Efficacy and Safety of Inebilizumab in IgG4-Related Disease: Protocol for a Randomized Controlled Trial

INTRODUCTION

Immunoglobulin G4-related disease (IgG4-RD) is a debilitating multiorgan disease characterized by recurring flares leading to organ dysfunction, decreased quality of life, and mortality. Glucocorticoids, the standard of care for IgG4-RD, are associated with substantial treatment-related toxicity. Inebilizumab, an antibody directed against CD19, mediates the rapid and durable depletion of CD19+ B cells thought to be involved in IgG4-RD pathogenesis. We describe the first international, prospective, double-blind, placebo-controlled trial to evaluate the safety and efficacy of B-cell depletion for flare prevention in IgG4-RD (MITIGATE).

METHODS

The study was designed by an international panel of physicians with expertise in IgG4-RD. Critical trial design decisions included the selection of participants, definition of clinically meaningful primary and secondary endpoints, accommodation of standard of care, and development of flare diagnostic criteria. The study is approved for conduct in 22 countries.

PLANNED OUTCOMES

The primary efficacy endpoint is time from randomization to the occurrence of the first centrally adjudicated and investigator-treated disease flare during the 1-year randomized controlled period. A set of novel, organ-specific flare diagnostic criteria were developed specifically for this trial, incorporating symptoms and signs, laboratory findings, imaging study results, and pathology data. MITIGATE aims to accrue 39 flares for the primary endpoint, which provides sufficient power to detect a relative risk reduction of 65% in the inebilizumab group. It is anticipated that enrollment of 160 participants will achieve this goal. Additional endpoints include safety, annualized flare rate, flare-free complete remission, quality-of-life measures, and cumulative glucocorticoid use. MITIGATE represents the first randomized, double-blind, placebo-controlled trial of any treatment strategy conducted in IgG4-RD. Data from this study will provide insights into the natural history and pathophysiology of IgG4-RD and the efficacy and safety of B-cell depletion as a therapeutic avenue.

TRIAL REGISTRATION

NCT04540497.

Utilization of FDA approved treatments for neuromyelitis optica spectrum disorder in clinical practice: A survey study of academic neuroimmunologists

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune condition for which three treatments have been approved since 2019: eculizumab, inebilizumab, and satralizumab. We conducted a survey of U.S. academic neuroimmunologists to assess adoption of these therapies and barriers to use. Thirty-three neuroimmunologists from 18 states completed the survey. Nearly all (88 %) reported using the novel NMOSD treatments (NNTs). They uncommonly switched clinically stable patients to NNTs (69 % switched none, 22 % switched 1-25 % of their patients). For newly diagnosed patients, NNT initiation rates varied. Following relapse, respondents were dichotomized, either switching 75-100 % of patients (60 %) or 0-25 % (40 %). Insurance and cost-related barriers were common.

Monoclonal Antibody Therapies Beyond Complement for NMOSD and MOGAD

Aquaporin-4 (AQP4)-IgG seropositive neuromyelitis optica spectrum disorders (AQP4-IgG seropositive NMOSD) and myelin oligodendrocyte glycoprotein (MOG)-IgG-associated disease (MOGAD) are inflammatory demyelinating disorders distinct from each other and from multiple sclerosis (MS).While anti-CD20 treatments can be used to treat MS and AQP4-IgG seropositive NMOSD, some MS medications are ineffective or could exacerbate AQP4-IgG seropositive NMOSD including beta-interferons, natalizumab, and fingolimod. AQP4-IgG seropositive NMOSD has a relapsing course in most cases, and preventative maintenance treatments should be started after the initial attack. Rituximab, eculizumab, inebilizumab, and satralizumab all have class 1 evidence for use in AQP4-IgG seropositive NMOSD, and the latter three have been approved by the US Food and Drug Administration (FDA). MOGAD is much more likely to be monophasic than AQP4-IgG seropositive NMOSD, and preventative therapy is usually reserved for those who have had a disease relapse. There is a lack of any class 1 evidence for MOGAD preventative treatment. Observational benefit has been suggested from oral immunosuppressants, intravenous immunoglobulin (IVIg), rituximab, and tocilizumab. Randomized placebo-controlled trials are urgently needed in this area.

