Subcutaneous IgG in neurologic diseases

Contribution of Flexig mobile application to assess adherence of patients treated with immunoglobulins in chronic diseases

Background

Long-term therapeutic adherence remains an essential challenge for better management of chronic diseases. It is estimated at 50% in developed countries.

Objective

The study aimed to evaluate, under real conditions, the influence of satisfaction with Flexig use on adherence to subcutaneous immunoglobulin home-treatment therapy in a sample of French patients with chronic dysimmune diseases.

Methods

This is a 2-year prospective cohort involving 241 patients from several hospitals in France whose data were extracted from the Flexig 2.0 mHealth application. Satisfaction was assessed by System Usability Scale (SUS) and user experience by User Experience Questionnaire (UEQ). Adherence to Ig therapy was assessed by medication possession rate. We analyzed the relationship between Flexig user satisfaction and adherence to treatment, as well as determinants of adherence.

Results

Most patients (82.7%) were being treated for an immunodeficiency, versus 17.3% for a chronic autoimmune and inflammatory disease. Almost all patients (97.9%) received subcutaneous immunoglobulin therapy. The patients' ages (means ± SDs) were 36.5 ± 18.3 years, disease duration was about 6 years, and 58.5% were men. Flexig user satisfaction was 76.2 ± 8 (System Usability Scale), associated with good user experience reported on UEQ. Adherence rate was 99.7%. Time on app, disease duration, and Flexig user satisfaction were statistically predictive of adherence to IgG therapy. High adherence to Ig therapy was associated with good satisfaction with using Flexig (P < .0001).

Conclusion

Adherence to Ig therapy in chronic dysimmune disease was strong and was associated with good satisfaction among Flexig users, suggesting that electronic support may be a valuable compliance aid.

Titanium-based metal-organic framework MIL-125(Ti) for the highly selective isolation and purification of immunoglobulin G from human serum

Titanium-based metal-organic framework MIL-125(Ti) was synthesized by the hydrothermal method of terephthalic acid and tetra butyl titanate in N-N dimethylformamide and methanol. MIL-125(Ti) was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, nitrogen adsorption-desorption, energy-dispersive X-ray spectroscopy, zeta potential, scanning electron microscope and transmission electron microscopy. The results showed MIL-125(Ti) could be used as a potential adsorbent for protein separation and purification due to the high specific surface area, high stability and strong hydrophobicity. As a result, MIL-125(Ti) had adsorption selectivity for immunoglobulin G, which was due to hydrogen bond between MIL-125(Ti) and protein. At pH 8.0, the maximum adsorption efficiency of 0.25 mg MIL-125(Ti) for 300 μL 100 μg mL^-1 immunoglobulin G was 98.3%, and its maximum adsorption capacity was 232.56 mg g^-1 . The elution efficiency of immunoglobulin G was 92.4% by 0.1% SDS. SDS-PAGE result demonstrated the successful isolation of highly purified immunoglobulin G from the human serum. Therefore, a new method of separation and purification of immunoglobulin G in human serum using titanium-based metal-organic framework MIL-125(Ti) as a solid-phase adsorbent was established, which broadened the application scope of metal-organic frameworks. This article is protected by copyright. All rights reserved.

Update on Intravenous Immunoglobulin in Neurology: Modulating Neuro-autoimmunity, Evolving Factors on Efficacy and Dosing and Challenges on Stopping Chronic IVIg Therapy

