Secondary hypogammaglobulinemia in patients with multiple sclerosis on anti-CD20 therapy: Pathogenesis, risk of infection, and disease management.

Hypogammaglobulinemia is characterized by reduced serum immunoglobulin levels. Secondary hypogammaglobulinemia is of considerable interest to the practicing physician because it is a potential complication of some medications and may predispose patients to serious infections. Patients with multiple sclerosis (MS) treated with B-cell-depleting anti-CD20 therapies are particularly at risk of developing hypogammaglobulinemia. Among these patients, hypogammaglobulinemia has been associated with an increased risk of infections. The mechanism by which hypogammaglobulinemia arises with anti-CD20 therapies (ocrelizumab, ofatumumab, ublituximab, rituximab) remains unclear and does not appear to be simply due to the reduction in circulating B-cell levels. Further, despite the association between anti-CD20 therapies, hypogammaglobulinemia, and infections, there is currently no generally accepted monitoring and treatment approach among clinicians treating patients with MS. Here, we review the literature and discuss possible mechanisms of secondary hypogammaglobulinemia in patients with MS, hypogammaglobulinemia results in MS anti-CD20 therapy clinical trials, the risk of infection for patients with hypogammaglobulinemia, and possible strategies for disease management. We also include a suggested best-practice approach to specifically address secondary hypogammaglobulinemia in patients with MS treated with anti-CD20 therapies.

Bruton's Tyrosine Kinase Inhibitors: The Next Frontier of B-Cell-Targeted Therapies for Cancer, Autoimmune Disorders, and Multiple Sclerosis.

Bruton's tyrosine kinase (BTK) is an important protein belonging to the tyrosine kinase family that plays a key role in the intracellular signaling and proliferation, migration, and survival of normal and malignant B-lymphocytes and myeloid cells. Understanding the role of BTK in the B-cell signaling pathway has led to the development of BTK inhibitors (BTKi) as effective therapies for malignancies of myeloid origin and exploration as a promising therapeutic option for other cancers. Given its central function in B-cell receptor signaling, inhibition of BTK is an attractive approach for the treatment of a wide variety of autoimmune diseases that involve aberrant B-cell function including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and multiple sclerosis (MS). Here, we review the role of BTK in different cell signaling pathways, the development of BTKi in B-cell malignancies, and their emerging role in the treatment of MS and other autoimmune disorders.

Peripheral nervous system electrodiagnostic abnormalities in predominantly Hispanic Multiple Sclerosis patients.

BACKGROUND: Peripheral nervous system (PNS) abnormalities in Multiple Sclerosis (MS) have been reported in case reports and small case series over the past several decades. Little is known, however, about the prevalence of electrodiagnostic abnormalities in patients with MS, including not only demyelinating neuropathies such as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) but also axonal peripheral neuropathy and sympathetic dysfunction. METHODS: This is an observational, cross-sectional study with the objective of identifying the prevalence of the electrodiagnostic abnormalities in predominantly Hispanic MS patients in Miami, Florida. Electrodiagnostic data including nerve conduction study (NCS), electromyography (EMG) and sympathetic skin response (SSR) information was prospectively collected in 18 patients (16 females; 43.7±15.2 years) with a diagnosis of MS compared to 18 healthy (16 females; 39.9±11 years), age- and height-matched controls. The study was offered to all-comers in the MS Clinic over a period of 3 months, regardless of clinical suspicion for an underlying neuropathic process, in an effort to estimate the prevalence of abnormalities. Demographic data including age, sex, race/ethnicity was evaluated in addition to MS-specific characteristics including MS subtype, duration of disease, duration of therapy, clinical symptoms and laboratory data. RESULTS: There were no significant differences in baseline characteristics of patients and controls for age (p=0.4) and height (164.0±6.4 vs 162.3±4.6 centimeters; p=0.3). The mean disease duration was 106±27 months (median 107 months; range 5-336 months). The mean Expanded Disability Status Scale (EDSS) was 2.4±1.87 (median: 2.5; range 1.0-6.5). The ethnicity of patients (15 Hispanic, 3 non-Hispanic) and controls (13 Hispanic, 5 non-Hispanic; p=0.56) was similar. The frequency of electrophysiological axonal polyneuropathy (PN) was 77.8% (14/18 patients), and 85.6% of these patients had clinical sensory symptoms. Interestingly, 1 patient had previously unrecognized CIDP. All 18 patients displayed prolonged SSR latencies consistent with autonomic dysfunction. Thirteen patients (72.2%) reported autonomic symptoms such as bladder abnormalities and blood pressure fluctuations. CONCLUSION: The prevalence of electrodiagnostic abnormalities, especially axonal polyneuropathy, in the MS population may be higher than traditionally considered. The relationship between axonal polyneuropathy and central axonopathy in the context of neurodegeneration in MS should be further explored. Analytic studies may identify common symptomatic and pathophysiologic etiologies to further understanding and potentially guide treatment of MS subtypes with PNS involvement.

