Lymphocyte Count and Body Mass Index as Biomarkers of Early Treatment Response in a Multiple Sclerosis Dimethyl Fumarate-Treated Cohort

Clinical use of dimethyl fumarate in multiple sclerosis treatment: an update to include China, using a modified Delphi method

Dimethyl fumarate (DMF) is a widely used oral disease-modifying therapy for multiple sclerosis (MS). Its efficacy and safety profiles are supported by over a decade of experience. Differences exist between Asia and Europe/United States in the prevalence and characteristics of MS; most data for DMF are derived from populations outside Asia. DMF was recently (2021) approved for use in China. The objectives of this review were to evaluate the evidence for DMF's profile, to provide an update to healthcare providers on current knowledge surrounding its use and to assess the relevance of existing data to use in China. This study used a modified Delphi method based on the insights of a scientific Steering Committee (SC), with a structured literature review conducted to assess the data of DMF. The literature review covered all papers in English (from 01 January 2011 to 21 February 2022) that include 'dimethyl fumarate' and 'multiple sclerosis', and their MeSH terms, on PubMed, supplemented by EMBASE and Citeline searches. Papers were categorized by topic and assessed for relevance and quality, before being used to formulate statements summarizing the literature on each subject. SC members voted on/revised statements, requiring ⩾80% agreement and ⩽10% disagreement for inclusion. Statements not reaching this level were discussed further until agreement was reached or until there was agreement to remove the statement. A total of 1030 papers were retrieved and used to formulate the statements and evidence summaries considered by the SC members. A total of 45 statements were agreed by the SC members. The findings support the positive efficacy and safety profile of DMF in treating patients with MS. Limited Chinese patient data are an ongoing consideration; however, based on current evidence, the statements are considered applicable to both the global and Chinese populations. DMF is a valuable addition to address unmet MS treatment needs in China. Registration: Not applicable.

Lymphopenia during treatment with dimethyl fumarate in patients with multiple sclerosis: Prevalence, predicting factors and clinical outcomes

BACKGROUND

Lymphopenia is a common side effect of treatment with dimethyl fumarate (DMF) in patients with multiple sclerosis (PwMS). Prevalence and predictive factors of this side effect are still uncertain, because literature has provided discrepant results and it is still a matter of debate if lymphopenia is associated with a better treatment outcome.

METHODS

We retrospectively recruited PwMS treated for at least one month with DMF and collected clinical, demographic data and absolute lymphocyte count (ALC) during follow-up. Lymphopenia was graded according to CTCAE. Patients according to the grade in lymphopenia (all grades) and severe lymphopenia (grade II-IV). To evaluate predictors of lymphopenia, we compared characteristics of patients with/without lymphopenia and patients with/without severe lymphopenia. A logistic binary regression was performed to elucidate any predictive factor of lymphopenia and severe lymphopenia. Area under the curve (AUC) was calculated to evaluate sensibility and specificity of predictors. We analyzed treatment outcome with NEDA-3 status at 1- and 2-years.

RESULTS

98 of 105 patients treated with DMF were included. 46.9% developed lymphopenia, 27.6% severe lymphopenia. Lymphopenia was associated with basal ALC (p<0.001, AUC=0.786), treatment duration (p = 0.01, AUC=0.685),% of reduction at third month (p = 0.001, AUC=0.616) Severe lymphopenia was associated with basal ALC (p = 0.003, AUC=0.750).NEDA-3 status at 1-year (n = 66) and at 2-year (n = 44) did not differ in patients with/without lymphopenia (p = 0.059; p = 0.583) or with/without severe lymphopenia (p = 1.02; p = 0.169).

CONCLUSION

Lymphopenia is a common side effect of DMF and basal ALC predicts its development. Lymphopenia is not associated with the achievement of NEDA-3 status.

Dimethyl fumarate treatment restrains the antioxidative capacity of T cells to control autoimmunity

Dimethyl fumarate, an approved treatment for relapsing-remitting multiple sclerosis, exerts pleiotropic effects on immune cells as well as CNS resident cells.