In the last 25 years, intravenous immunoglobulin (IVIg) has had a major impact in the successful treatment of previously untreatable or poorly controlled autoimmune neurological disorders. Derived from thousands of healthy donors, IVIg contains IgG1 isotypes of idiotypic antibodies that have the potential to bind pathogenic autoantibodies or cross-react with various antigenic peptides, including proteins conserved among the "common cold"-pre-pandemic coronaviruses; as a result, after IVIg infusions, some of the patients' sera may transiently become positive for various neuronal antibodies, even for anti-SARS-CoV-2, necessitating caution in separating antibodies derived from the infused IVIg or acquired humoral immunity. IVIg exerts multiple effects on the immunoregulatory network by variably affecting autoantibodies, complement activation, FcRn saturation, FcγRIIb receptors, cytokines, and inflammatory mediators. Based on randomized controlled trials, IVIg is approved for the treatment of GBS, CIDP, MMN and dermatomyositis; has been effective in, myasthenia gravis exacerbations, and stiff-person syndrome; and exhibits convincing efficacy in autoimmune epilepsy, neuromyelitis, and autoimmune encephalitis. Recent evidence suggests that polymorphisms in the genes encoding FcRn and FcγRIIB may influence the catabolism of infused IgG or its anti-inflammatory effects, impacting on individualized dosing or efficacy. For chronic maintenance therapy, IVIg and subcutaneous IgG are effective in controlled studies only in CIDP and MMN preventing relapses and axonal loss up to 48 weeks; in practice, however, IVIg is continuously used for years in all the aforementioned neurological conditions, like is a "forever necessary therapy" for maintaining stability, generating challenges on when and how to stop it. Because about 35-40% of patients on chronic therapy do not exhibit objective neurological signs of worsening after stopping IVIg but express subjective symptoms of fatigue, pains, spasms, or a feeling of generalized weakness, a conditioning effect combined with fear that discontinuing chronic therapy may destabilize a multi-year stability status is likely. The dilemmas of continuing chronic therapy, the importance of adjusting dosing and scheduling or periodically stopping IVIg to objectively assess necessity, and concerns in accurately interpreting IVIg-dependency are discussed. Finally, the merit of subcutaneous IgG, the ineffectiveness of IVIg in IgG4-neurological autoimmunities, and genetic factors affecting IVIg dosing and efficacy are addressed.

Practical Aspects of Transitioning from Intravenous to Subcutaneous Immunoglobulin Therapy in Neuromuscular Disorders

Recent evidence shows that subcutaneous immunoglobulin (SCIG) is as efficacious as intravenous immunoglobulin (IVIG) and has a better safety profile and acceptance rate among patients with neuromuscular disorders who require maintenance IVIG treatment. Awareness of the practical aspects of patient selection, enrollment, dose calculation, administration, and follow-up would help physicians coordinate a smooth and seamless transition from IVIG to SCIG. SCIG is ideally offered to patients having intolerable side effects during IVIG or wearing-off effect and in those keen for treatment autonomy. The weekly dose of SCIG is calculated by multiplying the maintenance dose of IVIG by the dose adjustment factor and dividing by the interval between IVIG in weeks and is initiated 1 week after the last dose of IVIG. The physician places the order for the SCIG and the clinic nurse or the physician refers the patient to the home care nursing program for further education and training. The necessary supplies are dispatched to the patient who would also collect the SCIG from the transfusion center of the nearest hospital. The patient is educated on assembling and administering the infusion, and home visits are continued until the patient or caregiver is confident. Regular follow-up with the patient is maintained to assess treatment response and side effects if any. With a smooth transition, most patients have excellent tolerance to SCIG and in our experience seldom request switching back to IVIG. Transitioning patients from IVIG to SCIG offers several advantages and thus, in general, is preferable for multiple stakeholders.

Expanding the Role of the Pharmacist: Immunoglobulin Therapy and Disease Management in Neuromuscular Disorders

