An update on the evidence for the efficacy and safety of rituximab in the management of neuromyelitis optica

The correlation between rituximab dose reduction and acute relapses of neuromyelitis optica spectrum disorder, lessons from COVID-19 epidemic

BACKGROUND

COVID-19 was a viral infection that led to a global pandemic in March 2020. At the beginning of the pandemic, clinicians encountered the challenge of how immunosuppressive treatments would affect the course of COVID-19 infection in people with autoimmune diseases. Neuromyelitis optica spectrum disorder is an autoimmune astrocytopathy that is caused by an inflammation in the CNS. Major treatments to prevent acute relapses include immunosuppressive drugs. Rituximab is a well-established immunosuppressive agent in NMOSD maintenance therapy. Some reports suggested that treatment with Rituximab might increase the risk of COVID-19 infection and its mortality in NMOSD. On the other hand, dose reduction or extended interval treatment might lead to acute relapses of NMOSD and permanent disability.

METHODS

In this study, we evaluated the correlation between the dose of rituximab and the relapse rate of NMOSD during an epidemic. This was an observational study on 171 patients among whom 55 cases were seropositive. Some patients received full dose rituximab routinely (1000 mg/dose, every 6 months), but others were treated with half dose (500 mg/dose) during the epidemic. Also, some doses were prescribed with a delay, based on the level of CD19 and CD20.

RESULTS

The Pearson correlation coefficient (r) showed a negative and significant relation (r: - 0.19, p: 0.022) between the amount of drug and the number of relapses in the seropositive group, so low dosage of the drug was related to more acute relapses. In seronegative cases, there was not any valuable relationship. (p: 0.367).

CONCLUSION

Lower dose of rituximab, especially in seropositive NMOSD patients, can potentially lead to acute relapses. So, the more frequent evaluation of the CD19, CD20, and, CD27 levels, and the general clinical condition of the patients should be considered.

Long-term efficacy and safety of rituximab in the treatment of neuromyelitis Optica Spectrum disorder

Background

Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing, autoimmune, inflammatory astrocytopathy. Rituximab for B-cell suppression is a common treatment for NMOSD; however, large-scale randomised controlled trials are lacking.

Objective

Evaluate long-term efficacy and safety of rituximab for NMOSD.

Methods

Retrospective observational study of patients with NMOSD treated with rituximab. Annualised relapse rates (ARRs) before and during rituximab treatment were evaluated; Modified Rankin Scores (mRS) were measured as a marker of disability.

Results

In total, 37 patients were included: 27 aquaporin-4-IgG-seropositive and 10 seronegative NMOSD. The predominant rituximab dosing regimen was an initial 1000 mg, split over two 500 mg infusions, two weeks apart, followed by single 500 mg doses. Over a median follow-up of 54 months, ARR for the whole cohort was 0.136 (95% CI 0.088-0.201), significantly lower than the pretreatment ARR of 0.366 (95% CI 0.271-0.483, p < 0.001). There was a significant reduction in ARR for the seropositive subgroup, but not seronegative. Significant improvement in mRS was seen post-treatment. Infections were reported in 32% of patients during follow-up; most were mild.

Conclusion

Rituximab, at doses lower than traditionally used, may be an efficacious therapy for NMOSD, with a favourable safety profile.

Rituximab induces a transient fluctuation of peripheral and follicular helper T cells in neuromyelitis optica spectrum disorder

Autoreactive CD4+ helper T cells are implicated in the pathogenesis of neuromyelitis optica spectrum disorder (NMOSD). Both PD-1+CXCR5+CD4+ T follicular helper (Tfh) cells and PD-1+CXCR5-CD4+ T peripheral helper (Tph) cells can contribute to B-cell immune responses and the production of antibodies. Here we show the effect of B-cell depletion with rituximab on the homeostasis of Tfh cells, Tph cells and their subsets in patients with NMOSD. After rituximab treatment, total Tph cells, total Tfh cells, Tph17 cells, Tph17.1 cells, Tph1 cells, and Tfh1 cells tended to decrease at month 1, but gradually increased at month 6 and restored at month 12. Besides, Tph17.1 cells and Tfh17.1 cells were correlated with the proportion of CD19- antibody-secreting cells. Our data suggest that rituximab induced a fluctuation of proinflammatory Tph and Tfh subsets within one year after initiation of the treatment.

Clinical and epidemiological correlates of treatment change in patients with NMOSD: insights from the CIRCLES cohort

OBJECTIVE

Neuromyelitis optica spectrum disorders (NMOSD) represent rare autoimmune diseases of the central nervous system largely targeting optic nerve(s) and spinal cord. The present analysis used real-world data to identify clinical and epidemiological correlates of treatment change in patients with NMOSD.

METHODS

CIRCLES is a longitudinal, observational study of NMOSD conducted at 15 centers across North America. Patients with ≥ 60 days of follow-up and receiving on-study maintenance treatment were evaluated. The mean annual relapse rate (ARR) was estimated using negative binomial models; the likelihood of treatment change was estimated using Cox proportional hazards models. Relapses were included as time-varying covariates to estimate the relationship to treatment change.

RESULTS

Of 542 patients included, 171 (31.5%) experienced ≥ 1 relapse on the study and 133 patients (24.5%) had ≥ 1 change in the treatment regimen. Two categories of variables significantly correlated with the likelihood of treatment change: (1) relapse: any on-study relapse (hazard ratio [HR] = 2.91; p < 0.001), relapse phenotypes (HR range = 2.15-5.49; p < 0.001), and pre-study ARR > 0.75 (HR 2.28; p < 0.001); 2) disease phenotype: brain syndrome only vs transverse myelitis involvement at onset (HR 2.44; p = 0.008), disease duration < 1 vs > 5 years (HR 1.66; p = 0.028), or autoimmune comorbidity (HR 1.55; p = 0.015). A subset of these factors significantly correlated with shorter time to first rituximab discontinuation.

CONCLUSIONS

In CIRCLES, relapse patterns and disease phenotype significantly correlated with changes in the maintenance treatment regimen. Such findings may facilitate the identification of patients with NMOSD who are likely to benefit from treatment change to reduce relapse risk or disease burden and enhance the quality of life.

