Predictors of hematological abnormalities in multiple sclerosis patients treated with fingolimod and dimethyl fumarate and impact of treatment switch on lymphocyte and leukocyte count

Frequency of Dimethyl Fumarate-Induced Lymphopenia among Omani Patients with Multiple Sclerosis

Objectives

Dimethyl fumarate (DMF) is known to cause lymphopenia when used to treat patients with multiple sclerosis (MS). However, research on DMF therapy in the Arab world, especially in Oman, is scarce. This study aimed to analyse the prevalence of lymphopenia among Omani patients with MS and their reasons for discontinuing DMF therapy.

Methods

In this retrospective study, the medical records of Omani patients with MS who were treated using DMF at two tertiary hospitals in Muscat, Oman, from February 2017 to February 2023 were reviewed. Their demographic, clinical and laboratory data were retrieved and analysed. Absolute lymphocyte count values at baseline and at the last follow-up, as well as the reasons for discontinuing DMF therapy, were collected. Descriptive and inferential statistical techniques were used for data analysis. Binary-logistic regression analysis was used to identify the risk factors for DMF-induced lymphopenia.

Results

A total of 64 Omani patients with MS were included in this study. The majority of the study participants (n = 40; 63%) were female. All included patients started DMF therapy at the mean age of 33 ± 7.7 years. After administration of DMF, 14 (21.9%) patients developed grades 1-3 of lymphopenia. The DMF therapy was discontinued for 23 (36.0%) patients, mainly in response to adverse events or confirmed pregnancy. Female gender was the only significant predictor of DMF-induced lymphopenia (P = 0.037).

Conclusions

Most Omani patients with MS had mild lymphopenia (grades 1-2). Early adverse events and pregnancy were the main reasons provided for discontinuing DMF therapy.

Stroke risk in multiple sclerosis: a critical appraisal of the literature

Observational studies suggest that the occurrence of stroke on multiple sclerosis (MS) patients is higher compared to the general population. MS is a heterogeneous disease that involves an interplay of genetic, environmental and immune factors. The occurrence of stroke is subject to a wide range of both modifiable and non-modifiable, short- and long-term risk factors. Both MS and stroke share common risk factors. The immune mechanisms that underlie stroke are similar to neurodegenerative diseases and are attributed to neuroinflammation. The inflammation in autoimmune diseases may, therefore, predispose to an increased risk for stroke or potentiate the effect of conventional stroke risk factors. There are, however, additional determinants that contribute to a higher risk and incidence of stroke in MS. Due to the challenges that are associated with their differential diagnosis, the objective is to present an overview of the factors that may contribute to increased susceptibility or occurrence of stroke in MSpatients by performing a review of the available to date literature. As both MS and stroke can individually detrimentally affect the quality of life of afflicted patients, the identification of factors that contribute to an increased risk for stroke in MS is crucial for the prompt implementation of preventative therapeutic measures to limit the additive burden that stroke imposes.

Effectiveness and safety of switching to teriflunomide in older patients with relapsing multiple sclerosis: A real-world retrospective multicenter analysis

BACKGROUND

The prevalence of multiple sclerosis (MS) in older people is increasing due to population aging and availability of effective disease-modifying therapies (DMTs). Treating older people with MS is complicated by age-related and MS-related comorbidities, immunologic effects of prior DMTs, and immunosenescence. Teriflunomide is a once-daily oral immunomodulator that has demonstrated efficacy and acceptable safety in clinical trials of adults with relapsing forms of MS (RMS). However, there are limited clinical trial and real-world data regarding teriflunomide use in people with MS aged >55 years. We analyzed real-world data to assess the effectiveness and safety of teriflunomide in older people with RMS who had switched to this agent from other DMTs.

METHODS

People with RMS (relapsing remitting and active secondary progressive MS) aged ≥55 years who had switched from other DMTs to teriflunomide (7 mg or 14 mg) for ≥1 year were identified retrospectively by chart review at four sites in the United States. Data were extracted from medical records from 1 year pre-index to 2 years post-index (index defined as the teriflunomide start date). Assessments of effectiveness included annualized relapse rate (ARR), Expanded Disability Status Scale (EDSS) score, and magnetic resonance imaging (MRI) outcomes. Assessments of safety included lymphocyte counts, infections, and malignancies. We examined the effectiveness outcomes and lymphocyte counts within sub-groups defined by age (55-64, ≥65 years), sex, MS type, and prior route of DMT administration (oral, injectable, infusible).