COVID-19 in Patients With Neuromyelitis Optica Spectrum Disorders and Myelin Oligodendrocyte Glycoprotein Antibody Disease in North America: From the COViMS Registry.

BACKGROUND AND OBJECTIVE: To describe the impact of coronavirus disease 2019 (COVID-19) on people with neuromyelitis optica spectrum disorders (NMOSD) and myelin oligodendrocyte glycoprotein antibody disease (MOGAD). METHODS: The COVID-19 Infections in Multiple Sclerosis (MS) and Related Diseases (COViMS) Registry collected data on North American patients with MS and related diseases with laboratory-positive or highly suspected SARS-CoV-2 infection. Deidentified data were entered into a web-based registry by health care providers. Data were analyzed using t-tests, Pearson χ2 tests, or Fisher exact tests for categorical variables. Univariate logistic regression models examined effects of risk factors and COVID-19 clinical severity. RESULTS: As of June 7, 2021, 77 patients with NMOSD and 20 patients with MOGAD were reported in the COViMS Registry. Most patients with NMOSD were laboratory positive for SARS-CoV-2 and taking rituximab at the time of COVID-19 diagnosis. Most patients with NMOSD were not hospitalized (64.9% [95% CI: 53.2%-75.5%]), whereas 15.6% (95% CI: 8.3%-25.6%) were hospitalized only, 9.1% (95% CI: 3.7%-17.8%) were admitted to the ICU and/or ventilated, and 10.4% (95% CI: 4.6%-19.5%) died. In patients with NMOSD, having a comorbidity was the sole factor identified for poorer COVID-19 outcome (OR = 6.0, 95% CI: 1.79-19.98). Most patients with MOGAD were laboratory positive for SARS-CoV-2, and almost half were taking rituximab. Among patients with MOGAD, 75.0% were not hospitalized, and no deaths were recorded; no factors were different between those not hospitalized and those hospitalized, admitted to the ICU, or ventilated. DISCUSSION: Among the reported patients with NMOSD, a high mortality rate was observed, and the presence of comorbid conditions was associated with worse COVID-19 outcome. There were no deaths reported in the patients with MOGAD, although these observations are limited due to small sample size.

Expert Perspectives on COVID-19 Vaccination for People Living with Multiple Sclerosis.

COVID-19 vaccines are safe for people living with MS on or off disease-modifying therapies and are important for the prevention of COVID-19. Antibody responses for individuals on certain DMTs may be diminished, however, T-cell responses may be preserved in those individuals. Data are lacking regarding optimal timing of vaccinations, and delaying disease-modifying therapies may increase the risk of disease activity and progression. In this perspective podcast, the authors recommend COVID-19 vaccination as soon as possible, regardless of timing considerations, in most cases.

Longitudinal Study of Retinal Structure, Vascular, and Neuronal Function in Patients With Relapsing-Remitting Multiple Sclerosis: 1-Year Follow-Up.

Objective: The purpose of this study was to quantify retinal structural, vascular, and functional changes in patients with relapsing-remitting multiple sclerosis (RRMS) over 1 year. Methods: Eighty-eight eyes of 44 patients with RRMS underwent assessments of low contrast letter acuity (LCLA), retinal ganglion cell function detected by the steady-state pattern electroretinogram (PERG), axonal microstructural integrity measured as birefringence, intraretinal layer thicknesses by ultra-high-resolution optical coherence tomography (OCT), volumetric vessel density (VVD) by OCT angiography, and retinal tissue perfusion (RTP) by the Retinal Function Imager (RFI). All measurements were performed at baseline and 1-year follow-up. The impacts of disease activities and a history of optic neuritis (ON) were analyzed. Results: Compared to baseline, there were no significant differences in all variables (P > 0.05), except for the axonal birefringence and RTP. The birefringence's of the retinal fiber layer at the temporal and superior quadrants was significantly decreased (P < 0.05), whereas RTP was significantly increased (P < 0.05). In the subgroup with ON, significantly longer PERG latency and decreased VVD were observed at follow-up (P < 0.05). In patients with improved LCLA, significantly increased RTP and decreased VVD (P < 0.05) were also observed. Conclusions: This is the first longitudinal study that assessed the RTP and VVD, along with other retinal structural and functional parameters in MS. The recovery of retinal vascular function occurred with the improved LCLA, suggesting that these measurements may be associated with disease progression. Translational Relevance: The retinal microvascular changes could be potential biomarkers for monitoring therapeutic efficacy in MS.