Pharmacodynamic modeling and exposure-response assessment of inebilizumab in subjects with neuromyelitis optica spectrum disorders

Aims

Neuromyelitis optica spectrum disorders (NMOSD) is an autoantibody‐mediated, B cell‐driven disease. Inebilizumab is a humanized, affinity‐optimized, afucosylated IgG1 κ monoclonal antibody that binds to the B‐cell specific surface antigen CD19, resulting in rapid, profound and sustained depletion of circulating peripheral B cells in NMOSD subjects (pivotal study). The objective of this study was to conduct population modelling of B‐cell response following inebilizumab treatment in adult subjects with NMOSD, and to assess the impact of drug exposure to outcome.

Methods

A haematopoietic transit model was developed to describe the joint effects of reducing influx from pro‐B cells and accelerating CD20⁺ B‐cell depletion in the blood by inebilizumab. Furthermore, the relationships between inebilizumab pharmacokinetic (PK) exposure and the primary efficacy endpoint and key secondary efficacy endpoints were evaluated.

Results

At the 300‐mg dose, there was no apparent relationship between efficacy (reduction in disease attack risk, risk of worsening from baseline in Expanded Disability Status Scale, cumulative total active MRI lesions, and the number of NMOSD‐related in‐patient hospitalizations) and PK exposure. Subjects with low, medium and high PK exposure had a similar hazard ratio of NMOSD attack vs. placebo group.

Conclusion

The pharmacodynamic modelling confirmed effective depletion of B cells is achieved with a 300 mg intravenous dose of inebilizumab administered on Day 1 and Day 15 and every 6 months thereafter. The PK variability between patients had no apparent effect on clinical efficacy.

Inebilizumab for treatment of neuromyelitis optica spectrum disorder in patients with prior rituximab use from the N-MOmentum Study

BACKGROUND

The B-cell-depleting agent rituximab (anti-CD20) was historically used to prevent attacks in neuromyelitis optica spectrum disorder (NMOSD). Inebilizumab, which targets and depletes CD19-expressing B cells, plasmablasts, and some plasma cells, received approval from the US Food and Drug Administration for treatment of NMOSD based on results from the randomized, placebo-controlled, phase 2/3 N-MOmentum trial. Because of their closely related mechanisms of action, consideration as to whether inebilizumab may be a suitable treatment option for patients with prior rituximab experience is important. This post hoc analysis of data from N-MOmentum assessed inebilizumab efficacy and tolerability in participants previously treated with rituximab.

METHODS

Adjudicated attacks, secondary efficacy outcomes, and treatment-emergent adverse events were assessed by prior rituximab use during a 6-month randomized control period and open-label period.

RESULTS

Seventeen participants in N-MOmentum had prior rituximab use, of whom 13 were randomly assigned to the inebilizumab treatment group. Seven of these participants had breakthrough attacks prior to enrollment (annualized attack rate, 0.78 attacks/person-year) despite rituximab use. While they were receiving inebilizumab in the randomized control period, 1 of 13 participants with prior rituximab use had an attack (hazard ratio vs all placebo, 0.16; 95% confidence interval: 0.02 1.20; p = 0.07). Two additional participants with prior rituximab use experienced attacks on inebilizumab during the open-label period, with an overall annualized attack rate of 0.08 (95% confidence interval: 0.02 0.34) attacks/person-year. This annualized attack rate was similar to that of participants without prior rituximab use (0.10 [95% confidence interval: 0.07 0.15]). None of the 7 participants who experienced attacks while taking rituximab experienced an attack while receiving inebilizumab. Two (12%) participants with prior rituximab use experienced serious treatment-emergent adverse events related to inebilizumab, with serious or grade ≥3 infections occurring in 3 (18%) participants each. No deaths or opportunistic infections were reported in this cohort.

CONCLUSIONS

These findings support the efficacy of inebilizumab in participants with NMOSD who had previously been treated with rituximab. Infections occurred in nearly all study participants with prior rituximab exposure, highlighting a need for clinical vigilance in such individuals. Further studies are necessary to determine potential safety concerns of inebilizumab, including risk of infection, in rituximab-experienced patients. ClinicalTrials.gov identifier: NCT02200770.

Network Meta-analysis of Food and Drug Administration-approved Treatment Options for Adults with Aquaporin-4 Immunoglobulin G-positive Neuromyelitis Optica Spectrum Disorder

INTRODUCTION

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease defined by attacks on the central nervous system that cause irreversible damage. Recent approval of NMOSD therapies warrants investigations of comparative efficacy to inform treatment decisions.

