Safety and efficacy of rituximab as first- and second line treatment in multiple sclerosis - A cohort study

Hypogammaglobulinaemia during rituximab treatment in multiple sclerosis: A Swedish cohort study

BACKGROUND AND PURPOSE

Mechanisms behind hypogammaglobulinaemia during rituximab treatment are poorly understood.

METHODS

In this register-based multi-centre retrospective cohort study of multiple sclerosis (MS) patients in Sweden, 2745 patients from six participating Swedish MS centres were identified via the Swedish MS registry and included between 14 March 2008 and 25 January 2021. The exposure was treatment with at least one dose of rituximab for MS or clinically isolated syndrome, including data on treatment duration and doses. The degree of yearly decrease in immunoglobulin G (IgG) and immunoglobulin M (IgM) levels was evaluated.

RESULTS

The mean decrease in IgG was 0.27 (95% confidence interval 0.17-0.36) g/L per year on rituximab treatment, slightly less in older patients, and without significant difference between sexes. IgG or IgM below the lower limit of normal (<6.7 or <0.27 g/L) was observed in 8.8% and 8.3% of patients, respectively, as nadir measurements. Six out of 2745 patients (0.2%) developed severe hypogammaglobulinaemia (IgG below 4.0 g/L) during the study period. Time on rituximab and accumulated dose were the main predictors for IgG decrease. Previous treatment with fingolimod and natalizumab, but not teriflunomide, dimethyl fumarate, interferons or glatiramer acetate, were significantly associated with lower baseline IgG levels by 0.80-1.03 g/L, compared with treatment-naïve patients. Switching from dimethyl fumarate or interferons was associated with an additional IgG decline of 0.14-0.19 g/L per year, compared to untreated.

CONCLUSIONS

Accumulated dose and time on rituximab treatment are associated with a modest but significant decline in immunoglobulin levels. Previous MS therapies may influence additional IgG decline.

Immunopathogenesis of multiple sclerosis: molecular and cellular mechanisms and new immunotherapeutic approaches

Background: Multiple sclerosis (MS) is a central nervous system (CNS) demyelinating autoimmune disease with increasing global prevalence. It predominantly affects females, especially those of European descent. The interplay between environmental factors and genetic predisposition plays a crucial role in MS etiopathogenesis.

Methods: We searched recent relevant literature on reputable databases, which include, PubMed, Embase, Web of Science, Scopus, and ScienceDirect using the following keywords: multiple sclerosis, pathogenesis, autoimmunity, demyelination, therapy, and immunotherapy.

Results: Various animal models have been employed to investigate the MS etiopathogenesis and therapeutics. Autoreactive T cells within the CNS recruit myeloid cells through chemokine expression, leading to the secretion of inflammatory cytokines driving the MS pathogenesis, resulting in demyelination, gliosis, and axonal loss. Key players include T cell lymphocytes (CD4+ and CD8+), B cells, and neutrophils. Signaling dysregulation in inflammatory pathways and the immunogenetic basis of MS are essential considerations for any successful therapy to MS. Data indicates that B cells and neutrophils also have significant roles in MS, despite the common belief that T cells are essential. High neutrophil-to-lymphocyte ratios correlate with MS severity, indicating their contribution to disease progression. Dysregulated signaling pathways further exacerbate MS progression.

Conclusion: MS remains incurable, but disease-modifying therapies, monoclonal antibodies, and immunomodulatory drugs offer hope for patients. Research on the immunogenetics and immunoregulatory functions of gut microbiota is continuing to provide light on possible treatment avenues. Understanding the complex interplay between genetic predisposition, environmental factors, and immune dysregulation is critical for developing effective treatments for MS.

Hypogammaglobulinemia and infections in patients with multiple sclerosis treated with anti-CD20 treatments: a systematic review and meta-analysis of 19,139 multiple sclerosis patients

Background

Recent years have seen the emergence of disease-modifying therapies in multiple sclerosis (MS), such as anti-cluster of differentiation 20 (anti-CD20) monoclonal antibodies, aiming to modulate the immune response and effectively manage MS. However, the relationship between anti-CD20 treatments and immunoglobulin G (IgG) levels, particularly the development of hypogammaglobulinemia and subsequent infection risks, remains a subject of scientific interest and variability. We aimed to investigate the intricate connection between anti-CD20 MS treatments, changes in IgG levels, and the associated risk of hypogammaglobulinemia and subsequent infections.

