Emerging drugs for the acute treatment of relapses in adult neuromyelitis optica spectrum disorder patients

Treatment strategies and responses for attacks of neuromyelitis optica spectrum disorder: A real-world retrospective cohort study

We aimed to assess the treatment strategies utilized in patients with neuromyelitis optica spectrum disorder (NMOSD) experiencing relapses, including their frequency, types, and response after 6 months based on the Expanded Disability Status Scale (EDSS) score.

METHODS

We conducted a retrospective study involving NMOSD patients from the Argentinean MS and NMOSD registry (RelevarEM, NCT03375177). Treatment response at 6 months was categorized as "good" if the EDSS score decreased by ≥1 point after a nadir EDSS score ≤ 3, or by ≥2 points after a nadir EDSS score > 3, "poor" if the EDSS score decrease was slighter, and as "absent" if the EDSS score remained unchanged or worsened.

RESULTS

We included 120 NMOSD patients (seropositive N = 75), who experienced 250 NMOSD-related relapses and received 248 treatments. At 6 months, complete recovery was achieved in 70/98 (71.4%) and 15/19 (79%) patients, respectively. Predictors of a "good" response in our regression model were a younger age at disease onset (OR:3.54, CI95% 2.45-5.01, p < 0.0001) and a short delay from onset of relapse to treatment initiation (OR:1.56, CI95% 1.22-2.13, p = 0.004).

CONCLUSIONS

Approximately two-thirds of patients experienced complete recovery, and younger age and a short delay to start treatment were independent predictors of a "good" response.

Moving towards a new era for the treatment of neuromyelitis optica spectrum disorders

Neuromyelitis optica spectrum disorders (NMOSD) include a rare group of autoimmune conditions that primarily affect the central nervous system. They are characterized by inflammation and damage to the optic nerves, brain and spinal cord, leading to severe vision impairment, locomotor disability and sphynteric disturbances. In the majority of cases, NMOSD arises due to specific serum immunoglobulin G (IgG) autoantibodies targeting aquaporin 4 (AQP4-IgG), which is the most prevalent water-channel protein of the central nervous system. Early diagnosis and treatment are crucial to manage symptoms and prevent long-term disability in NMOSD patients. NMOSD were previously associated with a poor prognosis. However, recently, a number of randomized controlled trials have demonstrated that biological therapies acting on key elements of NMOSD pathogenesis, such as B cells, interleukin-6 (IL-6) pathway, and complement, have impressive efficacy in preventing the occurrence of clinical relapses. The approval of the initial drugs marks a revolutionary advancement in the treatment of NMOSD patients, significantly transforming therapeutic options and positively impacting their prognosis. In this review, we will provide an updated overview of the key immunopathological, clinical, laboratory, and neuroimaging aspects of NMOSD. Additionally, we will critically examine the latest advancements in NMOSD treatment approaches. Lastly, we will discuss key aspects regarding optimization of treatment strategies and their monitoring.

NMOSD IgG Impact Retinal Cells in Murine Retinal Explants

Neuromyelitis optica spectrum disorders (NMOSD) are chronic inflammatory diseases of the central nervous system, characterized by autoantibodies against aquaporin-4. The symptoms primarily involve severe optic neuritis and longitudinally extensive transverse myelitis. Although the disease progression is typically relapse-dependent, recent studies revealed retinal neuroaxonal degeneration unrelated to relapse activity, potentially due to anti-aquaporin-4-positive antibodies interacting with retinal glial cells such as Müller cells. In this exploratory study, we analysed the response of mouse retinal explants to NMOSD immunoglobulins (IgG). Mouse retinal explants were treated with purified IgG from patient or control sera for one and three days. We characterized tissue response patterns through morphological changes, chemokine secretion, and complement expression. Mouse retinal explants exhibited a basic proinflammatory response ex vivo, modified by IgG addition. NMOSD IgG, unlike control IgG, increased gliosis and decreased chemokine release (CCL2, CCL3, CCL4, and CXCL-10). Complement component expression by retinal cells remained unaltered by either IgG fraction. We conclude that human NMOSD IgG can possibly bind in the mouse retina, altering the local cellular environment. This intraretinal stress may contribute to retinal degeneration independent of relapse activity in NMOSD, suggesting a primary retinopathy.

Factors associated with disease relapse rate in the Neuromyelitis optica spectrum disorder

BACKGROUND AND OBJECTIVES

Neuromyelitis optica spectrum disorder (NMOSD) is a group of demyelinating diseases of the nervous system with high relapse rate and high disability rate without treatment, and we aimed to explore the influencing factors related to the recurrence of NMOSD and provide basis for clinical treatment in this study.

METHODS

Referring to the diagnostic criteria for NMOSD issued in 2015, 259 patients were enrolled. Clinical information, cerebrospinal fluid (CSF) and serum analysis results, brain and spinal cord magnetic resonance imaging (MRI) findings, treatment details, and prognosis were all recorded.

RESULTS

176 (68.00%) participants were found to be AQP4 Ab-positive in serum or CSF, and the relapse rate was 36.67% (95/259). These 259 individuals were separated into two groups: non-release (n = 164) and relapse (n = 95). In terms of EDSS scores at onset, EDSS score after treatment, lesion location, serum creatinine (Cr) and treatment strategy, there were statistical differences between the two groups. Multivariable logistic regression analyses revealed five predictors for recurrence of NMOSD patients within two years: EDSS scores at onset, transverse myelitis, brain/brainstem, Cr, and Rituximab/immunosuppressants.

CONCLUSION

It is essential to explore the risk factors related to recurrence and prevent them to reduce the risk of disability and improve the prognosis, and the recurrence rate of NMOSD may be affected by several factors.

Barriers to access and unmet needs to neuromyelitis optica spectrum disorders care in an Argentinean cohort

INTRODUCTION

Neuromyelitis optica spectrum disorder (NMOSD) is a rare but severe neuroimmunological condition associated with a significant financial burden. NMOSD is also associated with increased health care utilization, including neurology outpatient visits, magnetic resonance imaging (MRI) use, long-term medication, among others. We aimed to evaluate real-world patient experiences in access to care and NMOSD burden in an Argentinean cohort.

METHODS

This cross-sectional study used a self-administered survey and was conducted in Argentina (2022). Patients with NMOSD were divided into three groups: private health insurance (PHI), social health insurance (SHI), and public health insurance (PHI, Ministry of Public Health). Differences in access and health care barriers were assessed.

RESULTS

One hundred patients with NMOSD (74 women) with a mean age at diagnosis of 38.7 years were included. Their EDSS was 2.8 and they were followed for 5.2 years. Of them, 51%, 11%, and 13% were employed (full-time: 57.5%), currently unemployed and retired by NMOSD, respectively. 55% of them visited between 2-3 specialists before NMOSD diagnosis. Aquaporin-4-antibody and/or myelin oligodendrocyte glycoprotein-antibody testing was requested in 91% (health insurance covered this partially in 15.3% and 32.9% of the time the test was entirely paid by patient/family). Patients with NMOSD receiving private medical care reported greater access to MRI, outpatient visits, and fewer issues to obtain NMOSD medications compared to those treated at public institutions. A longer mean time to MRI and neurology visit was found in the PHI group when compared with the other two subgroups. Regression analysis showed that private insurance (OR=3.84, p=0.01) was the only independent factor associated with appropriate access to NMOSD medications in Argentina.

CONCLUSION

These findings suggest that barriers to access and utilization of NMOSD care services in Argentina are common. NMOSD patients experienced problems to receive NMOSD medication properly, especially those from the public sector.

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.