RESULTS

In total, 182 patients with RMS aged ≥55 years who switched from other DMTs to teriflunomide were identified (mean [SD] age: 62.5 [5.4] years). Mean ARR decreased from the start of teriflunomide treatment (mean [SD]: 0.43 [0.61]) to year 1 post-index (0.13 [0.65]) and year 2 post-index (0.05 [0.28]). Mean EDSS score remained unchanged from index (mean [SD]: 4.5 [1.8]) to 1 year post-treatment (4.5 [1.8]) and increased slightly at 2 years post-treatment (4.7 [1.7]). MRI scans from index and years 1 and 2 post-index compared with scans from the previous year indicated that most patients had stable or improved MRI outcomes at index (87.7%) and remained stable or improved at years 1 (96.0%) and 2 (93.6%). Lymphopenia decreased at years 1 (21.4%) and 2 post-index (14.8%, compared to index (23.5%). By 1 year post-index, fewer patients had grade 3 or 4 lymphopenia, and at 2 years post-index, there were no patients with grade 3 or 4 lymphopenia. Infection incidence was low (n = 40, 22.0%) and none were related to teriflunomide. The decreases in lymphopenia were driven by decreases among people who switched from a prior oral DMT; there were no notable differences in lymphopenia across the other sub-groups examined. ARR, EDSS score, and MRI outcomes across all sub-groups were similar to the results of the overall population.

CONCLUSION

Our multicenter, longitudinal, retrospective study demonstrated that patients with RMS aged 55 or older switching to teriflunomide from other DMTs had significantly improved ARR, stable disability, and stable or improved MRI over up to 2 years' follow up. Safety results were acceptable with fewer patients exhibiting lymphopenia at years 1 and 2 post-index.

Sex and gender differences in autoimmune demyelinating CNS disorders: Multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD) and myelin-oligodendrocyte-glycoprotein antibody associated disorder (MOGAD)

Multiple sclerosis (MS), Neuromyelitis optica spectrum disorder (NMOSD) and Myelin-Oligodendrocyte-Glycoprotein antibody associated disorder (MOGAD) are demyelinating disorders of the central nervous system (CNS) of autoimmune origin. Here, we summarize general considerations on sex-specific differences in the immunopathogenesis and hormonal influences as well as key clinical and epidemiological elements. Gender-specific issues are widely neglected starting with the lacking separation of sex as a biological variable and gender comprising the sociocultural components. As for other autoimmune diseases, female preponderance is common in MS and NMOSD. However, sex distribution in MOGAD seems equal. As in MS, immunotherapy in NMOSD and MOGAD is crucial to prevent further disease activity. Therefore, we assessed data on sex differences of the currently licensed disease-modifying treatments for efficacy and safety. This topic seems widely neglected with only fragmented information resulting from post-hoc analyses of clinical trials or real-world post-marketing studies afflicted with lacking power and/or inherent sources of bias. In summary, biological hypotheses of sex differences including genetic factors, the constitution of the immune system and hormonal influences are based upon human and preclinical data, especially for the paradigmatic disease of MS whereas specific data for NMOSD and MOGAD are widely lacking. Epidemiological and clinical differences between men and women are well described for MS and to some extent for NMOSD, yet, with remaining contradictory findings. MOGAD needs further detailed investigation. Sex-specific analyses of safety and efficacy of long-term immunotherapies need to be addressed in future studies designed and powered to answer the pressing questions and to optimize and individualize treatment.

Predictors of lymphocyte count recovery after dimethyl fumarate-induced lymphopenia in people with multiple sclerosis

BACKGROUND

Dimethyl fumarate (DMF) is an oral drug approved for Relapsing Multiple Sclerosis (RMS) patients. Grade III lymphopenia is reported in 5-10% DMF-treated patients. Data on lymphocyte count (ALC) recovery after DMF withdrawal following prolonged lymphopenia are still scarce.

OBJECTIVES

To characterize ALC recovery and to identify predictors of slower recovery after DMF interruption.

METHODS

Multicenter data from RMS patients who started DMF and developed lymphopenia during treatment were collected. In patients with grade II-III lymphopenia, ALCs were evaluated from DMF withdrawal until reaching lymphocyte counts > 800/mm³.

RESULTS

Among 1034 patients who started DMF, we found 198 (19.1%) patients with lymphopenia and 65 patients (6.3%) who discontinued DMF due to persistent grade II-III lymphopenia. Complete data were available for 51 patients. All patients recovered to ALC > 800 cells/mm³ with a median time of 3.4 months. Lower ALCs at DMF suspension (HR 0.98; p = 0.005), longer disease duration (HR 1.29; p = 0.014) and prior exposure to MS treatments (HR 0.03; p = 0.025) were found predictive of delayed ALC recovery.