B-cell proliferation characteristics and monitoring significance under the modified reduced-dose rituximab regimen for NMOSD: A real-world case series study

OBJECTIVE

To explore the B-cell proliferation characteristics and monitoring significance under the modified reduced-dose rituximab (mRTX) regimen for neuromyelitis optica spectrum disorder (NMOSD).

METHODS

NMOSD patients treated with mRTX were recruited, and the percentages of total CD19⁺ B cells and CD27⁺ memory B cells were dynamically detected by flow cytometry. The annualized relapse rate (ARR) and expanded disability status scale (EDSS) scores were compared before and after mRTX treatment, and the differences in B-cell values were compared between groups.

RESULTS

A total of 34 patients with NMOSD were ultimately enrolled. The EDSS score decreased from 2.5 (1.5, 3.0) to 1.3 (1.0, 2.0), and the ARR decreased from 1.0 (0, 2.0) to 0 (0, 0) (p < 0.001). Relapses occurred in 6 patients, with total CD19⁺ B-cell percentages of 3.25% (2.7%, 3.7%) and CD27⁺ memory B-cell percentages of 0.3% (0.2%, 0.3%) at initial relapse. Twenty-eight patients (82.4%) remained relapse-free with 84 doses of mRTX. Before 56 repeated doses, the total CD19⁺ B cells and CD27⁺ memory B cells were 4.00% (3.14%, 5.32%) and 0.26% (0.17%, 0.40%), respectively. The mean dosing interval was 9.2 months. Both total CD19⁺ B cells and CD27⁺ memory B cells proliferated over time after mRTX use, with significantly faster proliferation rates in the later stages. In 28 relapse-free patients, the mean time to reach 1% for total CD19⁺ B cells was 210 days, and the mean time to reach 3% was 240 days, with the mean interval from 1% to 3% of 65 days. Twenty-five relapse-free patients had no significant differences in maximum, minimum, and mean B-cell values compared to those of 6 patients with relapse.

CONCLUSION

The high rate of B-cell proliferation under the mRTX regimen indicates that closer dynamic B-cell monitoring is required to guide repeated mRTX dosing. Sustained depletion of total CD19⁺ B cells targeting < 3% of lymphocytes may be feasible, enabling extended dosing intervals.

An update on biologic treatments for neuromyelitis optica spectrum disorder

INTRODUCTION

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease of the central nervous system mediated by antibodies targeting the aquaporin-4 (AQP4) water channel expressed on astrocytes. The binding of specific antibodies to AQP4 causes complement-dependent cytotoxicity, leading to inflammation and demyelination. Several recent phase 2 and 3 randomized placebo-controlled trials showed the efficacy and safety of monoclonal antibody therapies targeting B-cells, interleukin-6 receptor, and complement.

AREAS COVERED

Current biologic treatments for NMOSD and developments therein, and unresolved issues in NMOSD treatment.

EXPERT OPINION

New biologic treatments demonstrate high efficacy and good safety for patients with AQP4-IgG-positive NMOSD. The optimal therapeutics for seronegative NMOSD, pediatric patients, and female patients who are pregnant or wish to be are unclear, and further research is needed. Also, real-world studies of new biological agents and the data on the durability of their beneficial effects and their long-term safety are required. Effective rescue therapy for an acute attack is critical given permanent disability in NMOSD is attack-related, and biologic agents that treat acute attack are emerging. If such treatments are to become widely applied, studies on the most cost-effective treatment strategies are needed.

Efficacy of monoclonal antibodies in neuromyelitis optica: An updated systematic review with meta‐analysis

Objective

This is a critical review of studies aiming to assess the safety and efficacy of monoclonal antibodies as compared with the classical regimen in patients with neuromyelitis optica spectrum disorder.

Methods

Various electronic databases were searched for original articles reporting results from the use of monoclonal antibodies in neuromyelitis optica spectrum disorder. The Expanded Disability Status Scale and annualized relapse rate score before and after treatment were the primary effect measures. The pooled standardized mean difference with 95% CI was calculated using the random effects model. The heterogeneity of the included studies was calculated using Cochran's Q test and I2 statistics.

Results

Of 36 included studies, meta‐analysis was carried out from 27 studies. The pooled analysis of 1010 patients showed a mean reduction in the mean annualized relapse rate ratio after tocilizumab therapy −2.45 (95% CI −3.13 to −1.77) to be higher compared with rituximab −1.49 (95% CI −1.81 to −1.17). Likewise, the mean reduction in the Expanded Disability Status Scale after tocilizumab was higher −1.10 (95% CI −1.75 to −0.44) compared with rituximab −0.80 (95% CI −1.11 to −0.48).

Conclusion

Tocilizumab has a greater effect than rituximab in terms of the reduction of the annualized relapse rate and Expanded Disability Status Scale in neuromyelitis optica spectrum disorder patients. The greater efficacy of tocilizumab could result from its multiple dynamic pharmacodynamics (i.e. its effect on interleukin‐6‐dependent inflammatory processes, involving CD20‐negative plasmablasts, pathogenic T cells and regulatory T cells) and to some degree due to heterogeneity in our study. Satralizumab (monotherapy or add‐on), eculizumab and inebilizumab (monotherapy) are effective in aquaporin‐4‐positive cases with good safety profiles. Ublituximab, bortezomib, bevacizumab and C1‐esterase inhibitors are both effective and safe add‐on drugs.

Adverse Events in NMOSD Therapy

Neuromyelitis optica spectrum disorders (NMOSD) are rare neurologic autoimmune diseases that have a poor prognosis if left untreated. For many years, generic oral immunosuppressants and repurposed monoclonal antibodies that target the interleukin-6 pathway or B cells were the mainstays of drug treatment. Recently, these drug treatments have been complemented by new biologics developed and approved specifically for NMOSD. In principle, all of these drugs are effective, but treatment recommendations that take this into account are still pending. Instead, the choice of a drug may depend on other criteria such as drug safety or tolerability. In this review, we summarise current knowledge on the adverse effects of azathioprine, mycophenolate mofetil, rituximab, tocilizumab, eculizumab, satralizumab, and inebilizumab in NMOSD. Infections, cytopenias, and infusion-related reactions are most common, but the data are as heterogeneous as the manifestations are diverse. Nevertheless, knowledge of safety issues may facilitate treatment choices for individual patients.

