Late-onset neutropenia after RITUXIMAB therapy for multiple sclerosis, neuromyelitis optica spectrum disorders and MOG-antibody-associated diseases

Recurrent late-onset neutropenia following treatment with different B cell-depleting strategies in multiple sclerosis

BACKGROUND

As B cell-depleting therapies in multiple sclerosis (MS) have gained significant importance in the last several years, their long-term safety profile is of considerable clinical interest. Late-onset neutropenia (LON) is a rare, but potentially severe, adverse event that was first described in patients with rheumatic disorders under therapy with rituximab. Ofatumumab was approved in 2021 for the treatment of relapsing-remitting multiple sclerosis (RRMS). Neutropenia occurred in 0.2% of patients in clinical phase 3 trials, and to date, no cases of LON have been reported under ofatumumab treatment.

METHODS

Here, we report a case of repetitive symptomatic LON under ocrelizumab as well as ofatumumab treatment. Additionally, we review the literature on rare occurrences of LON in patients with MS, neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) undergoing B cell-depleting therapies, including rituximab, ocrelizumab, ofatumumab, inebilizumab, and ublituximab.

FINDINGS

In our case, the patient presented with repetitive symptomatic LON under ocrelizumab as well as ofatumumab treatment leading to febrile infections, subsequent use of antibiotics, and application of granulocyte-colony-stimulating factor. After repetitive episodes of LON under both B cell-depleting strategies, cladribine was subsequently initiated. A nine-month follow-up showed a normal neutrophil count and no evidence of disease activity.

CONCLUSIONS

This case highlights the significance of symptomatic late-onset blood count changes under both ocrelizumab and ofatumumab and emphasizes the importance of continuous monitoring of the differential blood count under B cell-depleting treatment.

FUNDING

This study was supported by the Deutsche Forschungsgemeinschaft (DFG; SFB CRC-TR-128 to F.Z., V.F., and S.B..; SFB 1080 and SFB CRC-1292 to F.Z..; and SFB/TRR 355 to S.B.) and the Hermann and Lilly Schilling Foundation (to S.B.).

The pharmacological management of myelin oligodendrocyte glycoprotein-immunoglobulin G associated disease (MOGAD): an update of the literature

INTRODUCTION

Myelin oligodendrocyte glycoprotein-immunoglobulin G associated disease (MOGAD) is a clinical entity distinct from multiple sclerosis and aquaporin-4 (AQP4+)-IgG-positive neuromyelitis optica spectrum disorder. There is a lack of evidence regarding the efficacy and safety of current treatments used for MOGAD.

AREAS COVERED

In this article, the authors review the currently available literature on the pharmacological management of MOGAD. This article is based on an extensive search for articles including meta-analyses, clinical trials, systematic reviews, observational studies, case series and case reports.

EXPERT OPINION

Intravenous high-dose methylprednisolone is the most common therapy for acute attack with patients having a good treatment response. In cases with poor recovery, intravenous immunoglobulins (IVIG) or plasma-exchange proved to be effective. Maintenance therapies include mycophenolate mofetil, azathioprine, IVIG, oral corticosteroids, rituximab, and interleukin-6 receptor (IL6-R) antagonists. Rituximab is the most used drug while IL6-R antagonists emerged as an effective option for people not responding to current treatments. Larger prospective studies with longer follow-ups are needed to confirm whether the blockage of the IL6-R is an effective and safe option. Since there is no evidence of major safety issues related to the new available therapies, the authors believe that waiting for disease activity to consider a possible treatment change, is an unwise approach.

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.

Rituximab and pregnancy: Late-onset neutropenia in a 2-month infant whose mother received rituximab 2 weeks prior to childbirth

Late-onset neutropenia (LON) is a rare adverse event that has not been reported from in utero exposure. We describe a case of LON in an infant, whose mother had neuromyelitis optica and received rituximab in the third trimester due to re-emergence of CD19 B cells. The newborn was born without complications but 2 months later was found to have grade IV neutropenia. No etiology was identified. Neutropenia self-resolved within 1 week. This case emphasizes an unmet need for developing guidelines and protocols to manage in utero rituximab exposure.

A Case of Late-Onset Neutropenia in Relapsing-Remitting Multiple Sclerosis Following Ocrelizumab Therapy

Ocrelizumab, a monoclonal antibody, has proven effective in treating both primary progressive and relapsing-remitting multiple sclerosis. Common adverse effects observed in clinical studies include flushing, sore throat, pruritus, and rash. This abstract discusses a case of severe, late-onset neutropenia in a patient with relapsing-remitting multiple sclerosis undergoing ocrelizumab treatment. The neutropenia emerged 46 days following the patient's most recent ocrelizumab dose. The patient responded well to treatment with intravenous meropenem and filgrastim. This rare and unforeseen adverse effect highlights the importance of regular blood monitoring for early detection of severe neutropenia in patients treated with ocrelizumab.