Method

PubMed, Scopus, Embase, Cochrane, and Web of Science databases have been searched for relevant studies. The "R" software utilized to analyze the occurrence of hypogammaglobulinemia, infections and mean differences in IgG levels pre- and post-treatment. The subgrouping analyses were done based on drug type and treatment duration. The assessment of heterogeneity utilized the I2 and chi-squared tests, applying the random effect model.

Results

Thirty-nine articles fulfilled our inclusion criteria and were included in our review which included a total of 20,501 MS patients. The overall prevalence rate of hypogammaglobulinemia was found to be 11% (95% CI: 0.08 to 0.15). Subgroup analysis based on drug type revealed varying prevalence rates, with rituximab showing the highest at 18%. Subgroup analysis based on drug usage duration revealed that the highest proportion of hypogammaglobulinemia occurred in individuals taking the drugs for 1 year or less (19%). The prevalence of infections in MS patients with a focus on different infection types stratified by the MS drug used revealed that pulmonary infections were the most prevalent (9%) followed by urinary tract infections (6%), gastrointestinal infections (2%), and skin and mucous membrane infections (2%). Additionally, a significant decrease in mean IgG levels after treatment compared to before treatment, with a mean difference of 0.57 (95% CI: 0.22 to 0.93).

Conclusion

This study provides a comprehensive analysis of the impact of anti-CD20 drugs on serum IgG levels in MS patients, exploring the prevalence of hypogammaglobulinemia, based on different drug types, treatment durations, and infection patterns. The identified rates and patterns offer a foundation for clinicians to consider in their risk-benefit.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=518239, CRD42024518239.

Efficacy and safety of rituximab in multiple sclerosis and neuromyelitis optica spectrum disorder

In Thailand, resource limitations lead many multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) patients to use off-label immunosuppressants. This study assesses the efficacy and safety of rituximab (RTX) with a CD19-based reinfusion regimen among Thai MS and NMOSD patients. A retrospective review of patients at the Faculty of Medicine Siriraj Hospital from January 1994 to April 2023 was conducted. The primary outcome assessed was the change in annualized relapse rate (ARR) for patients using RTX for over a year. Secondary outcomes included changes in the Expanded Disability Status Scale (EDSS) scores, time to the first relapse after RTX initiation for patients using RTX for over a year, and an evaluation of the safety of RTX. The study encompassed 36 MS and 39 NMOSD patients. A majority of patients (91.7% of MS and 79.5% of NMOSD) experienced no relapses during a median follow-up of 30 months (Interquartile range [IQR] 20-46) and 31 months (IQR 23-41), respectively. The median ARR significantly decreased in both MS (from 0.77 [IQR 0.42-1.83] to 0 [IQR 0-0], p < 0.001) and NMOSD (from 0.92 [IQR 0.68-1.78] to 0 [IQR 0-0.17], p < 0.001) patients after switching to RTX, with no difference between those following a fixed 6-month time point regimen and a CD19-based reinfusion regimen. Median EDSS scores improved significantly at the last follow-up visit in both groups. The mean time to the first subsequent relapse was 8.3 ± 3.0 months in MS and 6.8 ± 1.7 months in NMOSD. Mild adverse drug reactions occurred in 44% of patients. RTX effectively prevents relapses in Thai MS and NMOSD patients, with no observed serious adverse drug reactions.

Efficacy and safety of rituximab in multiple sclerosis: a systematic review and meta-analysis

OBJECTIVE

We aimed to synthesize all available observational studies and clinical trials of rituximab to estimate the safety and efficacy of this monoclonal antibody in people with multiple sclerosis (MS).

METHODS

The four databases including PubMed, Scopus, Embase, and Web of Science were comprehensively searched in April 2022. We defined PICO as follows. Problem or study population (P): patients with MS; intervention (I): Rituximab; comparison (C): none; outcome (O): efficacy and safety.