Vaccination in neuromyelitis optica spectrum disorders: Friend or enemy?

Neuromyelitis optica spectrum disorders (NMOSDs) are uncommon antibody-mediated autoimmune diseases of the central nervous system (CNS), mainly occurring in optic nerves and spinal cord, which can cause visual impairment, paralysis, and occasionally bulbar dysfunction. Such neurological deficits can adversely affect pulmonary functions and increase complicated infection risk. Besides, most NMOSD patients undergo immunosuppressive therapy. All these factors make NMOSD patients the potential high-risk group under the current pandemic of coronavirus disease 2019 (COVID-19). Meanwhile, COVID-19 infection has already been demonstrated as a risk factor for NMOSD relapses. This review discusses the basic immunology of vaccination and common problems, including immunogenicity, safety, and efficacy of vaccination on NMOSD patients. Additionally, we offered vaccination recommendations, health care and treatment advice for NMOSD patients under the background of COVID-19.

Efficacy and Safety of Low-Dose Rituximab in Anti-MuSK Myasthenia Gravis Patients: A Retrospective Study

PURPOSE

To evaluate the efficacy and safety of low dosages of rituximab (RTX) in the treatment of MuSK-antibody-positive MG patients.

PATIENTS AND METHODS

We retrospectively analyzed the data of MuSK-antibody-positive MG patients who were treated with low dosages of RTX from January 2018 to October 2021. The long-term treatment response to RTX was assessed by Myasthenia Gravis Foundation of America (MGFA) post-interventional status (PIS), Myasthenia Gravis Status and Treatment Intensity (MGSTI), dosage of steroid, MG-related activities of daily living (MG-ADL) and myasthenic muscle score (MMS) at the end of follow-up.

RESULTS

Clinical improvement was observed in all eight patients with follow-up for 8 to 29 months after treatment. At the last visit, complete stable remission had been achieved in one patient, pharmacologic remission in three patients, minimal manifestations status in three patients and improved in one patient based on the MGFA-PIS criteria. MGSTI level 2 or better had been reached in six (75%) patients at the last visit. The steroid dosage decreased from 60 mg at baseline to 15 mg at the last follow-up (p = 0.011). The average MG-ADL score decreased from 11 (range 7 to 15) to 0 (range 0 to 3; p = 0.011), and the MMS improved from 38.5 (range 24 to 60) to 100 (range 90 to 100; p = 0.012). These differences were all statistically significant. During RTX treatment and subsequent follow-up, 1 patient reported minor post-infusion malaise.

CONCLUSION

Low-dose RTX is effective and safe for treating anti-MuSK antibody positive MG patients. A long-term response is observed after treatment. Larger prospective studies are required to provide further evidence.

Th17-Related Cytokines as Potential Discriminatory Markers between Neuromyelitis Optica (Devic's Disease) and Multiple Sclerosis-A Review

Multiple sclerosis (MS) and Devic’s disease (NMO; neuromyelitis optica) are autoimmune, inflammatory diseases of the central nervous system (CNS), the etiology of which remains unclear. It is a serious limitation in the treatment of these diseases. The resemblance of the clinical pictures of these two conditions generates a partial possibility of introducing similar treatment, but on the other hand, a high risk of misdiagnosis. Therefore, a better understanding and comparative characterization of the immunopathogenic mechanisms of each of these diseases are essential to improve their discriminatory diagnosis and more effective treatment. In this review, special attention is given to Th17 cells and Th17-related cytokines in the context of their potential usefulness as discriminatory markers for MS and NMO. The discussed results emphasize the role of Th17 immune response in both MS and NMO pathogenesis, which, however, cannot be considered without taking into account the broader perspective of immune response mechanisms.

Treatment of Neuromyelitis Optica Spectrum Disorders

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune central nervous system (CNS) inflammatory disorder that can lead to serious disability and mortality. Females are predominantly affected, including those within the reproductive age. Most patients develop relapsing attacks of optic neuritis; longitudinally extensive transverse myelitis; and encephalitis, especially brainstem encephalitis. The majority of NMOSD patients are seropositive for IgG autoantibodies against the water channel protein aquaporin-4 (AQP4-IgG), reflecting underlying aquaporin-4 autoimmunity. Histological findings of the affected CNS tissues of patients from in-vitro and in-vivo studies support that AQP4-IgG is directly pathogenic in NMOSD. It is believed that the binding of AQP4-IgG to CNS aquaporin-4 (abundantly expressed at the endfoot processes of astrocytes) triggers astrocytopathy and neuroinflammation, resulting in acute attacks. These attacks of neuroinflammation can lead to pathologies, including aquaporin-4 loss, astrocytic activation, injury and loss, glutamate excitotoxicity, microglial activation, neuroinflammation, demyelination, and neuronal injury, via both complement-dependent and complement-independent pathophysiological mechanisms. With the increased understanding of these mechanisms underlying this serious autoimmune astrocytopathy, effective treatments for both active attacks and long-term immunosuppression to prevent relapses in NMOSD are increasingly available based on the evidence from retrospective observational data and prospective clinical trials. Knowledge on the indications and potential side effects of these medications are essential for a clear evaluation of the potential benefits and risks to NMOSD patients in a personalized manner. Special issues such as pregnancy and the coexistence of other autoimmune diseases require additional concern and meticulous care. Future directions include the identification of clinically useful biomarkers for the prediction of relapse and monitoring of the therapeutic response, as well as the development of effective medications with minimal side effects, especially opportunistic infections complicated by long-term immunosuppression.