The North American Registry for Care and Research in Multiple Sclerosis (NARCRMS).

Although many regional multiple sclerosis (MS) databases existed in the United States and Canada, there was no single clinician-derived registry that examined this disease as a group across the North American continent. This distinction is important because information that results from such a database can potentially give perspectives about MS that cannot be derived from any single regional registry. A partnership was forged between the pharmaceutical industry and the Consortium of Multiple Sclerosis Centers (CMSC) to create a registry of patients with MS from Canada and the United States, including Puerto Rico. Case report forms were created to collect physician-derived information, and the Patient-Reported Outcomes Measurement Information System (PROMIS) was selected to capture patient-reported outcomes. As of November 2021, 754 of 1000 patients have been enrolled. Completion of recruitment is expected by the end of 2021. Twenty-five centers are participating, with an expected total of 30, including five centers from Canada. Clinical status, health economic outcomes, magnetic resonance images, and, soon, biomarkers relevant to understanding relapses and progression are collected. The short-term goal is to understand and better treat MS disease progression, and the long-term goal is its prevention. The North American Registry for Care and Research in Multiple Sclerosis (NARCRMS) is one of few clinician/patient-generated registries that examines MS across North America, including Puerto Rico. Information derived from the natural history studies should help physicians, the pharmaceutical industry, and regulatory bodies understand MS better and improve quality of life for patients with MS worldwide.

Efficacy of Cladribine Tablets in high disease activity subgroups of patients with relapsing multiple sclerosis: A post hoc analysis of the CLARITY study.

BACKGROUND: In the CLARITY (CLAdRIbine Tablets treating multiple sclerosis orallY) study, Cladribine Tablets significantly improved clinical and magnetic resonance imaging (MRI) outcomes (vs placebo) in patients with relapsing-remitting multiple sclerosis. OBJECTIVE: Describe two clinically relevant definitions for patients with high disease activity (HDA) at baseline of the CLARITY study (utility verified in patients receiving placebo) and assess the treatment effects of Cladribine Tablets 3.5 mg/kg compared with the overall study population. METHODS: Outcomes of patients randomised to Cladribine Tablets 3.5 mg/kg or placebo were analysed for subgroups using HDA definitions based on high relapse activity (HRA; patients with ⩾2 relapses during the year prior to study entry, whether on DMD treatment or not) or HRA plus disease activity on treatment (HRA + DAT; patients with ⩾2 relapses during the year prior to study entry, whether on DMD treatment or not, PLUS patients with ⩾1 relapse during the year prior to study entry while on therapy with other DMDs and ⩾1 T1 Gd+ or ⩾9 T2 lesions). RESULTS: In the overall population, Cladribine Tablets 3.5 mg/kg reduced the risk of 6-month-confirmed Expanded Disability Status Scale (EDSS) worsening by 47% vs placebo. A risk reduction of 82% vs placebo was seen in both the HRA and HRA + DAT subgroups (vs 19% for non-HRA and 18% for non-HRA + DAT), indicating greater responsiveness to Cladribine Tablets 3.5 mg/kg in patients with HDA. There were consistent results for other efficacy endpoints. The safety profile in HDA patients was consistent with the overall CLARITY population. CONCLUSION: Patients with HDA showed clinical and MRI responses to Cladribine Tablets 3.5 mg/kg that were generally better than, or at least comparable with, the outcomes seen in the overall CLARITY population.

Ocrelizumab versus Interferon Beta-1a in Relapsing Multiple Sclerosis.