Here, we show that dimethyl fumarate exerts a profound alteration of the metabolic profile of human CD4⁺ as well as CD8⁺ T cells and restricts their antioxidative capacities by decreasing intracellular levels of the reactive oxygen species scavenger glutathione. This causes an increase in mitochondrial reactive oxygen species levels accompanied by an enhanced mitochondrial stress response, ultimately leading to impaired mitochondrial function. Enhanced mitochondrial reactive oxygen species levels not only result in enhanced T-cell apoptosis in vitro as well as in dimethyl fumarate-treated patients, but are key for the well-known immunomodulatory effects of dimethyl fumarate both in vitro and in an animal model of multiple sclerosis, i.e. experimental autoimmune encephalomyelitis. Indeed, dimethyl fumarate immune-modulatory effects on T cells were completely abrogated by pharmacological interference of mitochondrial reactive oxygen species production.

These data shed new light on dimethyl fumarate as bona fide immune-metabolic drug that targets the intracellular stress response in activated T cells, thereby restricting mitochondrial function and energetic capacity, providing novel insight into the role of oxidative stress in modulating cellular immune responses and T cell-mediated autoimmunity.

Ocrelizumab depletes T-lymphocytes more than rituximab in multiple sclerosis

BACKGROUND

We aim to directly compare changes in lymphocyte subpopulations between chimeric (rituximab) and humanised (ocrelizumab) anti-CD20 antibodies in multiple sclerosis (MS).

METHODS

In this retrospective analysis of prospectively collected data, we included 88 patients with MS, treated with rituximab (n=50) or ocrelizumab (n=38). We used flow cytometry in the peripheral blood to count total lymphocytes and lymphocytes expressing different phenotypic markers (CD4, CD8, CD19, CD20, CD4/CD8 ratio), before treatment and after 1, 3 and 6 months.

RESULTS

On linear mixed effect regression models, after 1, 3 and 6 months, patients treated with rituximab and with ocrelizumab were similar in total lymphocyte count, CD19 lymphocytes, CD20 lymphocytes and CD4/CD8 ratio. However, patients treated with ocrelizumab presented with lower CD4 T lymphocytes and CD8 T lymphocytes after 1, 3 and 6 months (all p<0.05). No between-treatment difference in EDSS progression was found.

DISCUSSION

B-cell levels in the peripheral blood were equally decreased by rituximab and ocrelizumab. On the contrary, CD4 and CD8 T lymphocyte reduction was more pronounced in ocrelizumab, when compared with rituximab, suggesting a broader immunomodulatory effect for the humanised antibody to be confirmed and correlated with clinical efficacy in the long term.

Lower lymphocyte counts and older age are associated with reduced multiple sclerosis disease activity during dimethyl fumarate treatment

BACKGROUND

delayed-release dimethyl fumarate (DMF) is a disease modifying therapy for relapsing-remitting multiple sclerosis (MS) with antioxidant and anti-inflammatory properties. The drug causes lymphocyte count reduction, which can lead to lymphopenia development during treatment. This is an important safety issue, due to infectious risk, mainly progressive multifocal leukoencephalopathy (PML). If the lymphocyte count influences the response to treatment is still a matter of debate, as there are contrasting contrasting data in the literature. Considering this, we aimed to identify DMF induced lymphopenia risk factors and to evaluate lymphopenia impact on MS disease activity in a real world setting.

METHODS

a retrospective study on 135 MS patients receiving DMF with a mean treatment duration of 32.3±15.9 months was performed. Baseline and follow-up demographic, clinical, magnetic resonance imaging (MRI) and laboratory data were collected.

RESULTS

44 patients (32.6%) developed lymphopenia, with 11 (8.1%) grade 1, 23 (17.0%) grade 2 and 10 (7.4 %) grade 3. Older age and lower basal absolute lymphocyte count were found to be associated with lymphopenia development on a binary regression model (p<0.001 and p=0.009). When compared with non lymphopenic+lymphopenia grade 1 patients, those experiencing lymphopenia grade 2+3 had longer disease activity free survival (p<0.001), fewer clinical relapses (p=0.005) and lower MRI disease activity (p≤0.001). On Cox regression model, older age and lymphopenia grade 2+3 were found to be protective factors against disease activity (HR=0.966; 95% C.I.=0.942-0.992; p=0.009 for age; HR=0.137; 95% C.I.=0.043-0.439; p=0.001 for lymphopenia grade 2+3) and MRI disease activity (HR=0.968; 95% C.I.=0.941-0.997; p=0.030 for age; HR=0.142; 95% C.I.=0.034-0.591; p=0.007 for lymphopenia grade 2+3). Only lymphopenia grade 2+3 was found to be a predictor of clinical relapses (HR=0.970; 95% C.I.=0.936-1.005; p=0.095 for age; HR=0.115; 95% C.I.=0.016-0.854; p=0.034 for lymphopenia grade 2+3), with a protective effect.

