Intravenous immunoglobulin treatment in chronic inflammatory demyelinating polyradiculoneuropathy, a time to start and a time to stop

Safety and Cost Analysis of Immunoglobulin Cessation Trials in Chronic Inflammatory Demyelinating Polyradiculoneuropathy

BACKGROUND AND AIMS

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is the most common chronic autoimmune neuropathy worldwide. A significant proportion of CIDP patients enter spontaneous or medication-related remission, remaining stable without immunotherapy. Overtreatment of CIDP has clinical and financial implications. We examined performance of IVIg cessation trials in our CIDP cohort and report safety and cost analysis outcomes.

METHODS

In individuals with CIDP on maintenance IVIg treatment, a cessation trial was proposed in clinically stable patients with a static IVIg regimen over a 12-month period. We explored the proportion who were stable off treatment for 12 or more months and the time to recovery in those who declined and were re-treated. We examined cost implications of this approach.

RESULTS

45/125 individuals met criteria for clinical stability, with median age 58 years, I-RODS 37/48, MRC-SS 69/70 and annual treatment costs £107 000/person. Nine individuals had cessation trials resulting in decline within 2 years prior and were not re-challenged, leaving 36 eligible individuals. 12 of 36 (33.3%) consented to cessation trial and eight of those (66.7%) remained stable off treatment for ≥ 12 months. The successful cessation trials resulted in a cost saving of £855 000/year, with a potential further saving of £1.7 million/year if all the eligible individuals had consented. All patients who deteriorated were rescued to previous baseline on retreatment.

INTERPRETATION

Individuals with CIDP should be counselled about the natural history of the disease and future scheduled, targeted cessation trials. A dedicated clinical infrastructure is vital to safely perform cessation trials.

B-cell and T-cell receptor repertoire in chronic inflammatory demyelinating polyneuropathy, a prospective cohort study

The immunopathophysiological mechanisms underlying chronic inflammatory demyelinating polyneuropathy (CIDP) in an individual patient are largely unknown. Better understanding of these mechanisms may aid development of biomarkers and targeted therapies. Both B- and T-cell dominant mechanisms have been implicated. We therefore investigated whether B-cell and T-cell receptor (BCR/TCR) repertoires might function as immunological biomarkers in CIDP. In this prospective cohort study, we longitudinally sampled peripheral blood of CIDP patients in three different phases of CIDP: starting induction treatment (IT), starting withdrawal from IVIg maintenance treatment (MT), and patients in remission (R). BCR and TCR repertoires were analyzed using RNA based high throughput sequencing. In baseline samples, the number of total clones, the number of dominant BCR and TCR clones and their impact on the repertoire was similar for patients in the IT, MT, and remission groups compared with healthy controls. Baseline samples in the IT or MT did not predict treatment response or potential relapse at follow-up. Treatment responders in the IT group showed a potential IVIg-induced increase in the number of dominant BCR clones and their impact at follow-up (baseline1.0 [IQR 1.0-2.8] vs. 6 m 3.5 [0.3-6.8]; P < .05, Wilcoxon test). Although the BCR repertoire changed over time, the TCR repertoire remained robustly stable. We conclude that TCR and BCR repertoire distributions do not predict disease activity, treatment response or response to treatment withdrawal.

Treatment of CIDP

Chronic inflammatory demyelinating polyneuropathy is a disabling but treatable disorder. However, misdiagnosis is common, and it can be difficult to optimise its treatment. Various agents are used both for first and second line. First-line options are intravenous immunoglobulin, corticosteroids and plasma exchange. Second-line therapies may be introduced as steroid-sparing agents or as more potent escalation therapy. It is also important to consider symptomatic treatment of neuropathic pain and non-pharmacological interventions. We discuss the evidence for the various treatments and explain the practicalities of the different approaches. We also outline strategies for monitoring response and assessing the ongoing need for therapy.

Update on therapy of chronic immune-mediated neuropathies

Chronic immune-mediated neuropathies, including chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), neuropathies associated with monoclonal gammopathy, and multifocal motor neuropathy (MMN), are a group of disorders deemed to be caused by an immune response against peripheral nerve antigens. Several immune therapies have been reported to be variably effective in these neuropathies including steroids, plasma exchange, and high-dose intravenous (IVIg) or subcutaneous (SCIg) immunoglobulins. These therapies are however far from being invariably effective and may be associated with a number of side effects leading to the use of immunosuppressive agents whose efficacy has not been so far confirmed in randomized trials. More recently, new biological agents, such as rituximab, have proved to be effective in patients with neuropathy associated with IgM monoclonal gammopathy and are currently tested in CIDP.