BACKGROUND: B cells influence the pathogenesis of multiple sclerosis. Ocrelizumab is a humanized monoclonal antibody that selectively depletes CD20+ B cells. METHODS: In two identical phase 3 trials, we randomly assigned 821 and 835 patients with relapsing multiple sclerosis to receive intravenous ocrelizumab at a dose of 600 mg every 24 weeks or subcutaneous interferon beta-1a at a dose of 44 µg three times weekly for 96 weeks. The primary end point was the annualized relapse rate. RESULTS: The annualized relapse rate was lower with ocrelizumab than with interferon beta-1a in trial 1 (0.16 vs. 0.29; 46% lower rate with ocrelizumab; P<0.001) and in trial 2 (0.16 vs. 0.29; 47% lower rate; P<0.001). In prespecified pooled analyses, the percentage of patients with disability progression confirmed at 12 weeks was significantly lower with ocrelizumab than with interferon beta-1a (9.1% vs. 13.6%; hazard ratio, 0.60; 95% confidence interval [CI], 0.45 to 0.81; P<0.001), as was the percentage of patients with disability progression confirmed at 24 weeks (6.9% vs. 10.5%; hazard ratio, 0.60; 95% CI, 0.43 to 0.84; P=0.003). The mean number of gadolinium-enhancing lesions per T1-weighted magnetic resonance scan was 0.02 with ocrelizumab versus 0.29 with interferon beta-1a in trial 1 (94% lower number of lesions with ocrelizumab, P<0.001) and 0.02 versus 0.42 in trial 2 (95% lower number of lesions, P<0.001). The change in the Multiple Sclerosis Functional Composite score (a composite measure of walking speed, upper-limb movements, and cognition; for this z score, negative values indicate worsening and positive values indicate improvement) significantly favored ocrelizumab over interferon beta-1a in trial 2 (0.28 vs. 0.17, P=0.004) but not in trial 1 (0.21 vs. 0.17, P=0.33). Infusion-related reactions occurred in 34.3% of the patients treated with ocrelizumab. Serious infection occurred in 1.3% of the patients treated with ocrelizumab and in 2.9% of those treated with interferon beta-1a. Neoplasms occurred in 0.5% of the patients treated with ocrelizumab and in 0.2% of those treated with interferon beta-1a. CONCLUSIONS: Among patients with relapsing multiple sclerosis, ocrelizumab was associated with lower rates of disease activity and progression than interferon beta-1a over a period of 96 weeks. Larger and longer studies of the safety of ocrelizumab are required. (Funded by F. Hoffmann-La Roche; OPERA I and II ClinicalTrials.gov numbers, NCT01247324 and NCT01412333 , respectively.).

Ocrelizumab versus Placebo in Primary Progressive Multiple Sclerosis.

BACKGROUND: An evolving understanding of the immunopathogenesis of multiple sclerosis suggests that depleting B cells could be useful for treatment. We studied ocrelizumab, a humanized monoclonal antibody that selectively depletes CD20-expressing B cells, in the primary progressive form of the disease. METHODS: In this phase 3 trial, we randomly assigned 732 patients with primary progressive multiple sclerosis in a 2:1 ratio to receive intravenous ocrelizumab (600 mg) or placebo every 24 weeks for at least 120 weeks and until a prespecified number of confirmed disability progression events had occurred. The primary end point was the percentage of patients with disability progression confirmed at 12 weeks in a time-to-event analysis. RESULTS: The percentage of patients with 12-week confirmed disability progression was 32.9% with ocrelizumab versus 39.3% with placebo (hazard ratio, 0.76; 95% confidence interval [CI], 0.59 to 0.98; P=0.03). The percentage of patients with 24-week confirmed disability progression was 29.6% with ocrelizumab versus 35.7% with placebo (hazard ratio, 0.75; 95% CI, 0.58 to 0.98; P=0.04). By week 120, performance on the timed 25-foot walk worsened by 38.9% with ocrelizumab versus 55.1% with placebo (P=0.04); the total volume of brain lesions on T2-weighted magnetic resonance imaging (MRI) decreased by 3.4% with ocrelizumab and increased by 7.4% with placebo (P<0.001); and the percentage of brain-volume loss was 0.90% with ocrelizumab versus 1.09% with placebo (P=0.02). There was no significant difference in the change in the Physical Component Summary score of the 36-Item Short-Form Health Survey. Infusion-related reactions, upper respiratory tract infections, and oral herpes infections were more frequent with ocrelizumab than with placebo. Neoplasms occurred in 2.3% of patients who received ocrelizumab and in 0.8% of patients who received placebo; there was no clinically significant difference between groups in the rates of serious adverse events and serious infections. CONCLUSIONS: Among patients with primary progressive multiple sclerosis, ocrelizumab was associated with lower rates of clinical and MRI progression than placebo. Extended observation is required to determine the long-term safety and efficacy of ocrelizumab. (Funded by F. Hoffmann-La Roche; ORATORIO ClinicalTrials.gov number, NCT01194570 .).