Immunoglobulin G (IgG) is a commonly used treatment for chronic neuromuscular disorders (NMDs), such as chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy. IgG therapy has also shown promise in treating other NMDs including myasthenia gravis, polymyositis, and dermatomyositis. IgG is administered as either intravenous immunoglobulin (IVIg) or subcutaneous immunoglobulin (SCIg), with SCIg use becoming more popular due to the treatment burden associated with IVIg. IVIg requires regular venous access; long infusions (typically 4-6 hours); and can result in systemic adverse events (AEs) for some patients. In contrast, SCIg can be self-administered at home with shorter infusions (approximately 1 hour) and fewer systemic AEs. As patient care shifts toward home-based settings, the role of the pharmacist is paramount in providing a continuation of care and acting as the bridge between patient and clinic. Pharmacists with a good understanding of current recommendations, dosing strategies, and administration routes for IgG therapy are best placed to support patients. The aims of this review are to highlight the evidence supporting IgG therapy in the treatment of NMDs and provide practical information on patient management and IVIg/SCIg dosing in order to guide pharmacists on optimizing clinical outcomes and patient care.

Novel Treatments in Myasthenia Gravis

Myasthenia gravis (MG) is the prototypical autoimmune disorder caused by specific autoantibodies at the neuromuscular junction. Broad-based immunotherapies, such as corticosteroids, azathioprine, mycophenolate, tacrolimus, and cyclosporine, have been effective in controlling symptoms of myasthenia. While being effective in a majority of MG patients many of these immunosuppressive agents are associated with long-term side effects, often intolerable for patients, and take several months to be effective. With advances in translational research and drug development capabilities, more directed therapeutic agents that can alter the future of MG treatment have been developed. This review focuses on the aberrant immunological processes in MG, the novel agents that target them along with the clinical evidence for efficacy and safety. These agents include terminal complement C5 inhibitors, Fc receptor inhibitors, B cell depleting agents (anti CD 19 and 20 and B cell activating factor [BAFF)]inhibitors), proteosome inhibitors, T cells and cytokine based therapies (chimeric antigen receptor T [CART-T] cell therapy), autologous stem cell transplantation, and subcutaneous immunoglobulin (SCIG). Most of these new agents have advantages over conventional immunosuppressive treatment (IST) for MG therapy in terms of faster onset of action, favourable side effect profile and the potential for a sustained and long-term remission.

Challenges and innovations of drug delivery in older age

Both drug delivery performance and various age-related physical, mental and physiological changes can affect drug effectiveness and safety in elderly patients. The many drug delivery systems developed over the years include recent novel transdermal, nasal, pulmonary and orally disintegrating tablets that provide consistent, precise, timely and more targeted drug delivery. Certain drug delivery systems may be associated with suboptimal outcomes in the elderly because of the nature of drug present, a lack of appreciation of the impact of age-related changes in drug absorption, distribution and clearance, the limited availability of pharmacokinetic, safety and clinical data. Polypharmacy, patient morbidity and poor adherence can also contribute to sub-optimal drug delivery systems outcomes in the elderly. The development of drug delivery systems for the elderly is a poorly realised opportunity, with each system having specific advantages and limitations. A key challenge is to provide the innovation that best meets the specific physiological, psychological and multiple drug requirements of individual elderly patients.

The FcRn inhibitor rozanolixizumab reduces human serum IgG concentration: A randomized phase 1 study

Pathogenic immunoglobulin G (IgG) autoantibodies characterize some human autoimmune diseases; their high concentration and long half-life are dependent on recycling by the neonatal Fc receptor (FcRn). Inhibition of FcRn is an attractive new treatment concept for IgG-mediated autoimmune diseases. Rozanolixizumab (UCB7665; CA170_01519.g57 IgG4P) is an anti-human FcRn monoclonal antibody. In cynomolgus monkeys, rozanolixizumab reduced IgG (maximum 75 to 90% by about day 10), was well tolerated, and did not increase risk of infection. We also report a first-in-human, randomized, double-blind, placebo-controlled, dose-escalating study of intravenous (IV) or subcutaneous (SC) rozanolixizumab in healthy subjects (NCT02220153). The primary objective was to evaluate safety and tolerability. Secondary objectives were assessment of rozanolixizumab pharmacokinetics and pharmacodynamics, including effects on circulating IgG concentrations. Forty-nine subjects were randomized to receive rozanolixizumab (n = 36) or placebo (n = 13) across six cohorts. The first three cohorts received IV doses, and the subsequent three cohorts received SC doses, of rozanolixizumab 1, 4, or 7 mg/kg (n = 6 for each cohort; plus n = 7 or 6 for placebo, respectively). The most frequent treatment-emergent adverse event [TEAE; headache, 14 of 36 (38.9%) subjects] was dose-dependent and more prominent after IV administration. Severe TEAEs occurred in four subjects, all in the highest-dose IV group [headache (n = 3) and back pain (n = 1)]. Rozanolixizumab pharmacokinetics demonstrated nonlinear increases with dose. There were sustained dose-dependent reductions in serum IgG concentrations (IV and SC rozanolixizumab). These data provide clinical evidence for the therapeutic potential of rozanolixizumab.