METHODS

A network meta-analysis (NMA) of all U.S. Food and Drug Administration-approved therapies (eculizumab, inebilizumab, and satralizumab) for adults with aquaporin-4 immunoglobulin G-positive (AQP4+) NMOSD was conducted via a systematic literature review (SLR) using data from randomized controlled trials (RCTs). Database searches of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were executed for the SLR. A fixed-effects proportional hazards Bayesian NMA was used to estimate relative treatment effects based on data extracted from RCTs identified during the SLR (search end date: 11 September 2020). Four unique RCTs (N-MOmentum, PREVENT, SAkuraSky, and SAkuraStar) were identified, and data from 29 publications were extracted for analysis. Network scenarios describing the most comparable patient population groups (such as by treatment settings) were evaluated in our analyses. Relative treatment effects were evaluated based on time-to-first relapse and were expressed as hazard ratios (HRs) with 95% credible intervals (CrIs).

RESULTS

In patients treated with a monoclonal antibody only, eculizumab was associated with a lower risk of relapse compared with satralizumab (HR 0.10, 95% CrI 0.01, 0.65) and inebilizumab (HR 0.11, 95% CrI 0.02, 0.68). In patients treated with monoclonal antibody with or without background immunosuppressive therapy (IST), patients treated with eculizumab ± IST were also less likely to relapse than patients treated with satralizumab ± IST (HR 0.24, 95% CrI 0.06, 0.98).

CONCLUSION

The NMA results suggest that complement component 5 (C5) inhibition prevents NMOSD relapses more effectively than broader mechanisms of action.

Inebilizumab in AQP4-Ab-positive neuromyelitis optica spectrum disorder

Until recently, the use of preventative immunotherapy in neuromyelitis optica spectrum disorders (NMOSD) was based on observational studies and clinical experiences. Meanwhile, the first drugs, among others the monoclonal antibody inebilizumab, were approved for the treatment of aquaporin-4 (AQP4) antibody-positive NMOSD. Inebilizumab binds to the CD19 antigen on B cells and leads to B-cell depletion. The first two dosages of 300 mg inebilizumab are administered intravenously at an interval of 2 weeks followed by further infusions every 6 months. In the placebo-controlled pivotal phase II/III study N-MOmentum, inebilizumab significantly prolonged the time to a first adjudicated relapse in AQP4 antibody-positive patients compared with placebo. The most frequent side effects were infusion reactions, urinary and respiratory tract infections, and arthralgia. This review presents data on clinical and preclinical pharmacology, administration, safety aspects and clinical trials of inebilizumab.

Effectiveness of treatments in Neuromyelitis optica to modify the course of disease in adult patients. Systematic review of literature

BACKGROUND

Neuromyelitis Optica spectrum disorder (NMOSD) is an inflammatory disease, which manifests mostly as recurrent episodes of optic neuritis or myelitis that cause important disability. Early diagnosis and prompt initiation of immunosuppressive therapy are crucial in reducing relapses, disability, and mortality. Even though, there are few prospective randomized controlled trials, several drugs have proved to be both effective and safe. Azathioprine and Rituximab represent the standard of care and are used as first-line treatment agents worldwide. However, recent studies have unveiled new therapies, such as monoclonal antibodies. To make treatment recommendations and management guidelines, it is imperative to define an appropriate standard of care.

METHODS

A systematic literature review was performed in MEDLINE, EMBASE, and LILACS databases using the following terms: "(NMO OR Devic OR Neuromyelitis Optica) AND (Azathioprine OR Prednisone OR Rituximab OR Tocilizumab OR Bortezomib OR Inebilizumab OR Eculizumab OR Satralizumab)" including both, randomized clinical trials and observational studies published between January 2006 and January 2021. The inclusion criteria comprised patients aged 18 or older, NMOSD diagnosis following the Wingerchuck criteria, two or more therapies been compared, and the evaluation of both efficacy and safety outcomes. All studies comparing treatment only with placebo were excluded. Quality was assessed according with the design of the study, and results were synthesized through comparative tables for each outcome evaluated, differentiating the results of randomized and non-randomized studies.

RESULTS

Thirteen studies with 1447 patients were included. Twelve studies evaluated the expanded disability status scale (EDSS) before and after treatment; in five of seven evaluating rituximab, it outperformed its comparators in improving the disability degree. Eleven studies assessed the annual relapse rate (ARR). Again, in six of seven evaluating rituximab, it was superior to other therapies. Time to relapse (TTR) was reported in five studies. The three studies that included Rituximab revealed a longer time to relapse in this arm of treatment. Finding were consistent in randomized and non-randomized studies. The new molecules Satralizumab, Eculizumab and Tocilizumab were evaluated in one study each, proving to be highly effective and safe. The safety profile analysis showed a higher number of adverse events for Azathioprine.