French recommendations for the management of adult & pediatric chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare autoimmune disorder of the peripheral nervous system, primarily affecting the myelin sheath. The pathophysiology of CIDP is complex, involving both humoral and cellular immunity. The diagnosis of CIDP should be suspected in patients with symmetrical proximal and distal motor weakness and distal sensory symptoms of progressive onset, associated with decreased/abolished tendon reflexes. Treatments include intraveinous immunoglobulins, steroids and plasma exchange, with usually an induction phase followed by a maintenance therapy with progressive weaning. Treatment should be rapidly initiated to prevent axonal degeneration, which may compromise recovery. CIDP outcome is variable, ranging from mild distal paresthesiae to complete loss of ambulation. There have been several breakthroughs in the diagnosis and management of CIDP the past ten years, e.g. discovery of antibodies against the node of Ranvier, contribution of nerve ultrasound and magnetic resonance imaging to diagnosis, and demonstration of subcutaneous immunoglobulins efficiency. This led us to elaborate French recommendations for the management of adult & pediatric CIDP patients. These recommendations include diagnosis assessment, treatment, and follow-up.

Genetic biomarkers for intravenous immunoglobulin response in chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND AND PURPOSE

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a clinical and electrophysiological heterogeneous immune-mediated polyneuropathy. Intravenous immunoglobulin (IVIg), corticosteroids, and plasma exchange are proven effective treatments for CIDP. The clinical response to IVIg is variable between patients and currently unexplained. Finding biomarkers related to treatment response can help to understand the diversity of CIDP and personalise treatment choice.

METHODS

We investigated whether genetic variation between patients may explain some of these differences in treatment response. Based on previous publications, we selected six candidate genes that might affect immune and axonal functions, IVIg metabolism, and treatment response in CIDP. Genetic variants were assessed in 172 CIDP patients treated with at least one course of IVIg (2 g/kg). A response to IVIg was defined by ≥1 grade improvement on the modified Rankin Scale. Blood samples were tested for variations in CNTN2, PRF1, FCGRT, FCGR2B, GJB1, and SH2D2A genes.

RESULTS

In univariate analysis, patients with the FCGR2B promoter variant 2B.4/2B.1 responded more often to IVIg than patients with the 2B.1/2B.1 variant (odds ratio [OR] = 6.9, 95% confidence interval [CI] = 1.6-30; p = 0.003). Patients with the p.(Ala91Val) variant of PRF1 were less often IVIg responsive (OR = 0.34, 95% CI = 0.13-0.91; p = 0.038). In multivariate analysis, both PRF1 and FCGR2B showed discriminative ability to predict the chance of IVIg response (area under the curve = 0.67).

CONCLUSIONS

Variations in PRF1 and the promoter region of FCGR2B are associated with the response to IVIg in CIDP. These findings, which require validation, are a first step towards the understanding of the heterogeneity in the treatment response in CIDP.

Complications of Immunoglobulin Therapy and Implications for Treatment of Inflammatory Neuropathy: A Review

BACKGROUND

Intravenous Immunoglobulin (IVIg) forms a cornerstone of effective treatment for acute and chronic inflammatory neuropathies, with a class I evidence base in Guillain-Barré Syndrome (GBS), Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) and multifocal motor neuropathy (MMN). It is generally considered to be a safe therapy however there are several recognised complications which are reviewed in this article.

DISCUSSION AND CONCLUSION

Most adverse events are immediate and mild such as headache, fever and nausea although more serious immediate reactions such as anaphylaxis may rarely occur. Delayed complications are rare but may be serious, including thromboembolic events and acute kidney injury, and these and associated risk factors are also discussed. We emphasise the importance of safe IVIg administration and highlight practical measures to minimise complications of this therapy.

Current practice patterns in CIDP: A cross-sectional survey of neurologists in the United States

To evaluate how neurologists make decisions regarding chronic inflammatory demyelinating polyneuropathy (CIDP), we conducted a cross-sectional quantitative survey of 100 community neurologists in the United States. Only 13% cited using the European Federation of Neurological Societies/Peripheral Nerve Society guideline. In addition, variability in treatment approaches existed regarding the dose of IVIg used, the length of IVIg therapy before determining response, the outcome measures used to determine IVIg response, and the protocol for weaning off therapy. Forty-three percent reported giving doses that were lower than the recommended IVIg loading dose for CIDP. Many reported giving nonspecific patient education about the rationale of IVIg use and treatment duration. The finding that approximately half of community neurologists endorsed electrodiagnostic criteria that do not support CIDP diagnosis indicated difficulties relying heavily upon neurophysiologic studies in diagnostic guidelines. More education on CIDP diagnosis and treatment and a clear, actionable, clinically focused guideline would enhance best practices, particularly in the midst of high information flow and multiple guidelines.

Intravenous immunoglobulin for treatment of chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy in France: are daily practices in accordance with guidelines?

BACKGROUND AND PURPOSE

Chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN) are rare autoimmune diseases. Guidelines were published in 2010 for their diagnosis and treatment. In France, intravenous immunoglobulins (IVIGs) are mainly used for the first-line treatment. The burden of healthcare costs is often underlined but rarely studied. The aim of this survey was to compare to guidelines, the daily practice of French neurologists with IVIGs for CIDP and MMN treatment.