Prolonged B-cell depletion after rituximab in AQP4-IgG-positive neuromyelitis optica spectrum disorder

Rituximab (a B-cell depleting monoclonal antibody) is increasingly utilized for treatment of different immune-mediated neurologic disorders, including aquaporin-4-IgG-positive neuromyelitis optica spectrum disorder (AQP4-IgG-NMOSD). After an initial treatment course, the drug is generally reinfused when peripheral blood B-cells levels re-increase >1% (usually after 6-12 months), or at fixed pre-planned 6-month intervals. We describe the unusual case of a 40-year-old woman with AQP4-IgG-NMOSD who showed a prolonged B-cell depletion for nearly five years after a single rituximab reinfusion. In similar rare patients with exceptionally long-lasting B-cell depletion, rituximab reinfusions at fixed pre-planned intervals would result in unnecessary treatment-related risks and health-care expenses.

Rituximab efficacy at different initial and maintenance doses in neuromyelitis optica spectrum disorder: Experience from a national health institute in México

BACKGROUND

NMOSD is an inflammatory disorder of the central nervous system that primarily affects the optic nerves and spinal cord. Rituximab (RTX) is a monoclonal antibody directed against CD20, an epitope expressed on pre-B and mature B cells. It has of wide use in several antibody-mediated autoimmune diseases.

OBJECTIVES

To demonstrate RTX clinical efficacy at different initial and maintenance doses administered in patients with NMOSD.

METHODS

In this retrospective/observational study we recruited subjects with NMOSD with at least one RTX infusion. Annual relapse rates (ARR) were compared in several induction and maintenance regimens with RTX in 66 patients with NMOSD.

RESULTS

Fifty-four (81.8%) were female and two thirds (66.7%) had positive anti-AQP4 antibodies. The most prevalent induction and maintenance regimens were 1000 mg on days 1 and 15 (51.5%) and 1000 mg every 6 months (40.9%), respectively. Overall, the annual relapse rate (ARR) decreased from 1.15 to 0.46 with RTX (p < 0.001). In patients with persistent relapses, the ARR decreased from 1.66 to 1.22, representing a relative risk reduction of 24%. Treatment with RTX decreased the ARR from 1.36 to 0.4 in the 500 mg induction and maintenance dose subgroup, and from 0.7 to 0.4 in the 1000 mg induction and maintenance dose subgroup.

CONCLUSION

RTX treatment in patients with NMOSD demonstrated a marked and sustained reduction in the ARR, regardless of induction and maintenance regimens. EDSS stability was observed, even in patients with active and severe NMOSD.

Safety and efficacy of mycophenolate mofetil in treating neuromyelitis optica spectrum disorders: a protocol for systematic review and meta-analysis

INTRODUCTION

Neuromyelitis optica spectrum disorders (NMOSD) is an inflammatory and heterogeneous astrocyte disorder of the central nervous system with the characteristic of higher incidence in women and Asian people. Most patients with NMOSD have a course of recurrence and remission that is prone to cause paralysis and blindness. Several studies have confirmed the efficacy and promising prospect of mycophenolate mofetil (MMF) in the treatment of NMOSD. Yet its therapeutic effect and safety are controversial. Although there has been two published literature that is relevant to the topic of this study, both of them have certain defects, and they can only provide answers about the efficacy or safety of MMF in the treatment of NMOSD from partial perspectives or conclusions. This research aims to perform a direct and comprehensive systematic review and meta-analysis to evaluate MMF's effectiveness and safety in treating NMOSD.

METHODS AND ANALYSIS

This systematic review will cover all comparative researches, from randomised controlled trials to cohort studies, and case-control study. A relevant literature search will be conducted in PubMed, Web of Science, EMBASE, the Cochrane Library, China National Knowledge Infrastructure, Wanfang Database, China Science and Technology Journal Database and Chinese Biomedical Literature Database from their inception to 31 June 2020. We will also search registers of clinical trials, potential grey literature and abstracts from conferences. There are no limits on language and publication status. The reporting quality and risk of bias will be assessed by two researchers independently. Expanded Disability Status Scales and annualised relapse rate will be evaluated as the primary outcome. The secondary outcomes will consist of the frequency and severity of adverse events, best-corrected visual acuity, relapse-free rate and time to the next attack. A meta-analysis will be performed using RevMan V.5.3 software provided by the Cochrane Collaboration and Stata V.12.0.

ETHICS AND DISSEMINATION

Because the data used for this systematic review will be exclusively extracted from published studies, ethical approval and informed consent of patients will not be required. The systematic review will be published in a peer-reviewed journal, presented at conferences and will be shared on social media platforms.

PROSPERO REGISTRATION NUMBER

CRD42020164179.

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.

The ISCCA flow protocol for the monitoring of anti-CD20 therapies in autoimmune disorders

BACKGROUND

Anti-CD20 monoclonals (MoAbs) are used in a variety of autoimmune disorders. The aim is to eliminate memory B cells sustaining the tissue damage and the production of pathogenic autoantibodies, while preserving naïve cells. The disappearance of memory B cells and the repopulation by naïve cells correlate with good clinical response, while the reappearance of memory B cells and plasmablasts correlates with relapse or resistance to therapy. Anti-CD20 induce extremely low B cell levels, requiring high-resolution techniques. The immune monitoring protocol developed by ISCCA is described and validated, to provide a standardized method for the clinical decision-making process during anti-CD20 therapies in autoimmune diseases.

METHODS

A 10-marker, 8-color staining panel (CD20-V450, CD45-V500c, CD4-FITC + sIgM-FITC, CD38-PE, CD3-PerCP Cy5.5, CD19-PE-Cy7, CD27-APC, CD8-APC H7 + sIgG-APC-H7) is used to identify B cells, plasma cells/blasts, naïve and memory B cells, sIgM+ and sIgG-switched memory B cells, T and NK cells, with high-sensitivity analysis (>10⁶ CD45+ cells).

RESULTS

After an anti-CD20 dose, the B cell level is about zero in most patients. If B cells remain virtually absent (<0.1/μl), subsetting is not reliable nor meaningful. If B cells raise >0.3-0.5/μl, subsetting is possible and informative, acquiring >1.0-1.5 × 10⁶ CD45+ events. Further testings can follow the quality of B cell repopulation. If B cells become detectable (>1/μl), the prevalence of memory B cells indicates non-responsiveness or a possible relapse.