CONCLUSION

older age and lower basal lymphocyte count were found to be associated with lymphopenia development. Lymphopenia grade 2+3 and older age could be protective against clinical and radiologic disease activity during DMF treatment.

Dimethyl fumarate-induced lymphocyte count drop is related to clinical effectiveness in relapsing-remitting multiple sclerosis

BACKGROUND AND PURPOSE

Dimethyl fumarate (DMF) causes a mean lymphocyte count drop of approximately 30% in relapsing-remitting multiple sclerosis (RRMS) patients. The relationship between this reduction and DMF effectiveness is controversial. The objective was to investigate if the decrease in absolute lymphocyte count (ALC) from baseline during DMF treatment is associated with clinical and magnetic resonance imaging (MRI) disease activity. A secondary aim was to evaluate ALC variations over time in a real-life cohort of DMF-treated patients.

METHODS

Demographic, laboratory, clinical and MRI data were collected in this observational multicentre study, conducted on RRMS patients treated with DMF for at least 6 months. Multivariate Cox models were performed to evaluate the impact of 6-month ALC drop on time to no evidence of disease activity (NEDA-3) status loss. NEDA-3 is defined as absence of clinical relapses, MRI disease activity and confirmed disability progression.

RESULTS

In all, 476 patients (312 females, age at DMF start 38.4 ± 9.97 years) were analysed up to 5-year follow-up. A greater lymphocyte decrease was associated with a lower risk of NEDA-3 status loss (hazard ratio 0.87, P = 0.01). A worse outcome in patients with lower ALC drop (<11.5%), compared with higher tertiles (11.5%-40.5% and >40.5%), was observed (P = 0.008). The nadir of ALC drop (-33.6%) and 35% of grade III lymphopaenia cases occurred after 12 months of treatment.

CONCLUSION

A higher lymphocyte count drop at 6 months is related to better outcomes in DMF-treated patients. A careful ALC monitoring should be pursued up to 24 months of treatment.

Harmonization of real-world studies in multiple sclerosis: Retrospective analysis from the rirems group

BACKGROUND

Worldwide multiple sclerosis (MS) centers have coordinated their efforts to use data acquired in clinical practice for real-world observational studies. In this retrospective study, we aim to harmonize outcome measures, and to evaluate their heterogeneity within the Rising Italian Researchers in MS (RIReMS) study group.

METHODS

RIReMS members filled in a structured questionnaire evaluating the use of different outcome measures in clinical practice. Thereafter, thirty-four already-published papers from RIReMS centers were used for heterogeneity analyses, using the DerSimonian and Laird random-effects method to compute the between-study variance (τ²).

RESULTS

Based on questionnaire results, we defined basic modules for diagnosis and follow-up, consisting of outcome measures recorded by all participating centers at the time of diagnosis, and, then, at least annually; we also defined more detailed/optional modules, with outcome measures recorded less frequently and/or in the presence of specific clinical indications. Looking at heterogeneity, we found 5-year variance in age at onset (ES=27.34; 95%CI=26.18, 28.49; p<0.01; τ²=4.76), and 7% in female percent (ES=66.42; 95%CI=63.08, 69.76; p<0.01; τ²=7.15). EDSS variance was 0.2 in studies including patients with average age <36.1 years (ES=1.96; 95%CI=1.69, 2.24; p<0.01; τ²=0.19), or from 36.8 to 41.1 years (ES=2.70; 95%CI=2.39, 3.01; p<0.01; τ²=0.18), but increased to 3 in studies including patients aged >41.4 years (ES=4.37; 95%CI=3.40, 5.35; p<0.01; τ²=2.96). The lowest variance of relapse rate was found in studies with follow-up duration ≤2 years (ES=9.07; 95%CI=5.21, 12.93; p = 0.02; τ²=5.53), whilst the lowest variance in EDSS progression was found in studies with follow-up duration >2 years (ES=5.41; 95%CI=3.22, 7.60; p = 0.02; τ²=1.00).

DISCUSSION

We suggest common sets of biomarkers to be acquired in clinical practice, that can be used for research purposes. Also, we provide researchers with specific indications for improving inclusion criteria and data analysis, ultimately allowing data harmonization and high-quality collaborative studies.