Update on the diagnosis and treatment of neuromyelitis optica spectrum disorders (NMOSD) - revised recommendations of the Neuromyelitis Optica Study Group (NEMOS). Part II: Attack therapy and long-term management

This manuscript presents practical recommendations for managing acute attacks and implementing preventive immunotherapies for neuromyelitis optica spectrum disorders (NMOSD), a rare autoimmune disease that causes severe inflammation in the central nervous system (CNS), primarily affecting the optic nerves, spinal cord, and brainstem. The pillars of NMOSD therapy are attack treatment and attack prevention to minimize the accrual of neurological disability. Aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) are a diagnostic marker of the disease and play a significant role in its pathogenicity. Recent advances in understanding NMOSD have led to the development of new therapies and the completion of randomized controlled trials. Four preventive immunotherapies have now been approved for AQP4-IgG-positive NMOSD in many regions of the world: eculizumab, ravulizumab - most recently-, inebilizumab, and satralizumab. These new drugs may potentially substitute rituximab and classical immunosuppressive therapies, which were as yet the mainstay of treatment for both, AQP4-IgG-positive and -negative NMOSD. Here, the Neuromyelitis Optica Study Group (NEMOS) provides an overview of the current state of knowledge on NMOSD treatments and offers statements and practical recommendations on the therapy management and use of all available immunotherapies for this disease. Unmet needs and AQP4-IgG-negative NMOSD are also discussed. The recommendations were developed using a Delphi-based consensus method among the core author group and at expert discussions at NEMOS meetings.

Predictors of hospitalization due to infection in rituximab-treated MS patients

BACKGROUND

Rituximab is extensively used off-label to treat multiple sclerosis (MS), and long-term vigilance for adverse events is needed. This study was conducted to determine frequencies and predictors of hematological adverse events, including hypogammaglobulinemia, severe lymphopenia, neutropenia, and infections leading to hospitalization.

METHODS

This retrospective cohort study included all patients with MS initiating rituximab treatment at Haukeland University Hospital between January 1^st, 2017, and July 1^st, 2021. Patients were followed by clinical monitoring and repeated blood sampling every six months. Clinical outcomes and laboratory results were retrieved from the Norwegian MS Registry and Biobank and the patient administrative system at Haukeland University Hospital.

RESULTS

Five hundred and fifty-six patients were included, 515 with relapsing-remitting MS (RRMS) and 41 with progressive MS. Overall, 33 patients (5.9%) experienced 56 episodes of infections requiring hospital admission. Sixty patients (10.8%) had confirmed hypogammaglobulinemia, 17 (3.1%) had confirmed severe lymphopenia, and 10 (1.8%) had confirmed severe neutropenia. Predictors of infection requiring hospital admission were progressive MS (adjusted OR (aOR): 4.81; 95%CI: 1.25-18.48), duration of treatment with rituximab (aOR: 1.52; 95%CI: 1.11-2.09) and confirmed severe lymphopenia (aOR: 13.58; 95%CI: 3.41-54.06) and neutropenia (aOR: 13.40; 95%CI: 2.93-61.25). Of the hematological abnormalities, only hypogammaglobulinemia was associated with treatment duration (aOR: 1.35; 95%CI: 1.09-1.69).

CONCLUSION

The risk of hospitalization due to infection is associated with time on rituximab treatment, in patients with lympho- or neutropenia, and in patients with primary progressive MS. We observed a time-dependent decline in IgG values, in contrast to neutrophil and lymphocyte count, suggesting a cumulative dose-dependent response. These predictors can assist clinicians in assessing and monitoring MS patients receiving rituximab.

Anti-CD20 therapies in multiple sclerosis: From pathology to the clinic

The immune system plays a significant role in multiple sclerosis. While MS was historically thought to be T cell-mediated, multiple pieces of evidence now support the view that B cells are essential players in multiple sclerosis pathogenic processes. High-efficacy disease-modifying therapies that target the immune system have emerged over the past two decades. Anti-CD20 monoclonal antibodies selectively deplete CD20+ B and CD20+ T cells and efficiently suppress inflammatory disease activity. These monotherapies prevent relapses, reduce new or active magnetic resonance imaging brain lesions, and lessen disability progression in patients with relapsing multiple sclerosis. Rituximab, ocrelizumab, and ofatumumab are currently used in clinical practice, while phase III clinical trials for ublituximab have been recently completed. In this review, we compare the four anti-CD20 antibodies in terms of their mechanisms of action, routes of administration, immunological targets, and pharmacokinetic properties. A deeper understanding of the individual properties of these molecules in relation to their efficacy and safety profiles is critical for their use in clinical practice.