METHODS

This was a retrospective observational study consisting of an online questionnaire performed between March and May 2014. A total of 49 questionnaires were included, a quarter of which were from neurologists working in neuromuscular reference centers (NRCs).

RESULTS

A total of 182 patient case reports were studied. Patients were referred to an NRC for initial diagnosis in approximately 30% of cases in CIDP and 50% of cases in MMN. The initial management of IVIG (frequency, dose and duration) was not different between NRCs and non-NRCs. Guidelines were followed and neurologists were relatively at ease in diagnosing and treating patients.

CONCLUSIONS

This was the first national study to describe the implementation of the European Federation of Neurological Sciences/Peripheral Nerve Society guidelines in the daily management of IVIGs in patients with MMN and CIDP in France. Efforts are needed to improve long-term tailored treatment and home treatment to reduce economic costs.

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.

Intravenous immunoglobulin for maintenance treatment of chronic inflammatory demyelinating polyneuropathy: a multicentre, open-label, 52-week phase III trial

OBJECTIVE

Short-term efficacy of induction therapy with intravenous immunoglobulin (Ig) in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) is well established. However, data of previous studies on maintenance therapy were limited up to 24-week treatment period. We aimed to investigate the efficacy and safety of longer-term intravenous Ig therapy for 52 weeks.

METHODS

This study was an open-label phase 3 clinical trial conducted in 49 Japanese tertiary centres. 49 patients with CIDP who fulfilled diagnostic criteria were included. After an induction intravenous Ig therapy (0.4 g/kg/day for five consecutive days), maintenance dose intravenous Ig (1.0 g/kg) was given every 3 weeks for up to 52 weeks. The primary outcome measures were the responder rate at week 28 and relapse rate at week 52. The response and relapse were defined with the adjusted Inflammatory Neuropathy Cause and Treatment scale.

RESULTS

At week 28, the responder rate was 77.6% (38/49 patients; 95% CI 63% to 88%), and the 38 responders continued the maintenance therapy. At week 52, 4 of the 38 (10.5%) had a relapse (95% CI 3% to 25%). During 52 weeks, 34 (69.4%) of the 49 enrolled patients had a maintained improvement. Adverse events were reported in 94% of the patients; two patients (66-year-old and 76-year-old men with hypertension or diabetes) developed cerebral infarction (lacunar infarct with good recovery), and the other adverse effects were mild and resolved by the end of the study period.

CONCLUSIONS

Maintenance treatment with 1.0 g/kg intravenous Ig every 3 weeks is an efficacious therapy for patients with CIDP, and approximately 70% of them had a sustained remission for 52 weeks. Thrombotic complications should be carefully monitored, particularly in elderly patients with vascular risk factors.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT01824251).

Measuring disease activity and clinical response during maintenance therapy in CIDP: from ICE trial outcome measures to future clinical biomarkers

Some patients with chronic inflammatory demyelinating polyradiculoneuropathy who respond to initial intravenous immunoglobulin require repeated courses over prolonged periods of time; however, evidence to guide dosage and interval of intravenous immunoglobulin during maintenance therapy is limited. Optimizing treatment requires assessment of underlying disease activity and clinical outcome. Electrophysiological measures of demyelination, and clinical measures using handgrip strength and walking velocity promise to be particularly informative. Major advances in resolution and image processing have expanded clinical applications for ultrasound to include the study of peripheral nerves. Ultrasonography shows promise in diagnosing chronic inflammatory demyelinating polyradiculoneuropathy and distinguishing it from other conditions, providing first ever insight into gross pathology of peripheral nerves. Ultrasonography may also have a role in monitoring disease activity and treatment response.

Two years' long-term follow up in chronic inflammatory demyelinating polyradiculoneuropathy: efficacy of intravenous immunoglobulin treatment

BACKGROUND

Administration of intravenous immunoglobulins (IVIgs) is established for long-term treatment of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Prevention of secondary axonal loss going along with permanent clinical disability and muscular atrophy is a major aim in CIDP therapy. To assess long-term clinical efficacy of IVIg treatment despite heterogenous disease course and variable complaints reported by the patients, long-term electrophysiological monitoring was performed for systematic evaluation of therapeutic efficacy of IVIg.

METHODS

A total of 21 patients with CIDP treated with IVIg 1 g/kg bodyweight every 3-6 weeks were examined electrophysiologically every 12 months over a period of 2 years.

RESULTS

Assessment of clinical symptoms, using the Inflammatory Neuropathy Cause and Treatment (INCAT) and Hughes functional grading score (F-score) revealed improvement of motor and sensory symptoms over a period of 2 years. As electrophysiological results remained stable, IVIg treatment seems to be suitable to prevent axonal loss in CIDP.

CONCLUSIONS

This study confirms efficacy of IVIg as firstline therapy in CIDP. Doses and frequency of IVIg application should be adapted based on clinical evaluation and analysis of long-term electrophysiological findings.