conducted a retrospective single-center observational study involving 32 patients with RRMS at King Abdulaziz Medical City in Jeddah, Saudi Arabia. The inclusion criteria included all patients diagnosed with RRMS according to the revised McDonald criteria who are currently receiving or received natalizumab treatment in the past for a minimum of 6 months.

RESULTS

The mean baseline Expanded Disability Status Scale score was 4.50 ± 1.80 (range, 1.5-6; median, 5), whereas the mean Expanded Disability Status Scale at the follow-up was 4.02 ± 2.08 (range, 1-6; median, 4.25) (P = 0.3274). The mean annualized relapse rate was significantly reduced from 2.41 ± 2.48 at baseline to 0.16 ± 0.37 at the last follow-up (P < 0.0001). Twenty-seven patients (84.4%) had no relapses since the treatment with natalizumab was started, whereas 5 patients (15.6%) had only 1 relapse. In addition to clinically measurable improvement, radiological improvement was observed through magnetic resonance imaging. Magnetic resonance imaging activity was significantly improved at follow-up magnetic resonance imaging studies when compared with baseline.

CONCLUSIONS

Our single-center study in Saudi Arabia provides further support for the efficacy of natalizumab in the clinical practice setting. The sharp decrease in relapse rate and progression of disability following the initiation of natalizumab treatment was similar to other observational studies conducted in different countries across the globe. Natalizumab was a satisfactory therapy for the management of our MS population, both from the patients' and the physicians' perspectives.

Long-term evaluation of NEDA-3 status in relapsing-remitting multiple sclerosis patients after switching from natalizumab to fingolimod

Background:

Natalizumab significantly reduces the disease activity in patients with relapsing-remitting multiple sclerosis but due to the risk of progressive multifocal leukoencephalopathy it is often discontinued. Fingolimod is seen as an alternative, but there are no long-term analyses of the efficacy of fingolimod in this setting using the no evidence of disease activity (NEDA)-3 criteria. We provide an assessment of patients who discontinued natalizumab and switched to fingolimod or other treatments by evaluating the proportion of patients who fulfil NEDA-3 criteria after prolonged follow-up periods.

Methods:

We conducted a retrospective observational study of multiple sclerosis patients, who were treated with continuous natalizumab or who had switched to fingolimod or other treatments after natalizumab discontinuation. We assessed NEDA-3 status, annual relapse rate and determined the odds ratio between disease course after treatment switch and other patient and treatment characteristics.

Results:

A total of 61 patients on continuous natalizumab treatment and 53 patients who switched from natalizumab to fingolimod or other treatments were accompanied for up to 5 years. While the proportion of natalizumab patients fulfilling NEDA-3 criteria remained stable at 90% during the entire follow-up period, the proportion of patients switching to fingolimod or other therapies dropped to 76.7% in the first year after discontinuation, and to 50% in the years thereafter. While the median Expanded Disability Status Scale remained stable and the percentage of relapsing patients did not change significantly, recurring magnetic resonance imaging activity was found in up to 42% of the patients after switching from natalizumab to other treatments. New disease activity was significantly correlated with extended treatment gap between natalizumab discontinuation and the start of a new therapy.

Discussion:

Patients remain clinically stable after discontinuing natalizumab and switching to other therapies. However, when considering NEDA-3 criteria, a considerable proportion of patients show disease reactivation. Careful monitoring and early evaluation of alternatives is necessary after switching from natalizumab to other treatments.

The role of natalizumab in the treatment of multiple sclerosis: benefits and risks

Natalizumab, a monoclonal antibody that blocks lymphocyte infiltration in the central nervous system, is a valuable tool in the treatment of relapsing forms of multiple sclerosis (MS). In a phase III clinical trial comparing natalizumab with placebo over 2 years, natalizumab reduced annualized relapse rate by 68%, 12-week confirmed disability progression by 42%, and reduced contrast-enhancing lesions by 92%. In post hoc analyses, natalizumab treatment was associated with 37% of patients achieving no evidence of disease activity (versus 7% on placebo) and 30% achieving sustained disability improvement (versus 19% on placebo). Natalizumab did not achieve a statistically significant primary composite disability outcome in a trial of 887 patients with secondary progressive MS, but it did demonstrate a benefit on a prespecified component of the 9-Hole Peg Test. The greatest risk of natalizumab treatment is progressive multifocal leukoencephalopathy (PML), with a 23% mortality rate. Risk stratification on the basis of immunosuppressant exposure, natalizumab treatment duration and anti-John Cunningham virus (JCV) antibody status and index has greatly improved clinical decision making. Other potential serious natalizumab-associated risks reported in clinical trials and postmarketing settings include infusion reactions, hepatotoxicity and rare, serious opportunistic infections. With more than a decade of continuous postmarketing experience, natalizumab remains a very effective option for patients with relapsing forms of MS. To optimize appropriate selection of natalizumab for patients with relapsing MS, however, a thorough understanding of individual patient risk factors for PML or other adverse events is also required.