Efficacy and patient satisfaction in the use of subcutaneous immunoglobulin immunotherapy for the treatment of auto-immune neuromuscular diseases

We reviewed the efficacy of SCIg administration in terms of muscle strength maintenance and patient satisfaction comparing with IVIg in the treatment of auto-immune neuromuscular diseases. A systematic review was conducted, and identified studies from databases (PUBMED, EMBASE, EBSCO, Web of Science and Google Scholar) which were analyzed. The methodological quality of the selected publications was evaluated using the Newcastle-Ottawa Scale. Data were extracted from a total of 11 studies Fixed and random-effect model meta-analyses were performed. For the maintenance of muscle strength, Overall Neuropathy Limitations Scale (ONLS) data from 100 patients diagnosed with multifocal mononeuropathy (MMN) or chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) were pooled together. Switching to subcutaneous immunoglobulin administration led to a significant improvement (fixed effects model, p = 0.002). In data collected using the Medical Research Council Scale for Muscle Strength data from 140 patients with a wider range of disorders, a small but significant improvement in overall strength was observed in the SCIg group (p < 0.0001). In addition, the results of two studies measuring health-related quality of life and patient satisfaction were pooled. Data from 49 patients suffering from MMN, CIDP, and a variety of different myopathies demonstrated a small but significant increase in the mean 36-Item Short Form Survey (SF-36) scores (p < 0.0001). A highly significant difference was revealed when comparing data from 119 patients' responses to the Life Quality Index questionnaire (LQI) assessing patient satisfaction (p < 0.0001). This is the first analysis showing that SCIg is more effective than IVIg in improving Patient Reported Outcomes in auto-immune neuromuscular disease. These results should permit a broad range of patients to self-administer immunoglobulin treatments at home, potentially improving patient acceptability while reducing hospital visits and healthcare costs for the treatment of chronic auto-immune neuropathies.

Subcutaneous immunoglobulin for the treatment of deep morphoea in a child

Morphoea, also known as localized scleroderma, is a disorder characterized by excessive collagen deposition leading to thickening of the dermis and/or subcutaneous tissues. Intravenous IgG therapy has induced improvement in some fibrotic conditions. The primary indication for subcutaneous IgG (SCIG) is in primary immunodeficiency disorders as replacement therapy; however, recently there has been considerable interest in SCIG as an immunomodulatory agent. We report an 11-year-old girl with deep morphoea who was successfully treated with SCIG.

Maintenance IV immunoglobulin treatment in chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients treated with intravenous immunoglobulin (IVIg) usually start with a standard dosage of 2 g/kg bodyweight. Only a minority of patients has a sustained improvement, and most require ongoing maintenance treatment. Preferred IVIg regimens, however, vary considerably between doctors and at present it is unknown which is optimal. As there are also large differences in IVIg dosage and interval requirements between patients, optimal IVIg maintenance treatment of CIDP is even more complex. The lack of evidence-based guidelines on how IVIg maintenance treatment should be administered may potentially lead to under- or overtreatment of this expensive therapy. We provide an overview of published practical IVIg maintenance treatment regimens, IVIg maintenance schedules used in randomized controlled trials and one based upon our own long-term experience on how this treatment could be given in CIDP.