RESULTS

After two-step screening, a total of 27 studies entered into our qualitative and quantitative synthesis. Our analysis showed a significant decrease in EDSS score in all patients with MS after treatment (SMD: - 0.44, 95% CI - 0.85, - 0.03). In addition, the ARR was reduced after using rituximab compared to the pre-treatment period (SMD: - 0.65, 95% CI - 1.55, 0.24) but it was not significant. The most common side effect after rituximab with a pooled prevalence of 28.63% (95% CI 16.61%, 42.33%). Furthermore, the pooled prevalence of infection was 24% in patients with MS (95% CI 13%, 36%). In the end, the pooled prevalence of malignancies after rituximab treatment was 0.39% (95% CI 0.02%, 1.03%).

CONCLUSION

Our findings illustrated an acceptable safety for this treatment. However, further studies with randomized design, long follow-up, and large sample sizes are needed to confirm the safety and efficacy of rituximab in patients with MS.

The CLARION study: first report on safety findings in patients newly initiating treatment with cladribine tablets or fingolimod for multiple sclerosis

OBJECTIVES

As part of the CLARION study: (1) characterize the incidence of severe infections, herpes zoster, and malignancies in patients newly initiating cladribine or fingolimod for relapsing multiple sclerosis (MS); (2) estimate the incidence of severe lymphopenia among cladribine users; and (3) describe prior/subsequent disease-modifying therapy (DMT) in both cohorts.

METHODS

Patients were identified from seven participating MS registries/data sources. The incidence rate (IR) of each outcome per 1000 patient-years and its 95% confidence interval (95%CI) were estimated for cohorts using Poisson regression.

RESULTS

By cut-off date (01-April-2020), 742 cladribine and 867 fingolimod users were included. Mean follow-up was ∼1 year. The IR for severe infections from all contributing sources (except Denmark) was: cladribine, 7.37 (2.76,19.6); fingolimod, 6.55 (2.46,17.4). The corresponding IR for herpes zoster was 5.51 (1.78,17.1) and 3.27 (0.82,13.1), respectively, while values for opportunistic infections were 0 (0,6.76) and 1.63 (0.23,11.6), respectively. There were no events of progressive multifocal leukoencephalopathy in either cohort. The IR of severe lymphopenia was 63.9 (40.7,100.1) in 349 cladribine users from contributing sources. The IR of malignancies (cut-off date 01-April-2022) was 3.55 (1.59,7.90) for the cladribine cohort (n = 1035) and 3.55 (1.48,8.52) for the fingolimod cohort (n = 843) from three MS registries/data sources. In the combined data sources, 36.8% of cladribine and 27.4% of fingolimod users were DMT-naïve; after initiation of study treatment, 2.5% and 20.2% switched to another DMT, respectively.

CONCLUSION

No new safety signal was observed in patients treated with cladribine tablets, although results are limited by a relatively short duration of follow-up.

Efficacy and Safety of Proposed Biosimilar Natalizumab (PB006) in Patients With Relapsing-Remitting Multiple Sclerosis: The Antelope Phase 3 Randomized Clinical Trial

Importance

Proposed biosimilar natalizumab (biosim-NTZ) PB006 is the first biosimilar monoclonal antibody therapy developed for multiple sclerosis (MS) treatment.

Objective

To evaluate matching efficacy, safety, and immunogenicity between biosim-NTZ and reference natalizumab (ref-NTZ) in patients with relapsing-remitting MS (RRMS).

Design, Setting, and Participants

The Antelope trial was a phase 3, parallel-group, randomized, active-controlled study, conducted between October 2019 and March 2021, with last patient follow-up visit on August 23, 2021. The study took place in 48 centers in 7 countries. Of 531 patients with RRMS aged 18 to 60 years screened, 266 were excluded before randomization in line with study criteria. Eligible participants had 1 or more documented relapse within the previous year and either 1 or more gadolinium-enhancing T1-weighted or 9 or more T2-weighted brain lesions, Kurtzke Expanded Disability Status Scale score of 0 to 5.0 (inclusive), and John Cunningham virus index of 1.5 or less at screening. One patient withdrew consent before dosing.

Interventions

Intravenous infusions every 4 weeks of biosim-NTZ, 300 mg, or ref-NTZ, 300 mg (1:1 randomization), from week 0 to week 44 (end-of-study visit: week 48). At week 24, the ref-NTZ group was rerandomized and 30 patients were switched to biosim-NTZ for the remainder of the study.