Randomised natalizumab discontinuation study: taper protocol may prevent disease reactivation

OBJECTIVES

To compare two modes of natalizumab cessation interventions: immediate versus tapered down, as measured by serial MRI and the occurrence of relapses during a 12-month period.

BACKGROUND

Weighing progressive multifocal encephalopathy risk associated with ≥24 months of natalizumab therapy against the benefits of disease control, we initiated a natalizumab discontinuation study.

METHODS

A phase IV, 12-month, single-blinded randomised (MRI) study. Fifty relapsing patients with multiple sclerosis (MS) who had been on natalizumab therapy ≥24 months and were contemplating natalizumab discontinuation were enrolled. Participants were randomised to either the immediate discontinuation group (IDG) or the tapered group (TG). IDG discontinued natalizumab at once and initiated another disease modifying therapy (DMT) following the last natalizumab infusion, while the TG received two more natalizumab infusions, at 6 and 8 weeks (14 weeks from study entry) before initiating another DMT. Standardised MRI was performed at baseline, 6 and 12 months from the last natalizumab infusion.

RESULTS

A higher rate of relapses in the IDG (n=28) compared to the TG (n=8) over 12 months from the last infusion (p=0.007) was observed, most relapses occurred within 3 months of discontinuation (20 vs 7 relapses, p=0.012). The IDG showed a higher number of new T2 lesions within 6-12 months of discontinuation (p=0.025), a higher mean absolute T2-LV change from 0 to 12 months (1.1 vs 0.1 mL, p=0.024) and a higher number of new T1-hypointense lesions over 0-12 months (p=0.005) as well as from baseline to 6 months (p=0.026) compared to the TG.

CONCLUSIONS

Natalizumab discontinuation therapy was associated with development of new disease activity. Our tapered protocol showed benefits, as patients in the TG experienced less relapses and lower accumulation of MRI lesions compared to those in the IDG.

New insights into the pharmacokinetics and pharmacodynamics of natalizumab treatment for patients with multiple sclerosis, obtained from clinical and in vitro studies

BACKGROUND

The monoclonal antibody natalizumab (NAT) inhibits the migration of lymphocytes throughout the blood-brain barrier by blocking very late antigen (VLA)-4 interactions, thereby reducing inflammatory central nervous system (CNS) activity in patients with multiple sclerosis (MS). We evaluated the effects of different NAT treatment regimens.

METHODS

We developed and optimised a NAT assay to measure free NAT, cell-bound NAT and VLA-4 expression levels in blood and cerebrospinal fluid (CSF) of patients using standard and prolonged treatment intervals and after the cessation of therapy.

RESULTS

In paired CSF and blood samples of NAT-treated MS patients, NAT concentrations in CSF were approximately 100-fold lower than those in serum. Cell-bound NAT and mean VLA-4 expression levels in CSF were comparable with those in blood. After the cessation of therapy, the kinetics of free NAT, cell-bound NAT and VLA-4 expression levels differed. Prolonged intervals greater than 4 weeks between infusions caused a gradual reduction of free and cell-bound NAT concentrations. Sera from patients with and without NAT-neutralising antibodies could be identified in a blinded assessment. The NAT-neutralising antibodies removed NAT from the cell surface in vivo and in vitro. Intercellular NAT exchange was detected in vitro.

CONCLUSIONS

Incorporating assays to measure free and cell-bound NAT into clinical practice can help to determine the optimal individual NAT dosing regimen for patients with MS.

Natalizumab versus fingolimod in patients with relapsing-remitting multiple sclerosis non-responding to first-line injectable therapies

BACKGROUND

Natalizumab and fingolimod have not been compared in controlled trials but only in observational studies, with inconclusive results.

OBJECTIVES

The objective of this study is to compare the effect of natalizumab and fingolimod in reducing disease activity in relapsing-remitting multiple sclerosis (RRMS).

METHODS

We included all consecutive RRMS patients switched from first-line agents (glatiramer acetate/interferons) to natalizumab or fingolimod, with a follow-up of 24 months. Data of relapses, Expanded Disability Status Scale score and brain magnetic resonance imaging (MRI) scans were collected. We used propensity score (PS) matching and intention-to-treat analysis.