Efficacy and safety of rituximab in myelin oligodendrocyte glycoprotein antibody-associated disorders compared with neuromyelitis optica spectrum disorder: a systematic review and meta-analysis

BACKGROUND

Rituximab (RTX) efficacy in patients with myelin oligodendrocyte glycoprotein (MOG) antibody-associated disorders (MOGADs) is still poorly understood, though it appears to be lower than in aquaporin-4-IgG-positive neuromyelitis optica spectrum disorders (AQP4-IgG+NMOSDs). The aim of this systematic review and meta-analysis is to assess the efficacy and safety profile of RTX in patients with MOGAD and to compare RTX efficacy between MOGAD and AQP4-IgG+NMOSD.

METHODS

We searched original English-language articles published between 2012 and 2021 in MEDLINE, Cochrane, Central Register of Controlled Trials and clinicaltrials.gov, reporting data on RTX efficacy in patients with MOGAD. The main outcome measures were annualised relapse rate (ARR) and Expanded Disability Status Scale (EDSS) score mean differences (MDs) after RTX. The meta-analysis was performed with a random effects model. Covariates associated with the outcome measures were analysed with a linear meta-regression.

RESULTS

The systematic review included 315 patients (138 women, mean onset age 26.8 years) from 32 studies. Nineteen studies (282 patients) were included in the meta-analysis. After RTX, a significant decrease of ARR was found (MD: -0.92, 95% CI -1.24 to -0.60, p<0.001), markedly different from the AQP4-IgG+NMOSD (MD: -1.73 vs MOGAD -0.92, subgroup difference testing: Q=9.09, p=0.002). However, when controlling for the mean ARR pre-RTX, this difference was not significant. After RTX, the EDSS score decreased significantly (MD: -0.84, 95% CI -1.41 to -0.26, p=0.004). The frequency of RTX-related adverse events was 18.8% (36/192) and overall RTX-related mortality 0.5% (1/192).

CONCLUSIONS

RTX showed effective in MOGAD, although to a lesser extent than in AQP4-IgG+NMOSD, while the safety profile warrants some caution in its prescription. Randomised-controlled trials are needed to confirm these findings and provide robust evidence to improve treatment strategies in patients with MOGAD.

PROSPERO REGISTRATION NUMBER

CRD42020175439.

Rituximab for the treatment of multiple sclerosis: a review

In the last decades, evidence suggesting the direct or indirect involvement of B cells on multiple sclerosis (MS) pathogenesis has accumulated. The increased amount of data on the efficacy and safety of B-cell-depleting therapies from several studies has suggested the addition of these drugs as treatment options to the current armamentarium of disease modifying therapies (DMTs) for MS. Particularly, rituximab (RTX), a chimeric monoclonal antibody directed at CD20 positive B lymphocytes resulting in cell-mediated apoptosis, has been demonstrated to reduce inflammatory activity, incidence of relapses and new brain lesions on magnetic resonance imaging (MRI) in patients with relapsing-remitting MS (RRMS). Additional evidence also demonstrated that patients with progressive MS (PMS) may benefit from RTX, which also showed to be well tolerated, with acceptable safety risks and favorable cost-effectiveness profile.Despite these encouraging results, RTX is currently approved for non-Hodgkin's lymphoma, chronic lymphocytic leukemia, several forms of vasculitis and rheumatoid arthritis, while it can only be administered off-label for MS treatment. Between Northern European countries exist different rules for using not licensed drug for treating MS. The Sweden MS register reports a high rate (53.5%) of off-label RTX prescriptions in relation to other annually started DMTs to treat MS patients, while Danish and Norwegian neurologists have to use other anti-CD20 drugs, as ocrelizumab, in most of the cases.In this paper, we review the pharmacokinetics, pharmacodynamics, clinical efficacy, safety profile and cost effectiveness aspects of RTX for the treatment of MS. Particularly, with the approval of new anti-CD20 DMTs, the recent worldwide COVID-19 emergency and the possible increased risk of infection with this class of drugs, this review sheds light on the use of RTX as an alternative treatment option for MS management, while commenting the gaps of knowledge regarding this drug.

Late-onset neutropenia after anti-CD20 therapy for multiple sclerosis, neuromyelitis optica spectrum disorders and MOG antibody-associated disease: A prospective study

Late-onset neutropenia (LON) after anti-CD20 therapy is a poorly described side effect in inflammatory disorders of the CNS. In this prospective study, patients treated with Rituximab or Ocrelizumab for MS, neuromyelitis optica spectrum disorders or MOG antibody-associated disease (MOGAD) were asked to perform complete blood count (CBC) every two weeks for six months, with the aim of identifying LON. Out of 152 patients, two (1,32%) had an absolute neutrophil count <1,000/mm³: one patient with MOGAD had agranulocytosis and one patient with MS had grade 3 neutropenia. Both were asymptomatic. These results confirm that LON after anti-CD20 therapy in inflammatory disorders of the CNS is not exceptional. Nevertheless, this biological complication remains too infrequent to justify close systematic CBC follow-up.