CONCLUSIONS

The ISCCA Protocol is proposed for a standardized prospective monitoring of patients with autoimmune disorders, to assist the safe and rational usage of anti-CD20 therapies.

Pre-pregnancy, obstetric and delivery status in women with neuromyelitis optica spectrum disorder

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a potentially disabling disease which affects predominantly women of reproductive age.

OBJECTIVES

To evaluate the pre-pregnancy condition and to investigate the prevalence of obstetrical and neonatal complaints in NMOSD.

METHODS

An observational retrospective study of 37 NMOSD patients positive for aquaporin-4-immunoglobulin-IgG. Age at menarche, menstrual cycle, gravidity, type of delivery obstetrical complications and perinatal problems were recorded. We assessed the annualized relapse rate (ARR).

RESULTS

A total of 23 patients (62%) suffered from irregular menstruations and two from infertility after disease onset. 11 patients had 20 informative pregnancies with 14 deliveries (5 cesareans) and six abortions, four spontaneous, and two ectopic pregnancies after the first trimester. Additionally, three patients experienced threatening abortion and one preeclampsia. No stillbirth or premature birth was recorded. None of the patients experienced attacks during pregnancy, but postpartum relapses occurred after 10 deliveries (71,4%) with the highest ARR (0.937; p = 0.037) during the first three months postpartum compared to pre-pregnancy ARR (0.375). Four patients (10.8%) developed the initial symptoms of NMOSD postpartum.

CONCLUSION

Irregular menstruation in more than half of NMOSD patients may reflect a hormonal imbalance. Pregnancies were associated with obstetrical complications and increased disease activity postpartum.

Outcome and risk of recurrence in a large cohort of idiopathic longitudinally extensive transverse myelitis without AQP4/MOG antibodies

Background

Longitudinally extensive transverse myelitis (LETM) is classically related to aquaporin (AQP4)-antibodies (Ab) neuromyelitis optica spectrum disorders (NMOSD) or more recently to myelin oligodendrocyte glycoprotein (MOG)-Ab associated disease. However, some patients remain negative for any diagnosis, despite a large work-up including AQP4-Ab and MOG-Ab. Data about natural history, disability outcome, and treatment are limited in this group of patients.

We aimed to (1) describe clinical, biological, and radiological features of double seronegative LETM patients; (2) assess the clinical course and identify prognostic factors; and (3) assess the risk of recurrence, according to maintenance immunosuppressive therapy.

Methods

Retrospective evaluation of patients with a first episode of LETM, tested negative for AQP-Ab and MOG-Ab, from the French nationwide observatory study NOMADMUS.

Results

Fifty-three patients (median age 38 years (range 16–80)) with double seronegative LETM were included. Median nadir EDSS at onset was 6.0 (1–8.5), associated to a median EDSS at last follow-up of 4.0 (0–8). Recurrence was observed in 24.5% of patients in the 18 following months, with a median time to first relapse of 5.7 months. The risk of recurrence was lower in the group of patients treated early with an immunosuppressive drug (2/22, 9%), in comparison with untreated patients (10/31, 32%).

Conclusions

A first episode of a double seronegative LETM is associated to a severe outcome and a high rate of relapse in the following 18 months, suggesting that an early immunosuppressive treatment may be beneficial in that condition.

Real-World Budget Impact of Listing a Biosimilar of Rituximab

BACKGROUND

The approval of new biosimilars by national health agencies is expected to generate significant cost savings for health care systems. This is particularly the case with the biosimilar of rituximab approved for the Canadian market in 2019. However, several uncertainties remain regarding utilization of this agent.

OBJECTIVES

To determine the proportion of total annual drug expenses for each indication for rituximab in the hospital setting and to determine potential savings related to introduction of a biosimilar.

METHODS

A budget impact analysis was performed through 3 real-world scenarios, based on data obtained from a large university teaching hospital for a 12-month period.

RESULTS

This study involved data for 420 patients. Annual expenses for rituximab for all indications represented 7.7% of total annual drug spending for the hospital, of which 5.0% was related specifically to indications approved by Health Canada. More than 6% of the annual drug expenses was attributable to the use of rituximab for oncologic indications, including 1.8% for uses not approved by Health Canada. Overall, each 10% reduction in the price of a biosimilar of rituximab (relative to the reference rituximab) would result in annual savings of about 0.8% of total drug expenses in the hospital if a biosimilar was used for all real-world indications, whether approved by Health Canada or not.

CONCLUSIONS

The introduction of a biosimilar of rituximab to the Canadian market would generate significant savings. To properly assess the potential savings that this agent could generate in the limited budget environment of a hospital, it seems important to consider all of the indications for which it could be used.

A pilot safety study of ublituximab, a monoclonal antibody against CD20, in acute relapses of neuromyelitis optica spectrum disorder

OBJECTIVE

To test the safety of ublituximab, a B cell depleting agent, as add-on therapy in the acute treatment of relapses of neuromyelitis optica spectrum disorder.

METHODS

We conducted an open-label phase 1b safety and proof-of-concept trial in 5 subjects with aquaporin-4 (AQP4)-immunoglobulin G (IgG) seropositive neuromyelitis optica spectrum disorder (NMOSD) who presented with acute transverse myelitis and/or optic neuritis. In addition to treating with 1 g of daily intravenous methylprednisolone, we infused a single dose of 450 mg of ublituximab within 5 days of relapse onset. The primary outcome measure was safety, and the secondary efficacy measures included change in Expanded Disability Status Scale (EDSS), durability of remission and B cell counts.

RESULTS

Five NMOSD subjects were enrolled, 4 of whom presented with acute transverse myelitis and 1 with acute optic neuritis. Ublituximab proved to be safe in all 5 NMOSD subjects, with no serious adverse events recorded. There were no opportunistic infections in any of the subjects; however, 1 subject experienced a transient leukopenia. EDSS scores dropped from a median of 6.5 on admission to 4.0 on 90-day follow up. Two subjects did not achieve total B cell depletion and relapsed within 3 months.