RESULTS

We retained 102 patients in each cohort after PS matching, with similar baseline characteristics. More patients discontinued natalizumab compared to fingolimod (33% vs 11%, p < 0.001), mainly for progressive multifocal leukoencephalopathy (PML) concern. No serious adverse events occurred in the two cohorts. Compared to fingolimod, the natalizumab group presented a higher percentage of relapse-free patients (66% vs 80%, p = 0.015), a higher percentage of disability-improved patients (6% vs 15%, p = 0.033), a lower percentage of MRI-active patients (38% vs 14%, p = 0.001) and a higher percentage of patients with no evidence of disease activity (NEDA-3; 44% vs 70%, p < 0.001) after 2 years of follow-up. Disability worsening was not statistically different in the two groups.

CONCLUSION

Natalizumab is superior to fingolimod in RRMS patients non-responding to first-line agents.

Comparative efficacy of first-line natalizumab vs IFN-β or glatiramer acetate in relapsing MS

BACKGROUND

We compared efficacy and treatment persistence in treatment-naive patients with relapsing-remitting multiple sclerosis (RRMS) initiating natalizumab compared with interferon-β (IFN-β)/glatiramer acetate (GA) therapies, using propensity score-matched cohorts from observational multiple sclerosis registries.

METHODS

The study population initiated IFN-β/GA in the MSBase Registry or natalizumab in the Tysabri Observational Program, had ≥3 months of on-treatment follow-up, and had active RRMS, defined as ≥1 gadolinium-enhancing lesion on cerebral MRI at baseline or ≥1 relapse within the 12 months prior to baseline. Baseline demographics and disease characteristics were balanced between propensity-matched groups. Annualized relapse rate (ARR), time to first relapse, treatment persistence, and disability outcomes were compared between matched treatment arms in the total population (n = 366/group) and subgroups with higher baseline disease activity.

RESULTS

First-line natalizumab was associated with a 68% relative reduction in ARR from a mean (SD) of 0.63 (0.92) on IFN-β/GA to 0.20 (0.63) (p [signed-rank] < 0.0001), a 64% reduction in the rate of first relapse (hazard ratio [HR] 0.36, 95% confidence interval [CI] 0.28-0.47; p < 0.001), and a 27% reduction in the rate of discontinuation (HR 0.73, 95% CI 0.58-0.93; p = 0.01), compared with first-line IFN-β/GA therapy. Confirmed disability progression and area under the Expanded Disability Status Scale-time curve analyses were not significant. Similar relapse and treatment persistence results were observed in each of the higher disease activity subgroups.

CONCLUSIONS

This study provides Class IV evidence that first-line natalizumab for RRMS improves relapse and treatment persistence outcomes compared to first-line IFN-β/GA. This needs to be balanced against the risk of progressive multifocal leukoencephalopathy in natalizumab-treated patients.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that first-line natalizumab for RRMS improves relapse rates and treatment persistence outcomes compared to first-line IFN-β/GA.

Dimethyl fumarate in the management of multiple sclerosis: appropriate patient selection and special considerations

Delayed-release dimethyl fumarate (DMF), also known as gastroresistant DMF, is the most recently approved oral disease-modifying treatment (DMT) for relapsing multiple sclerosis. Two randomized clinical trials (Determination of the Efficacy and Safety of Oral Fumarate in Relapsing-Remitting MS [DEFINE] and Comparator and an Oral Fumarate in Relapsing-Remitting Multiple Sclerosis [CONFIRM]) demonstrated significant efficacy in reducing relapse rate and radiological signs of disease activity, as seen on magnetic resonance imaging. The DEFINE study also indicated a significant effect of DMF on disability worsening, while the low incidence of confirmed disability worsening in the CONFIRM trial rendered an insignificant reduction among the DMF-treated groups when compared to placebo. DMF also demonstrated a good safety profile and acceptable tolerability, since the most common side effects (gastrointestinal events and flushing reactions) are usually transient and mild to moderate in severity. Here, we discuss the place in therapy of DMF for individuals with relapsing multiple sclerosis, providing a tentative therapeutic algorithm to manage newly diagnosed patients and those who do not adequately respond to self-injectable DMTs. Literature data supporting the potential role of DMF as a first-line therapy are presented. The possibility of using DMF as switching treatment or even as an add-on strategy in patients with breakthrough disease despite self-injectable DMTs will also be discussed. Lastly, we argue about the role of DMF as an exit strategy from natalizumab-treated patients who are considered at risk for developing multifocal progressive leukoencephalopathy.