Subcutaneous immunoglobulin in myasthenia gravis exacerbation: A prospective, open-label trial

OBJECTIVE

To investigate the efficacy, tolerability, and safety of subcutaneous immunoglobulin (SCIg) in patients with mild to moderate myasthenia gravis (MG) exacerbation.

METHODS

We performed a prospective, open-label, phase 3 trial in patients with MG aged 18 years or older and mild to moderate worsening (transition from Myasthenia Gravis Foundation of America class I to II/III or class II to III), treated with SCIg (2 g/kg), self-administered over 4 weeks. The primary endpoint was change in quantitative MG (QMG) score from baseline to study end at 6 weeks. Secondary endpoints included change in manual muscle testing (MMT), MG activities of daily living (MG-ADL), and MG composite (MGC) scores, as well as occurrence of adverse events, and tolerability as assessed via Treatment Satisfaction Questionnaire for Medication (TSQM).

RESULTS

Twenty-two of 23 patients completed the study. QMG score decreased from 14.9 ± 4.1 to 9.8 ± 5.6 (p < 0.0001), MMT score decreased from 16.8 ± 9.5 to 5.2 ± 4.5 (p < 0.0001), MG-ADL score decreased from 9.5 ± 3.0 to 4.6 ± 3.0 (p < 0.0001), and MGC score decreased from 17.4 ± 5.0 to 5.6 ± 4.5 (p < 0.0001). Satisfaction by TSQM was high (79.6 ± 15.6%). Common adverse events included headache and injection site reactions. No serious adverse events occurred.

CONCLUSIONS

SCIg is well-tolerated, safe, and effective in mild to moderate MG exacerbation. Comparative safety and efficacy must be established with randomized controlled trials.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that in patients with mild to moderate MG exacerbation, SCIg is safe and effective in reducing MG disability measures.

Impact of Immunoglobulin Therapy in Pediatric Disease: a Review of Immune Mechanisms

Intravenous immunoglobulin (IVIG) provides replacement therapy in immunodeficiency and immunomodulatory therapy in inflammatory and autoimmune diseases. This paper describes the immune mechanisms underlying six major non-primary immunodeficiency pediatric diseases and the diverse immunomodulatory functions of IVIG therapy. In Kawasaki disease, IVIG plays a major, proven, and effective role in decreasing aneurysm formation, which represents an aberrant inflammatory response to an infectious trigger in a genetically predisposed individual. In immune thrombocytopenia, IVIG targets the underlying increased platelet destruction and decreased platelet production. Although theoretically promising, IVIG shows no clear clinical benefit in the prophylaxis and treatment of neonatal sepsis. Limitations in research design combined with the unique neonatal immunologic environment offer explanations for this finding. Inflammation from aberrant immune activation underlies the myelinotoxic effects of Guillain-Barré syndrome. HIV-1 exerts a broad range of immunologic effects and was found to decrease serious bacterial infections in the pre-highly active anti-retroviral therapy (HAART) era, although its practical relevance in the post-HAART era has waned. Clinical and experimental data support the role of immune mechanisms in the pathogenesis of childhood epilepsy. IVIG exerts anti-epileptic effects through targeting upregulated cytokine pathways and antibodies thought to contribute to epilepsy. Applications in six additional pediatric diseases including pediatric asthma, atopic dermatitis, cystic fibrosis, pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS), autism, and transplantation will also be briefly reviewed. From autoimmunity to immunodeficiency, a dynamic immunologic basis underlies major pediatric diseases and highlights the broad potential of IVIG therapy.