CONCLUSIONS

Ublituximab is a safe add-on therapy for NMOSD patients presenting with acute transverse myelitis and optic neuritis. Preliminary evidence suggests a promising benefit on durability of remission when B cell depletion is achieved. A placebo-controlled trial is necessary to confirm these findings.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that for patients with NMOSD with acute transverse myelitis or optic neuritis, ublituximab is safe and may improve neurological outcome.

Rituximab in neurological disease: principles, evidence and practice

Rituximab is a widely used B-cell-depleting monoclonal antibody. It is unlicensed for use in neurological disorders and there are no treatment guidelines. However, as a rapidly acting, targeted therapy with growing evidence of efficacy and tolerability in several neuroinflammatory disorders, it is an attractive alternative to conventional immunomodulatory medications. This practical review aims to explain the basic principles of B-cell depletion with therapeutic monoclonal antibodies. We present the evidence for using rituximab in neurological diseases, and describe the practical aspects of prescribing, including dosing, monitoring, safety, treatment failure and its use in special circumstances such as coexisting viral hepatitis, pregnancy and lactation. We provide an administration guide, checklist and patient information leaflet, which can be adapted for local use. Finally, we review the safety data of rituximab and ocrelizumab (a newer and recently licensed B-cell-depleting therapy for multiple sclerosis) and suggest monitoring and risk reduction strategies.

Long-term tolerability, safety and efficacy of rituximab in neuromyelitis optica spectrum disorder: a prospective study

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a B-cell-mediated disease with autoimmunity towards the astrocyte water channel aquaporin-4 (AQP-4) in the central nervous system.

OBJECTIVE

To assess the long-term safety and efficacy in NMOSD patients receiving maintenance therapy with B-cell-depleting agent rituximab for more than 2 years.

METHOD

NMOSD patients were included prospectively from 2014 to 2018 and received continuous cycles of rituximab infusions biannually. Incidence of adverse events (AE), serious AEs (SAE), and infusion-related AEs were evaluated through monthly phone calls and neurological examination every 4 months.

RESULTS

A total of 44 NMOSD patients were included, of those 30 were treatment naive (68%). The mean age was 37.2 years with 79.5% females. With overall observation period of 31.6 ± 7.3 months (24-48 months), tolerability was assessed as satisfactory in most cases. We observed infusion reactions (mostly mild) in 31.8% of patients and 31.8% never experienced any AEs after a mean 5.1 cycles of rituximab therapy. Rituximab was also beneficial in terms of improvement in relapse rate (from 0.26 ± 0.54 to 0, P = 0.003) and Expanded Disability Status Scale (from 4.1 ± 1.8 to 3.1 ± 1.8, P < 0.001). Stratification according to AQP4-IgG serostatus showed no difference between groups.

CONCLUSION

Rituximab treatment is well tolerated, safe, and efficacious with a minor risk of mild infusion reactions for NMOSD patients.

Treatment strategies for neuromyelitis optica

Neuromyelitis optica (NMO) is an autoimmune demyelinating disease with pathogenic autoantibodies that act against the astrocyte water channel protein, i.e. aquaporin-4: the disease is associated with recurrent episodes of optic neuritis (ON) and transverse myelitis, often resulting in severe disability. The main goals in treatment of NMO include acute symptomatic therapy and long-term stabilization of symptoms by preventing relapse. In recent years, ongoing randomized controlled trials in NMO patients have studied evidence for treatment. Briefly, acute-stage management (with pulse therapy using corticosteroids and/or plasmapheresis) and maintenance therapy (including rituximab, mycophenolate mofetil, and azathioprine) have been recommended in some case series and retrospective studies. Because of the high prevalence of liver disease, all NMO patients in Taiwan should be screened for hepatitis B and C before treatment is initiated. Although immunosuppression and plasma exchange are the mainstays of therapy for NMO ON, several selective and potentially therapeutic strategies targeting specific steps in NMO pathogenesis including blockers of NMO-IgG binding and inhibitors of granulocyte function have been evaluated in recent years.

Only Follow-Up of Memory B Cells Helps Monitor Rituximab Administration to Patients with Neuromyelitis Optica Spectrum Disorders

Introduction

Neuromyelitis optica spectrum disorders (NMOSD) are identified as a spectrum of inflammatory demyelinating disorders involving the brain, spinal cord and optic nerves. These disorders require early diagnosis and highly active immunosuppressive treatment. Rituximab (RTX) has demonstrated efficacy in limiting relapse in NMOSD when using several administration schedules. We questioned if the CD19+ CD27+ memory B cell count was a more reliable marker to monitor RTX administration than the RTX plasma level and CD19+ B cell count.

Methods

We analyzed 125 blood samples from 17 NMOSD patients treated with RTX and also measured the level of anti-aquaporine-4 antibodies (anti-AQP-4 Abs), human anti-chimeric antibodies to the murine fragment of RTX (HACA-RTX Abs), and the RTX concentration.

Results

The mean follow-up time of the cohort was 7.4 (2–16) years. All patients improved with a mean EDSS going from 4 (1–8.5) to 2.7 (1–5.5). The mean interval between RTX infusions was 9.6 months with identification of prolonged responders. Total CD19+ B cell detection with the routine technique did not correlate to re-emergence of CD19+ CD27+ memory B cells. The RTX residual concentration did not correlate with the CD19+ CD27+ memory B cell count or with anti-RTX antibody production.

Conclusion

In contrast to total CD19+ cell, detected with the routine technique, CD19+ CD27+ memory B cells are a reliable marker for biological relapse and allow a decrease in the frequency of infusions.

Secondary antibody deficiency: a complication of anti-CD20 therapy for neuroinflammation

B-cell depleting anti-CD20 monoclonal antibody therapies are being increasingly used as long-term maintenance therapy for neuroinflammatory disease compared to many non-neurological diseases where they are used as remission-inducing agents. While hypogammaglobulinaemia is known to occur in over half of patients treated with medium to long-term B-cell-depleting therapy (in our cohort IgG 38, IgM 56 and IgA 18%), the risk of infections it poses seems to be under-recognised. Here, we report five cases of serious infections associated with hypogammaglobulinaemia occurring in patients receiving rituximab for neuromyelitis optica spectrum disorders. Sixty-four per cent of the whole cohort of patients studied had hypogammaglobulinemia. We discuss the implications of these cases to the wider use of anti-CD20 therapy in neuroinflammatory disease.