Main Outcomes and Measures

The primary end point was the cumulative number of new active lesions on magnetic resonance imaging (new gadolinium-enhancing T1-weighted lesions and new/enlarging T2-weighted lesions without double counting) over 24 weeks. Additional end points included further magnetic resonance imaging parameters, annualized relapse rate, and Kurtzke Expanded Disability Status Scale score. Safety, tolerability, and immunogenicity assessments included adverse events, laboratory evaluations, and positivity for anti-John Cunningham virus antibodies and antinatalizumab antibodies.

Results

A total of 264 participants (mean [SD] age, 36.7 [9.38] years; 162 [61.4%] female) received treatment with biosim-NTZ (n = 131) or ref-NTZ (n = 133). At week 24, the model-based mean difference in cumulative number of new active lesions between biosim-NTZ and ref-NTZ treatment groups was 0.17 (least square means [SE]: biosim-NTZ, 0.34 [0.34]; ref-NTZ, 0.45 [0.28]; 95% CI, -0.61 to 0.94 within the prespecified margins of ±2.1). No significant differences between treatment groups were observed across secondary efficacy end points, safety, tolerability, or immunogenicity assessments.

Conclusions and Relevance

Biosim-NTZ matched ref-NTZ in efficacy, safety, and immunogenicity for patients with RRMS in the tested setting. This phase 3 trial supports proposed biosim-NTZ as a biosimilar alternative to ref-NTZ for treating RRMS.

Trial Registration

ClinicalTrials.gov Identifier: NCT04115488.

Treatment of multiple sclerosis with rituximab: A Spanish multicenter experience

Introduction

Rituximab (RTX) is considered a potential therapeutic option for relapsing-remitting (RRMS) and progressive forms (PMS) of multiple sclerosis (MS). The main objective of this work was to investigate the effectiveness and safety of rituximab in MS.

Patients and methods

Observational multicenter study of clinical and radiological effectiveness and safety of rituximab in RRMS and PMS.

Results

A total of 479 rituximab-treated patients were included in 12 Spanish centers, 188 RRMS (39.3%) and 291 (60.7%) PMS. Despite standard treatment, the annualized relapse rate (ARR) the year before RTX was 0.63 (SD: 0.8) and 156 patients (41%) had at least one gadolinium-enhanced lesion (GEL) on baseline MRI. Mean EDSS had increased from 4.3 (SD: 1.9) to 4.8 (SD: 1.7) and almost half of the patients (41%) had worsened at least one point. After a median follow-up of 14.2 months (IQR: 6.5-27.2), ARR decreased by 85.7% (p < 0.001) and GEL by 82.9%, from 0.41 to 0.07 (p < 0.001). A significant decrease in EDSS to 4.7 (p = 0.046) was observed after 1 year of treatment and this variable remained stable during the second year of therapy. There was no evidence of disease activity in 68% of patients. Infusion-related symptoms were the most frequent side effect (19.6%) and most were mild. Relevant infections were reported only in 18 patients (including one case of probable progressive multifocal leukoencephalopathy).

Conclusion

Rituximab could be an effective and safe treatment in RRMS, including aggressive forms of the disease. Some selected PMS patients could also benefit from this treatment.

The prevalence of cancer in patients with multiple sclerosis (MS) who received rituximab: a systematic review and meta-analysis

OBJECTIVE

To estimate the pooled prevalence of cancer in patients with multiple sclerosis (MS) cases who were under treatment with rituximab.

METHODS

We searched PubMed, Scopus, EMBASE, Web of Science, and google scholar along with gray literature up to April 2021. The search strategy included the MeSH and text words as (("CD20 Antibody" AND Rituximab) OR "Rituximab CD20 Antibody" OR Mabthera OR "IDEC-C2B8 Antibody" OR "IDEC C2B8 Antibody" OR IDEC-C2B8 OR "IDEC C2B8" OR GP2013 OR Rituxan OR rituximab) AND ((Sclerosis AND multiple) OR (sclerosis AND disseminated) OR "disseminated sclerosis" OR "multiple sclerosis" OR "acute fulminating").