Fingolimod and Dimethyl-Fumarate-Derived Lymphopenia is not Associated with Short-Term Treatment Response and Risk of Infections in a Real-Life MS Population

BACKGROUND

The association between treatment-related lymphopenia in multiple sclerosis, drug efficacy and the risk of infections is not yet fully understood.

OBJECTIVE

The objective of this study was to assess whether lymphopenia is associated with short-term treatment response and infection rate in a real-life multiple sclerosis population treated with fingolimod and dimethyl-fumarate. We assessed the associations between baseline absolute lymphocyte count and the lymphocyte mean percentage decrease at 6 and 12 months with treatment response and the occurrence of adverse events over 12 months in the entire cohort of patients and in the two treatment groups separately.

METHODS

This is a retrospective observational real-world study of patients with multiple sclerosis treated with fingolimod and dimethyl-fumarate at the MS Center of the University of Genoa between 2011 and 2018. Patients with at least 12 months of follow-up were eligible if [1] they had an Expanded Disability Status Scale assessment at baseline and 12 months after treatment onset, [2] they had undergone brain magnetic resonance imaging at baseline and after 12 months, and [3] absolute lymphocyte counts were available at baseline, 6 and 12 months. Patients shifting from dimethyl-fumarate to fingolimod or vice versa were excluded from the analysis.

RESULTS

In total, 137 and 75 patients treated with fingolimod and dimethyl-fumarate, respectively, were included in the analysis. At 12 months, fingolimod-treated patients were more likely to experience grade II and grade III lymphopenia compared with dimethyl-fumarate patients (p < 0.001, χ2 = 94) and had a higher lymphocyte mean percentage decrease (p < 0.001, U = 540). A higher number of previous therapies and a lower baseline absolute lymphocyte count were predictors of lymphopenia at 6 months (p = 0.047, odds ratio = 1.60 and p = 0.014, odds ratio = 1.1) and 12 months (p = 0.003, odds ratio = 1.97 and p = 0.023, odds ratio = 1.1). In fingolimod-treated patients only, female sex and a higher Expanded Disability Status Scale score were predictors of lymphopenia at 12 months (p = 0.006, odds ratio = 7.58 and p = 0.03, odds ratio = 1.56). Neither absolute lymphocyte count at 6 and 12 months nor the mean percentage decrease at 6 and 12 months predicted No Evidence of Disease Activity (NEDA-3) status at 1 year, the occurrence of relapses, disease activity on MRI or disability progression.

CONCLUSIONS

Our findings suggest that peripheral blood lymphocyte changes are not associated with short-term treatment response and with the rate of infections during fingolimod and dimethyl-fumarate treatment in real-world patients. Higher treatment exposure and a lower baseline absolute lymphocyte count are risk factors for lymphopenia development during fingolimod and dimethyl-fumarate therapy.

Efficacy and Safety of Oral Therapies for Relapsing-Remitting Multiple Sclerosis

Disease-modifying therapies have now become standard treatment for multiple sclerosis. These include five oral therapies for relapsing-remitting multiple sclerosis, namely fingolimod, dimethyl fumarate, teriflunomide, cladribine, and siponimod, although there is some discrepancy on the relative efficacy and safety of these agents. To gain further insight on these oral agents in relapsing-remitting multiple sclerosis, we performed a narrative review of fingolimod, dimethyl fumarate, teriflunomide, cladribine, and siponimod. We limited the analysis to randomized clinical studies in which a comparator was used (i.e., placebo or other disease-modifying therapy). As relapsing-remitting multiple sclerosis is a chronic disease and treatment is lifelong, long-term outcomes were an additional focus. A total of 37 studies met inclusion criteria: 15 for fingolimod, 8 for dimethyl fumarate, 7 for teriflunomide, 4 for cladribine, and 3 for siponimod. All drugs showed some functional and magnetic resonance imaging benefit in nearly all clinical studies. The reduction in annual relapse rate was similar for fingolimod, dimethyl fumarate, and cladribine, and somewhat greater than for teriflunomide; there is limited information on the annual relapse rate for siponimod. For all drugs, the benefits reported at short follow-up times are broadly consistent with those seen at longer follow-up times. For fingolimod and dimethyl fumarate, there was a definite trend towards a progressively lower annual relapse rate with continuing treatment. The safety profile of all five drugs was considered to be acceptable, even after extended treatment. While these results should be treated with caution, they highlight that future head-to-head studies are needed to better understand the long-term benefits of disease-modifying therapies. Such information will be of value when considering the risk-benefit profile of these oral therapies.