Importance of Regular and Maintenance Therapy Adherence in Neuromyelitis Optica (NMO): Lessons from a Repeating Relapse Case

Patient: Female, 58

Final Diagnosis: NMO

Symptoms: New-onset right leg weakness and pain

Medication: —

Clinical Procedure: Progressive and recurring

Specialty: Neurology

Challenges in the Diagnosis and Treatment of Neuromyelitis Optica Spectrum Disorders: A Case Report With a Brief Review of Literature

Introduction. According to the 2015 diagnostic criteria for neuromyelitis optica spectrum disorders (NMOSD), in aquaporin-4 immunoglobulin G (AQP4-IgG) seronegative patients, NMOSD can be diagnosed if stringent clinical and magnetic resonance imaging (MRI) criteria are fulfilled; however, in these cases, diagnostic and therapeutic challenges could arise. Case Description. A young man presented a severe, bilateral optic neuritis and paraparesis in an acute phase. MRI evidenced 3 spinal cord T1-contrast-enhanced (T1-Gd+) myelitic lesions, extending <3 vertebral segments. AQP4-IgG and oligoclonal bands were negative. Following a relapse, MRI showed 2 T1-Gd+ spinal cord lesions, extending <3 vertebral segments, and a T1-Gd+ lesion in both optic nerves, near their confluence in the chiasm. After administering rituximab, there were no new relapses, with the consequent improvement of the clinical and MRI lesions. Conclusion. The concurrent display of bilateral optic neuritis and short myelitis constitutes a “borderline” case. Rituximab may represent the most appropriate therapeutic choice possible cases of NMOSD.

Diagnosis and management of Neuromyelitis Optica Spectrum Disorder (NMOSD) in Iran: A consensus guideline and recommendations

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a relapsing neuro inflammatory disease of the central nervous system that typically presents with optic neuritis or myelitis and may cause severe disability. The diagnostic criteria have been updated and several immunosuppressive agents have been demonstrated to prevent acute exacerbations. As the disease rarely develops in a progressive course, management of acute attacks and proper prevention of exacerbations may change the long term out-come and prevent future disability. Consensus recommendations and guidelines will help the physicians to improve their practice and unify the treatment approaches in different communities. In order to develop a national consensus and recommendations for the diagnosis and management of NMOSD in Iran, a group of neurologists with long term experience in management of NMOSD were gathered to develop this consensus based on available national and international data. The primary draft was prepared and discussed to suggest the most appropriate treatment for these patients. We propose strategies for early diagnosis and treatment for prevention of relapses and minimizing consequences of attacks as a primary therapeutic goal. Attacks are currently treated with intravenous corticosteroids and, in refractory cases, with plasma exchange. All participants agreed on preventive treatment with currently available immunosuppressive agents such as azothioprin, rituximab and mycofenolate mofetil based on previous positive data in NMOSD in order to reduce attack frequency. The current consensus reviews the previous data and provides the clinicians with practical recommendations and advices for the diagnosis and management of NMOSD based on scientific data and clinical experience.

Neuromyelitis Optica

Neuromyelitis optica (NMO), formerly known as Devic disease, is an autoimmune astrocytopathic disease characterized by transverse myelitis and optic neuritis. Most patients demonstrate a relapsing course with incomplete recovery between attacks, resulting in progressive disability. The pathogenesis involves production of aquaporin-4 antibodies (AQP4-IgG) by plasmablasts in peripheral circulation, disruption of the blood-brain barrier, complement-mediated astrocyte injury, and secondary demyelination. The diagnosis relies on characteristic clinical manifestations in the presence of serum AQP4-IgG positivity or specific neuroimaging findings, and exclusion of alternative etiologies. Current treatment involves aggressive immunosuppression with pulse-dose steroids during acute attacks and long-term immunosuppression for attack prevention.

Capillary leak syndrome in neuromyelitis optica treated with rituximab

61-year-old woman with Neuromyelitis optica (NMO) diagnosis treated with rituximab was referred to our hospital with severe hypovolemic shock and anasarca. The laboratory findings showed marked hemoconcentration and a decrease in total serum protein. She developed a multiple organ failure and died three hours later. We diagnosed the patient as having capillary leak syndrome (CLS). CLS is a very rare condition caused by unexplained episodic capillary hyperpermeability, which can be idiopathic or secondary to some conditions like infection, malignant disease and some drugs like monoclonal antibodies. We reported the first CLS case in NMO patient treated with rituximab.

The Rituximab Biosimilar CT-P10 in Rheumatology and Cancer: A Budget Impact Analysis in 28 European Countries

Introduction

New biosimilars of monoclonal antibodies are anticipated to bring significant cost savings and increase access to treatment. The rituximab biosimilar CT-P10 has recently been approved in Europe in all indications held by reference rituximab (RTX), including rheumatoid arthritis, non-Hodgkin’s lymphoma, and chronic lymphocytic leukemia. We analyzed the budgetary impact of the introduction of CT-P10 into the European Union (EU) for use in patients with rheumatoid arthritis and cancer diagnoses, using a budget impact analysis model.

Methods

The model used a base case scenario in which the 1-year uptake of CT-P10 was estimated at 30%, and the cost of CT-P10 was assumed to be 70% of the cost of RTX. A second 1-year scenario was also modeled, in which the market share of CT-P10 was assumed to be 50% (scenario 2). Finally, 3-year time horizon outcomes were calculated, in which the market share of CT-P10 was assumed to be 30%, 40%, and 50% in the first, second, and third years, respectively.