RESULTS

The literature search revealed 3577 articles, after deleting duplicates 2066 remained. For the meta-analysis, 22 studies were included. Totally, 15599 patients were enrolled while 133 cancers were detected. The pooled prevalence of cancer in MS patients under treatment with rituximab is 1in 100,000 (I2 = 99.9%, p < 0.001).

CONCLUSION

The results of this systematic review and meta-analysis show that the pooled prevalence of cancer in MS patients who received rituximab is 1 in 100,000 cases.

Effect of Rituximab Compared with Natalizumab and Fingolimod in Patients with Relapsing-Remitting Multiple Sclerosis: A Cohort Study

The objective of this study was to evaluate the clinical files of patients with RRMS who started rituximab (RTX) compared with a second-line treatment (natalizumab (NTZ) or fingolimod (FTY)). This was a historical cohort study. We compared the effect according to the Expanded Disability Status Scale (EDSS) and the number of relapses in RRMS patients receiving these treatments after a mean period of 12 months. We found a statistically significant difference (p < 0.001) when comparing the EDSS scores and the annual relapse rates of patients receiving RTX with those receiving NTZ or FTY. This study is essential for our clinical practice, since patients with limited treatment options represent a challenge with regard to the management of their medical care. However, clinical trials and prospective studies with long follow-up periods are necessary to provide sufficient evidence on the efficacy of RTX and thus include this treatment in the therapeutic profile of patients with MS.

Rituximab for people with multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is the most common neurological cause of disability in young adults. Off-label rituximab for MS is used in most countries surveyed by the International Federation of MS, including high-income countries where on-label disease-modifying treatments (DMTs) are available.  OBJECTIVES: To assess beneficial and adverse effects of rituximab as 'first choice' and as 'switching' for adults with MS.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, and trial registers for completed and ongoing studies on 31 January 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and controlled non-randomised studies of interventions (NRSIs) comparing rituximab with placebo or another DMT for adults with MS.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology. We used the Cochrane Collaboration's tool for assessing risk of bias. We rated the certainty of evidence using GRADE for: disability worsening, relapse, serious adverse events (SAEs), health-related quality of life (HRQoL), common infections, cancer, and mortality. We conducted separate analyses for rituximab as 'first choice' or as 'switching', relapsing or progressive MS, comparison versus placebo or another DMT, and RCTs or NRSIs.