DISCUSSION

This systematic review demonstrates a superiority tendency of Rituximab upon the other treatments strengthening the available evidence about NMOSD management. Superiority in EDSS outcomes, annual relapse rate, time to first relapse and relapses during treatment time was evidenced in the Rituximab group compared to other medications, with lower rates of adverse events. New molecules Tocilizumab, Eculizumab and Satralizumab also showed superiority in the evaluated results, especially in the relapses during treatment time outcome, although with subtle differences in EDSS and ARR outcomes.

CONCLUSION

Our results suggest that monoclonal antibodies are highly effective and safe for the treatment of NMOSD; Rituximab showed better performance on multiple outcomes and has more evidence available. New molecules: Eculizumab, Tocilizumab, Satralizumab are good options for treatment. Drugs like Azathioprine and Mycophenolate are effective, but with a worse risk-benefit ratio, therefore, they are useful alternatives in places that do not have access to monoclonal antibodies.

ESCMID Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biological therapies: an infectious diseases perspective (Agents targeting lymphoid cells surface antigens [I]: CD19, CD20 and CD52)

BACKGROUND

The present review is part of the ESCMID Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biological therapies.

AIMS

To review, from an Infectious Diseases perspective, the safety profile of agents targeting CD19, CD20 and CD52 and to suggest preventive recommendations.

SOURCES

Computer-based MEDLINE searches with MeSH terms pertaining to each agent or therapeutic family.

CONTENT

Although CD19-targeted agents (blinatumomab or inebilizumab) are not associated with an increased risk of infection, they may cause IgG hypogammaglobulinaemia and neutropenia. The requirement for prolonged intravenous infusion of blinatumomab may increase the risk of catheter-associated bloodstream infections. Infection remains the most common non-haematological adverse effect of anti-CD20 monoclonal antibodies, including severe respiratory tract infection, hepatitis B virus (HBV) reactivation and varicella-zoster virus infection. Screening for chronic or resolved HBV infection is recommended for patients receiving anti-CD20 monoclonal antibodies. Antiviral prophylaxis should be offered for 12-18 months to hepatitis B surface antigen (HBsAg)-positive and HBsAg-negative/anti-hepatitis B core antibody (HBc)-positive patients. Anti-Pneumocystis prophylaxis should be considered in patients receiving concomitant chemotherapy, particularly steroids. Alemtuzumab (anti-CD52) increases the risk of infections, in particular among leukaemia and solid organ transplant patients. These populations benefit from anti-Pneumocystis prophylaxis, prevention strategies for cytomegalovirus infection, and screening for HBV, hepatitis C virus and tuberculosis. Antiviral prophylaxis for at least 6-12 months should be provided for HBsAg-positive patients.

IMPLICATIONS

As there are limited clinical data for many of the reviewed agents, special attention must be given to promptly detect and report emerging infectious complications.

A lifetime aging study of human CD19 transgenic mice

Mice transgenic for human CD19 have been an important animal model to help understand the role of this molecule in B lymphocyte function. Previously, no lifetime studies had been performed to understand the effects of this CD19 over expression on the survival or spontaneous pathology within the C57BL/6J background strain. We conducted a lifetime study with interim sacrifices to understand the transgenic effects on clinical signs, body weight, survival, and spontaneous pathology. Blood and urine samples were collected from select animals at various time points during the study for measurement of clinical pathology parameters and groups of animals were euthanized and examined at predetermined intervals. There was fair survival with some animals living to 108 weeks of age. Clinical pathology evaluations revealed a declining red cell mass with a regenerative anemia, increasing total white blood cell counts and decreasing glucose level. Total protein, albumin, and globulin levels increased to 52 weeks of age and then declined to or below baseline with advancing age. Increased urinary microalbumin levels correlated with the severity of a glomerulopathy at 76 and 84 weeks of age. Mean body weight increased through 70 weeks and then declined to weights similar to week 28 at 108 weeks. Macroscopic observations included pale kidneys, enlarged seminal vesicles, and enlarged spleens (at 108 weeks of age). The most common neoplasms in this study were bronchiolar alveolar adenomas in the lung, histiocytic sarcoma in several different tissues, and hepatocellular adenomas. The most common non-neoplastic lesions were renal glomerulopathy, and pulmonary lymphocytic infiltrates with increased numbers of alveolar macrophages.