CONCLUSION

ALC recovery after DMF withdrawal is usually rapid, nevertheless it may require longer time in patients with lower ALC count at DMF interruption, longer disease duration and previous exposure to MS treatments, potentially leading to delayed initiation of a new therapy.

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 lymphopenia in multiple sclerosis: A review of the literature

Dimethyl fumarate (DMF) is a first line medication for multiple sclerosis. It has a favourable safety profile, however, there is concern regarding the occurrence of moderate-severe and sustained lymphopenia and the associated risk of progressive multifocal leukoencephalopathy. We carried out an extensive literature review to understand the molecular mechanisms underlying this adverse reaction. Dynamic changes in certain components of the immune system are likely to be important for the therapeutic effects of DMF, including depletion of memory T cells and decrease in activated T cells together with expansion of naïve T cells. Similar modifications were reported for the B cell components. CD8⁺ T cells are particularly susceptible to DMF-induced cell death, with marked reductions observed in lymphopenic subjects. The reasons underlying such increased sensitivity are not known, nor it is known how expansion of other lymphocyte subsets occurs. Understanding the molecular mechanisms underlying DMF action is challenging: in vivo DMF is rapidly metabolized to monomethyl fumarate (MMF), a less potent immunomodulator in vitro. Pharmacokinetics indicate that MMF is the main active species in vivo. However, the relative importance of DMF and MMF in toxicity remains unclear, with evidence presented in favour of either of the compounds as toxic species. Pharmacogenetic studies to identify genetic predictors of DMF-induced lymphopenia are limited, with inconclusive results. A role of the gut microbiome in the pharmacological effects of DMF is emerging. It is clear that further investigations are necessary to understand the mechanisms of DMF-induced lymphopenia and devise preventive strategies. Periodic monitoring of absolute lymphocyte counts, currently performed in clinical practise, allows for the early detection of lymphopenia as a risk-minimization strategy.

Hematological Alterations Related to Treatment with Teriflunomide and Dimethyl Fumarate in Multiple Sclerosis

The exact mechanism of action of different modifying treatments in the evolutionary course of multiple sclerosis (MS) remains unknown, but it is assumed that they act upon the cells involved in acquired immunity. One effect of these treatments is the development of lymphopenia, which carries inherent safety risks. This study was conducted to understand the alterations that teriflunomide (TERI) and dimethyl fumarate (DMF) exert upon white blood cells in a series of patients with MS. This study included a total of 99 patients; 44 treated with DMF and 55 patients treated with TERI. Blood counts were evaluated at baseline and every 6 months in order to track the absolute leukocyte, lymphocyte, and neutrophil counts. Twelve months after starting treatment, we observed a significant decrease in leukocytes (21.1%), lymphocytes (39.1%), and neutrophils (10%) in the DMF group. In the TERI group, leukocytes decreased by 11.1%, lymphocytes by 8.1%, and neutrophils by 15.7%. Both TERI and DMF produced a significant decrease in leukocytes during the first year of treatment and this was mainly related with a decrease in neutrophils in the TERI group and a decrease in lymphocytes in the DMF group.

Dimethyl Fumarate: A Review in Relapsing-Remitting MS

Dimethyl fumarate (Tecfidera^®) is approved for the treatment of relapsing forms of multiple sclerosis (MS). Based on evidence from the clinical trial and real-world settings, dimethyl fumarate is an effective treatment in this patient population, with benefits maintained over the longer term. In the pivotal, placebo-controlled phase III DEFINE and CONFIRM trials in adults with relapsing-remitting multiple sclerosis (RRMS), twice-daily dimethyl fumarate reduced clinical relapse and MRI measures of disease activity and improved some aspects of health-related quality of life (HR-QoL). Reduced disability progression was also observed with dimethyl fumarate in DEFINE. Results in predominantly East Asian patients (APEX trial) were reflective of those seen in DEFINE and CONFIRM. Dimethyl fumarate had an acceptable tolerability profile. The most common adverse events were flushing and gastrointestinal events, which were of mild or moderate severity and appear to be largely manageable. Thus twice-daily dimethyl fumarate remains an effective treatment option for use in patients with RRMS, with the convenience of oral administration.

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.