MAIN RESULTS

We included 15 studies (5 RCTs, 10 NRSIs) with 16,429 participants of whom 13,143 were relapsing MS and 3286 progressive MS. The studies were one to two years long and compared rituximab as 'first choice' with placebo (1 RCT) or other DMTs (1 NRSI), rituximab as 'switching' against placebo (2 RCTs) or other DMTs (2 RCTs, 9 NRSIs). The studies were conducted worldwide; most originated from high-income countries, six from the Swedish MS register. Pharmaceutical companies funded two studies. We identified 14 ongoing studies. Rituximab as 'first choice' for relapsing MS Rituximab versus placebo: no studies met eligibility criteria for this comparison. Rituximab versus other DMTs: one NRSI compared rituximab with interferon beta or glatiramer acetate, dimethyl fumarate, natalizumab, or fingolimod in active relapsing MS at 24 months' follow-up. Rituximab likely results in a large reduction in relapses compared with interferon beta or glatiramer acetate (hazard ratio (HR) 0.14, 95% confidence interval (CI) 0.05 to 0.39; 335 participants; moderate-certainty evidence). Rituximab may reduce relapses compared with dimethyl fumarate (HR 0.29, 95% CI 0.08 to 1.00; 206 participants; low-certainty evidence) and natalizumab (HR 0.24, 95% CI 0.06 to 1.00; 170 participants; low-certainty evidence). It may make little or no difference on relapse compared with fingolimod (HR 0.26, 95% CI 0.04 to 1.69; 137 participants; very low-certainty evidence). The study reported no deaths over 24 months. The study did not measure disability worsening, SAEs, HRQoL, and common infections. Rituximab as 'first choice' for progressive MS One RCT compared rituximab with placebo in primary progressive MS at 24 months' follow-up. Rituximab likely results in little to no difference in the number of participants who have disability worsening compared with placebo (odds ratio (OR) 0.71, 95% CI 0.45 to 1.11; 439 participants; moderate-certainty evidence). Rituximab may result in little to no difference in recurrence of relapses (OR 0.60, 95% CI 0.18 to 1.99; 439 participants; low-certainty evidence), SAEs (OR 1.25, 95% CI 0.71 to 2.20; 439 participants; low-certainty evidence), common infections (OR 1.14, 95% CI 0.75 to 1.73; 439 participants; low-certainty evidence), cancer (OR 0.50, 95% CI 0.07 to 3.59; 439 participants; low-certainty evidence), and mortality (OR 0.25, 95% CI 0.02 to 2.77; 439 participants; low-certainty evidence). The study did not measure HRQoL. Rituximab versus other DMTs: no studies met eligibility criteria for this comparison. Rituximab as 'switching' for relapsing MS  One RCT compared rituximab with placebo in relapsing MS at 12 months' follow-up. Rituximab may decrease recurrence of relapses compared with placebo (OR 0.38, 95% CI 0.16 to 0.93; 104 participants; low-certainty evidence). The data did not confirm or exclude a beneficial or detrimental effect of rituximab relative to placebo on SAEs (OR 0.90, 95% CI 0.28 to 2.92; 104 participants; very low-certainty evidence), common infections (OR 0.91, 95% CI 0.37 to 2.24; 104 participants; very low-certainty evidence), cancer (OR 1.55, 95% CI 0.06 to 39.15; 104 participants; very low-certainty evidence), and mortality (OR 1.55, 95% CI 0.06 to 39.15; 104 participants; very low-certainty evidence). The study did not measure disability worsening and HRQoL.  Five NRSIs compared rituximab with other DMTs in relapsing MS at 24 months' follow-up. The data did not confirm or exclude a beneficial or detrimental effect of rituximab relative to interferon beta or glatiramer acetate on disability worsening (HR 0.86, 95% CI 0.52 to 1.42; 1 NRSI, 853 participants; very low-certainty evidence). Rituximab likely results in a large reduction in relapses compared with interferon beta or glatiramer acetate (HR 0.18, 95% CI 0.07 to 0.49; 1 NRSI, 1383 participants; moderate-certainty evidence); and fingolimod (HR 0.08, 95% CI 0.02 to 0.32; 1 NRSI, 256 participants; moderate-certainty evidence). The data did not confirm or exclude a beneficial or detrimental effect of rituximab relative to natalizumab on relapses (HR 1.0, 95% CI 0.2 to 5.0; 1 NRSI, 153 participants; very low-certainty evidence). Rituximab likely increases slightly common infections compared with interferon beta or glatiramer acetate (OR 1.71, 95% CI 1.11 to 2.62; 1 NRSI, 5477 participants; moderate-certainty evidence); and compared with natalizumab (OR 1.58, 95% CI 1.08 to 2.32; 2 NRSIs, 5001 participants; moderate-certainty evidence). Rituximab may increase slightly common infections compared with fingolimod (OR 1.26, 95% CI 0.90 to 1.77; 3 NRSIs, 5187 participants; low-certainty evidence). It may make little or no difference compared with ocrelizumab (OR 0.02, 95% CI 0.00 to 0.40; 1 NRSI, 472 participants; very low-certainty evidence). The data did not confirm or exclude a beneficial or detrimental effect of rituximab on mortality compared with fingolimod (OR 5.59, 95% CI 0.22 to 139.89; 1 NRSI, 136 participants; very low-certainty evidence) and natalizumab (OR 6.66, 95% CI 0.27 to 166.58; 1 NRSI, 153 participants; very low-certainty evidence). The included studies did not measure SAEs, HRQoL, and cancer.

AUTHORS' CONCLUSIONS

For preventing relapses in relapsing MS, rituximab as 'first choice' and as 'switching' may compare favourably with a wide range of approved DMTs. A protective effect of rituximab against disability worsening is uncertain. There is limited information to determine the effect of rituximab for progressive MS.  The evidence is uncertain about the effect of rituximab on SAEs. They are relatively rare in people with MS, thus difficult to study, and they were not well reported in studies. There is an increased risk of common infections with rituximab, but absolute risk is small.  Rituximab is widely used as off-label treatment in people with MS; however, randomised evidence is weak. In the absence of randomised evidence, remaining uncertainties on beneficial and adverse effects of rituximab for MS might be clarified by making real-world data available.