Targeting B cells in multiple sclerosis

PURPOSE OF REVIEW

Treatments targeting B cells are increasingly used for patients with multiple sclerosis (MS). We review the mechanisms of action, clinical effectiveness and safety of treatment, with emphasis on recently published studies.

RECENT FINDINGS

Several monoclonal antibodies targeting the surface molecule CD20 on B cells are approved or being developed for treatment of MS. Overall, they seem comparable in terms of strongly suppressing radiological disease activity and relapse biology. Novel approaches include anti-CD19 antibody therapy and treatment with oral drugs targeting Bruton's tyrosine kinase (BTK). The main safety issue with persistent B cell depletion is an increased risk of infections - possibly including an increased risk of severe COVID-19. Vaccine responses are also blunted in patients treated with anti-CD20 antibodies. Lower doses or longer infusion intervals may be sufficient for control of disease activity. Whether this might also improve the safety of treatment and increase vaccination responses remains to be determined.

SUMMARY

Available data support the widespread use of therapies targeting B cells in MS. Whether novel approaches targeting CD19 or BTK will have advantages compared to anti-CD20 antibody therapy remains to be established. Furthermore, trials investigating alternative dosing regimens for anti-CD20 antibody treatment are warranted.

The Pharmacogenetics of Rituximab: Potential Implications for Anti-CD20 Therapies in Multiple Sclerosis

There are a broad range of disease-modifying therapies (DMTs) available in relapsing-remitting multiple sclerosis (RRMS), but limited biomarkers exist to personalise DMT choice. All DMTs, including monoclonal antibodies such as rituximab and ocrelizumab, are effective in preventing relapses and preserving neurological function in MS. However, each agent harbours its own risk of therapeutic failure or adverse events. Pharmacogenetics, the study of the effects of genetic variation on therapeutic response or adverse events, could improve the precision of DMT selection. Pharmacogenetic studies of rituximab in MS patients are lacking, but pharmacogenetic markers in other rituximab-treated autoimmune conditions have been identified. This review will outline the wider implications of pharmacogenetics and the mechanisms of anti-CD20 agents in MS. We explore the non-MS rituximab literature to characterise pharmacogenetic variants that could be of prognostic relevance in those receiving rituximab, ocrelizumab or other monoclonal antibodies for MS.

Autoantibodies against central nervous system antigens in a subset of B cell-dominant multiple sclerosis patients

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS), with characteristic inflammatory lesions and demyelination. The clinical benefit of cell-depleting therapies targeting CD20 has emphasized the role of B cells and autoantibodies in MS pathogenesis. We previously introduced an enzyme-linked immunospot spot (ELISpot)-based assay to measure CNS antigen-specific B cells in the blood of MS patients and demonstrated its usefulness as a predictive biomarker for disease activity in measuring the successful outcome of disease-modifying therapies (DMTs). Here we used a planar protein array to investigate CNS-reactive antibodies in the serum of MS patients as well as in B cell culture supernatants after polyclonal stimulation. Anti-CNS antibody reactivity was evident in the sera of the MS cohort, and the antibodies bound a heterogeneous set of molecules, including myelin, axonal cytoskeleton, and ion channel antigens, in individual patients. Immunoglobulin reactivity in supernatants of stimulated B cells was directed against a broad range of CNS antigens. A group of MS patients with a highly active B cell component was identified by the ELISpot assay. Those antibody reactivities remained stable over time. These assays with protein arrays identify MS patients with a highly active B cell population with antibodies directed against a swathe of CNS proteins.

Remission of early persistent cladribine-induced neutropenia after filgrastim therapy in a patient with Relapsing - Remitting Multiple Sclerosis

BACKGROUND

Cladribine tablets were recently approved for the treatment of Relapsing-Remitting Multiple Sclerosis (RRMS), reducing B cells and T cells, followed by reconstitution of the adaptive immune system, with transient and mild effects on the innate one. Cladribine is also the standard first-line and subsequent treatment for Hairy-Cell Leukemia (HCL), frequently complicated by neutropenic fever. Recombinant human Granulocyte Colony-Stimulating Factor (G-CSF; Filgrastim) has been proved to reduce neutropenia by increasing neutrophil count.

CASE REPORT

To the best of our knowledge, we report the first case of early and persistent high grade non febrile neutropenia after oral cladribine therapy in a 49-year-old RR-MS patient, successfully treated with Filgrastim.

CONCLUSIONS

This report suggests that in selected cases, cladribine requires early monitoring of blood sample as it may be responsible for early neutropenia, requiring specific treatment.