Hidden relationship between fingolimod and bleeding: Possible novel management of fingolimod-associated lymphopenia

Fingolimod, a functional antagonist of sphingosine-1 phosphate receptor, is a disease modifying drug of multiple sclerosis and its remarkable adverse effect is peripheral lymphopenia because the drug retains lymphocyte in the secondary lymphoid tissues. Therefore, in theory, when severe bleedings occurred, the fingolimod-treated patients could not compensate for the loss of lymphocytes induced by bleedings because of the retention in the secondary lymphoid tissues. In addition, because most of the fingolimod is reported to be distributed in the erythrocytes, and the erythrocytes are the main regulator of serum sphingosine-1 phosphate concentration, bleeding may also affect metabolism of fingolimod and prognosis of multiple sclerosis. However, no study had focused the relationship between fingolimod and bleedings in multiple sclerosis. We encountered the first case in which fingolimod-associated lymphopenia worsened synchronously with gynecological bleeding, and was improved by the bleeding prophylaxis, uterine myomectomy. This case had statistically significant positive correlation between the serum hemoglobin level and peripheral lymphocyte count (P = 0.0000000507). We then had three similar cases. In these 4 correlative patients out of the 14 fingolimod-treated patients in our institution, the importance of the bleeding in fingolimod-treated patients was indicated by line graphs, point diagrams, and statistically significant correlation coefficients. Bleeding should be focused on by all of physicians treating multiple sclerosis with fingolimod.

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.

Clinical evaluation of dimethyl fumarate for the treatment of relapsing-remitting multiple sclerosis: efficacy, safety, patient experience and adherence

Dimethyl fumarate (DMF) is an oral disease-modifying therapy approved for management of relapsing-remitting multiple sclerosis patients. Results from phase 3 clinical trials (DEFINE, CONFIRM) and follow-up study (ENDORSE) have provided good evidence for its efficacy and safety profile. Patient-reported outcomes (PROs) assessment revealed stabilization or boost in health-related quality of life and work productivity of patients treated with DMF compared to placebo reflecting a higher patient satisfaction to therapy. Being an oral agent with relatively favorable risk versus benefit profile DMF is commonly prescribed first-line agent. However, literature suggests that intolerance to side effects, especially gastrointestinal adverse effects and flushing is one of the major causes to compromised therapeutic compliance. An increase in the real-world incidence of progressive multifocal leukoencephalopathy and liver abnormality cases is also concerning. Several prevention and mitigation strategies like patient counseling, dose up-titration, pretreatment with aspirin, use of symptomatic therapy and frequent blood monitoring have demonstrated to be effective in tackling these adverse effects and promoting adherence to DMF. In this article, we review the efficacy, safety, PROs and patient adhere data, along with various measures to manage adverse events and promote compliance.

Safety and Efficacy of Dimethyl Fumarate in Multiple Sclerosis: An Italian, Multicenter, Real-World Study

BACKGROUND

Two phase III trials have demonstrated the clinical and radiological efficacy of delayed-release dimethyl fumarate (DMF) in relapsing-remitting multiple sclerosis (RRMS). However, data on its safety and effectiveness in real-world practice are still limited.

OBJECTIVES

The aim of our study was to explore the safety and tolerability profile of DMF in RRMS. We also tried to identify individual variables associated with better clinical and radiological outcomes.

METHODS

We collected the clinical and magnetic resonance imaging (MRI) data of patients with RRMS who started DMF between 2012 and 2017 in seven MS clinics in central Italy. We first evaluated DMF discontinuation rates and the incidence of adverse events and side effects. We then assessed the annualized relapse rate (ARR), the number of patients with clinical relapses or disability worsening and the presence of radiological activity. Third, we investigated which baseline variables were associated with clinical and radiological outcomes.

RESULTS

We collected data for 1089 patients with a mean on-treatment follow-up of 17 ± 8 months; 331 (30.4%) of these patients were treatment naïve. In total, 210 (19.5%) patients discontinued DMF mainly because of poor tolerability (n = 103) and disease activity (n = 63), and 166 (16.5%) patients presented with lymphopenia. The ARR reduced from 0.55 to 0.13. Mean change in Expanded Disability Status Scale (EDSS) score was 0.08 ± 0.44 per year. The occurrence of clinical and/or radiological activity during follow-up was associated with younger age [hazard ratio (HR) 0.97; p < 0.001], higher EDSS score (HR 1.18; p < 0.001), greater number of Gd-enhancing lesions at baseline scan (HR 1.14; p = 0.003) and prior exposure to MS treatments (HR 1.43; p = 0.02).

CONCLUSION

This post-marketing data confirms the short-term safety, tolerability and effectiveness of DMF, supporting its use as an early treatment in MS.