Subcutaneous Immunoglobulin Therapy in the Chronic Management of Myasthenia Gravis: A Retrospective Cohort Study

BACKGROUND

Immunoglobulin therapy has become a major treatment option in several autoimmune neuromuscular disorders. For patients with Myasthenia Gravis (MG), intravenous immunoglobulin (IVIg) has been used for both crisis and chronic management. Subcutaneous Immunoglobulins (SCIg), which offer the advantage of home administration, may be a practical and effective option in chronic management of MG. We analyzed clinical outcomes and patient satisfaction in nine cases of chronic disabling MG who were either transitioned to, or started de novo on SCIg.

METHODS AND FINDINGS

This was a retrospective cohort study for the period of 2015-2016, with a mean follow-up period of 6.8 months after initiation of SCIg. All patients with MG treated with SCIg at the Ottawa Hospital, a large Canadian tertiary hospital with subspecialty expertise in neuromuscular disorders were included, regardless of MG severity, clinical subtype and antibody status. The primary outcome was MG disease activity after SCIg initiation. This outcome was measured by 1) the Myasthenia Gravis Foundation of America (MGFA) clinical classification, and 2) subjective scales of disease activity including the Myasthenia Gravis activities of daily living profile (MG-ADL), Myasthenia Gravis Quality-of-life (MG-QOL 15), Visual Analog (VA) satisfaction scale. We also assessed any requirement for emergency department visits or hospitalizations. Safety outcomes included any SCIg related complication. All patients were stable or improved for MGFA class after SCIg initiation. Statistically significant improvements were documented in the MG-ADL, MG-QOL and VAS scales. There were no exacerbations after switching therapy and no severe SCIg related complications.

CONCLUSIONS

SCIg may be a beneficial therapy in the chronic management of MG, with favorable clinical outcome and patient satisfaction results.

Quantitative Evidence of Wear-Off Effect at the End of the Intravenous IgG (IVIG) Dosing Cycle in Primary Immunodeficiency

PURPOSE

Intravenous IgG (IVIG) treatment wear-off is commonly experienced by patients, who report increased susceptibility to infection, and decreased quality of life towards the end of their 3- or 4-week dosing cycle, when serum IgG levels approach their trough. We quantified IVIG wear-off in terms of treatment efficacy and patient well-being.

METHODS

Data were collected from patients enrolled in three Phase III trials of Sandoglobulin NF Liquid or Privigen, treated every 3- or 4- weeks. Pooled analyses of raw patient data compared the rate of infection and other clinical outcomes during the course of the dosing cycle. Subjective symptoms of wear-off were quantified by comparing patient-reported overall well-being scores.

RESULTS

The probability of a first infection in the final week of the IVIG cycle was 1.26 (95% confidence intervals [CI]: 0.76-2.11; p = 0.3621) and 1.55 (95% CI: 1.04-2.32; p = 0.0314) times higher than in the first week, for patients on a 3-week cycle and 4-week dosing cycles, respectively. Wear-off, as manifested by a decrease in overall well-being, was experienced in 10% of all cycles and reported at least once by 61% of the patients on a 3-week cycle, and 43% of those on a 4-week cycle.

CONCLUSIONS

These findings confirm the existence of decreased efficacy (treatment wear-off) towards the end of a 3-4 week IVIG dosing cycle, and provide a quantifiable evaluation to a phenomenon typically reported anecdotally. For patients experiencing wear-off, increasing the IgG dose or shortening the dosing interval and/or a switch to SCIG may be beneficial.

Overcoming challenges in the diagnosis and treatment of myasthenia gravis

In recent years, the discovery of new autoantigens and the use of sensitive assays have expanded the clinical spectrum of myasthenia gravis (MG). In particular, antibodies binding to clustered acetylcholine receptors and to the low-density lipoprotein receptor-related protein 4 have not only bridged a significant gap in diagnosis but also have relevant clinical implications. MG management includes different therapeutic options, from symptomatic agents as the only therapy in mildly affected cases to combined long-term immunosuppression and thymectomy in patients with severe disabling disease. MG biological diversity can influence the response to therapies and should be taken into account when planning treatment. Biologic agents are promising, though their use is currently limited to patients with refractory disease.