Results

In the base case scenario, the introduction of CT-P10 was associated with projected savings of €90.04 million in the first year, which would allow 7531 additional patients to access rituximab treatment. This was equivalent to a 6.4% increase in the number of rituximab-treated patients. In scenario 2, budget savings were €150.10 million, with a total of 12,551 additional patients able to access rituximab, equivalent to a 10.7% increase. Over a 3-year time horizon, projected budget savings were approximately €570 million, equating to 47,695 additional patients able to access rituximab.

Conclusions

The model predicted that the introduction of CT-P10 in the EU will be associated with significant budget savings, the reallocation of which will enable many more patients to access rituximab treatment. This is likely to have a significant impact on health gains at patient and societal levels.

Funding: CELLTRION Healthcare Co., Ltd. sponsored the development and analysis of the budget impact analysis model.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-017-0522-y) contains supplementary material, which is available to authorized users.

Treating primary-progressive multiple sclerosis: potential of ocrelizumab and review of B-cell therapies

Multiple sclerosis (MS) therapy has evolved rapidly with an increased availability of several immunomodulating therapies over the past two decades. Disease-modifying therapies have proven to be effective in treating relapse-remitting MS (RRMS). However, clinical trials involving some of the same agents for secondary-progressive and primary-progressive MS (SPMS and PPMS) have been largely negative. The pathogenesis of progressive MS remains unclear, but B-cells may play a significant role in chronic compartmentalized inflammation, likely contributing to disease progression. Biologics targeted at B-cells, such as rituximab, are effective in treating RRMS. Ocrelizumab is a humanized monoclonal antibody to CD20+ B-cells that has shown positive results in PPMS with a significant reduction in disease progression. This review aims to discuss in detail the involvement of B-cells in MS pathogenesis, current progress of currently available and investigational biologics, with focus on ocrelizumab, and future prospects for B-cell therapy in PPMS.

Monitoring CD27+ memory B-cells in neuromyelitis optica spectrum disorders patients treated with rituximab: Results from a bicentric study

BACKGROUND

Rituximab (RTX) is increasingly used in the treatment of neuromyelitis optica spectrum disorder (NMO-SD). Administration regimen is not consensual as there is no reliable biomarker of RTX efficacy. In most cases, after induction, RTX is administered systematically every 6months.

OBJECTIVE

To assess efficacy and safety of a maintenance regimen based on CD19+ CD27+ memory B-cell (mBc) detection.

METHODS

We conducted a study in two French centers, including patients with NMO-SD who received an induction therapy with RTX. We compared the number of administered infusions, relapses and EDSS depending on two maintenance schemes (S1: administration of 1g RTX infusion every 6months or S2: a scheme based on regular mBc detection. 1g RTX was administered if mBc was >0.05%) RESULTS: 40 patients were included (mean age: 40.2years, F/M sex ratio: 5/1). Aquaporin-4 antibodies were positive in 75% patients. Under S1 regimen, all patients received 2 infusions per year, whereas under S2, they received 1.62 infusion per year. The mean interval between infusions under S2 was 7.4months, without decrease of clinical efficacy.

CONCLUSION

In our study, mBc-based administration of RTX allowed personalizing treatment administration and in several cases to lower the cumulative dose without loss of efficacy.

Aquaporin-4 antibody titration in NMO patients treated with rituximab: A retrospective study

Objective:

We undertook an observational retrospective study to investigate the usefulness of aquaporin-4 (AQP4) antibodies (Ab) titration in the management of patients with neuromyelitis optica (NMO) treated with rituximab (RTX) by studying (1) the correlation between AQP4-Ab titer and disease activity, (2) the influence of RTX on antibody levels, and (3) the association between AQP4-Ab levels and responsiveness to RTX.

Methods:

A cell-based assay was used for AQP4-Ab titration in 322 serum samples from 7 patients with NMO treated with RTX (median follow-up 65 months), according to a treatment-to-target approach. Serum samples were collected every month following standardized procedures.

Results:

(1) In group analysis, AQP4-Ab titers correlated with the disease activity, showing higher titers during and preceding relapses than during remission. However, in individual analysis, an increase in AQP4-Ab titers and CD19+ B cells did not always precede a relapse. (2) A reduction of AQP4-Ab titers in the short-term and long-term period was observed during RTX treatment. (3) Reduction of AQP4-Ab titers was observed in responder patients both 3 months after RTX infusion and in the long-term follow-up. In one nonresponder patient, AQP4-Ab levels never decreased during the treatment period.

Conclusions:

Titration of AQP4-Abs could be useful in the clinical management of patients with NMO treated with RTX: titration before each reinfusion and 3 months after each reinfusion may provide information about responsiveness to RTX. Although a relationship among AQP4-Ab levels, disease activity, and response to RTX was observed, the usefulness of AQP4-Ab titration to predict relapses is limited.

Treatment of neuromyelitis optica and neuromyelitis optica spectrum disorders with rituximab using a maintenance treatment regimen and close CD19 B cell monitoring. A six-year follow-up

Neuromyelitis optinca (NMO) represents a serious demyelinating disease of the central nervous system selectively attacking the spinal cord and optic nerve. Early differential diagnosis from multiple sclerosis is of vital importance, as NMO mandates immunosuppressive and not immunomodulatory treatment. Rituximab has been recently introduced as a treatment option for NMO. However, optimal surrogate measures and treatment intervals are still unclear. Five patients (females, mean age 54±10.21years) with NMO and NMO spectrum disorders (NMOSD) were evaluated with respect to disability and relapse rate. All patients were found positive for NMO IgG. All patients (three with NMO and two with NMOSD, 1 patient with recurrent optic neuritis and 1 patient with recurrent myelitis) had received rituximab treatment for six years. One patient with NMOSD received cyclophosphamide prior to rituximab while two were misdiagnosed as multiple sclerosis and had received interferon treatment. All received rituximab infusion of 375mg/m² once per week for 4weeks and then every two months for the first two years and then every six months. B-cell counts were measured every two months and were kept in almost undetectable levels. No relapse was noted during the treatment period while EDSS score was improved in all patients. No severe adverse effects occurred during RTX treatment. Rituximab treatment on NMO and NMOSD patients showed significant improvement in disability and relapse-rate without any significant adverse effects.