Economic costs and quality of life in chronic inflammatory neuropathies in southeast England

Novel therapies in CIDP

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a heterogeneous but clinically well-described disease within circumscribed parameters. It is immunologically mediated through several poorly understood mechanisms. First-line therapies with steroids, intravenous immunoglobulin (IVIG) or plasma exchange are each effective in about two-thirds of patients. These treatments are seldom associated with complete resolution or cure, and often pose considerable practical, financial and medical implications.Our understanding of many of the key pathological processes in autoimmune diseases is expanding, and novel targeted therapeutics are being developed with promise in several autoimmune neurological disorders.This narrative review looks first at detailing key pathogenic mechanisms of disease in CIDP, followed by an in-depth description of potential novel therapies and the current evidence of their application in clinical practice.

Chronic inflammatory demyelinating polyneuropathy. A case description

Patients affected by chronic inflammatory demyelinating polyradiculoneuropathy require close follow up due to the neuronal demyelination along with axonal degeneration associated with the disease process, giving the opportunity to the medical team of adequating therapeutics and other medical interventions, according to the evolution of the symptoms, to prevent irreversible axonal degeneration.

Genetic analyses of inflammatory polyneuropathy and chronic inflammatory demyelinating polyradiculoneuropathy identified candidate genes

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare, immune-mediated disorder in which an aberrant immune response causes demyelination and axonal damage of the peripheral nerves. Genetic contribution to CIDP is unclear and no genome-wide association study (GWAS) has been reported so far. In this study, we aimed to identify CIDP-related risk loci, genes, and pathways. We first focused on CIDP, and 516 CIDP cases and 403,545 controls were included in the GWAS analysis. We also investigated genetic risk for inflammatory polyneuropathy (IP), in which we performed a GWAS study using FinnGen data and combined the results with GWAS from the UK Biobank using a fixed-effect meta-analysis. A total of 1,261 IP cases and 823,730 controls were included in the analysis. Stratified analyses by gender were performed. Mendelian randomization (MR), colocalization, and transcriptome-wide association study (TWAS) analyses were performed to identify associated genes. Gene-set analyses were conducted to identify associated pathways. We identified one genome-wide significant locus at 20q13.33 for CIDP risk among women, the top variant located at the intron region of gene CDH4. Sex-combined MR, colocalization, and TWAS analyses identified three candidate pathogenic genes for CIDP and five genes for IP. MAGMA gene-set analyses identified a total of 18 pathways related to IP or CIDP. Sex-stratified analyses identified three genes for IP among males and two genes for IP among females. Our study identified suggestive risk genes and pathways for CIDP and IP. Functional analyses should be conducted to further confirm these associations.

Use of Health Technology Assessment for the Continued Funding of Health Technologies: The Case of Immunoglobulins for the Management of Multifocal Motor Neuropathy

INTRODUCTION

Funding decisions for many health technologies occur without undergoing health technology assessment (HTA), in particular, without assessment of cost effectiveness (CE). Immunoglobulins in Australia are an interesting case study because they have been used for a long time for various rare disorders and their price is publicly available. Undertaking an HTA enables us to assess CE for an intervention for which there is limited clinical and economic evidence. This study presents a post-market review to assess the CE of immunoglobulins for the treatment of multifocal motor neuropathy (MMN) compared with best supportive care.

METHODS

A Markov model was used to estimate costs and quality-adjusted life-years (QALYs). Input sources included randomised controlled trials, single-arm studies, the Australian clinical criteria for MMN, clinical guidelines, previous Medical Services Advisory Committee (MSAC) reports and inputs from clinical experts. Sensitivity analyses were conducted to assess the uncertainty and robustness of the CE results.

RESULTS

The cost per patient of treating MMN with immunoglobulin was AU$275,853 versus AU$26,191when no treatment was provided, with accrued QALYs of 6.83 versus 6.04, respectively. The latter translated into a high incremental cost-effectiveness ratio (ICER) of AU$317,552/QALY. The ICER was most sensitive to the utility weights and the price of immunoglobulins. MSAC advised to continue funding of immunoglobulins on the grounds of efficacy, despite the high and uncertain ICER.

CONCLUSIONS

Beyond the ICER framework, other factors were acknowledged, including the high clinical need in a patient population for which there are no other active treatments available. This case study highlights the challenges of conducting HTA for already funded interventions, and the efficiency trade-offs required to fund effective high-cost therapies in rare conditions.

Cost of illness in inclusion body myositis: results from a cross-sectional study in Germany

BACKGROUND

Inclusion body myositis (IBM) is the most frequent type of myositis in elder patients with a slow chronic progression and refractory to treatment. Previous cost of illness (COI) studies in IBM used claims data to estimate direct costs in the US. No evidence exists globally on both direct and indirect costs in IBM from a societal perspective. We conducted a survey in patients registered in the German IBM patient registry. Self-developed items were used to assess the utilized healthcare resources and estimate the cost. The German Self-Administered Comorbidity Questionnaire (SCQ-D), the sIBM Physical Functioning Assessment (sIFA) and patient-reported measures for satisfaction and improvements in healthcare were applied for an explorative analysis.

RESULTS

In total, 82 patients completed the survey. We estimated the mean total annual per capita COI of US$102,682 (95% CI US$82,763-US$123,090) in 2021. 92.7% of the total COI were direct costs. Medical costs were similar to nonmedical costs, with substantial costs for pharmacotherapy and informal care. Depending on the prevalence estimate, the total national COI per year were US$42.7 million-US$213.7 million. Significant differences in total COI were identified for the degree of disability, marital and employment status (p < 0.05).

CONCLUSIONS

We identified remarkable and heterogenous cost in IBM. As informal care costs represented the most relevant cost driver, caregiver burden is a major factor in the patient journey. For the first time, comprehensive economic potentials were identified as a basis to improve the actual care situations and prioritizing future activities for research, pharmaceutical and digital product development as well as health politics.

Autologous haematopoietic stem cell transplantation for immune-mediated neurological diseases: what, how, who and why?

In carefully selected patients, autologous haematopoietic stem cell transplantation (HSCT) is a safe, highly effective and cost-saving treatment modality for treatment-resistant, and potentially treatment-naïve, immune-mediated neurological disorders. Although the evidence base has been growing in the last decade, limited understanding has led to confusion, mistrust and increasing use of health tourism. In this article, we discuss what autologous HSCT is, which immune-mediated conditions can be treated with it, how to select patients, what are the expected outcomes and potential adverse effects, and how cost-effective this treatment is.

A Budget Impact Model of Maintenance Treatment of Chronic Inflammatory Demyelinating Polyneuropathy with IgPro20 (Hizentra) Relative to Intravenous Immunoglobulin in the United States

BACKGROUND

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare, progressive autoimmune disease causing peripheral nervous system dysfunction. Guidelines recommend immunoglobulin (IG) therapy as an immunomodulatory agent in CIDP. Drawbacks and unmet needs with intravenous immunoglobulin (IVIG) include adverse effects and wear-off effects, along with the burden of administration based on site of care. Subcutaneous administration of Hizentra, a subcutaneous immunoglobulin (SCIG) reduces patient burden by allowing self-administration outside the hospital setting and has fewer adverse events (AEs).

OBJECTIVE

We aimed to compare the expected cost of treatment and the budget impact of Hizentra compared with IVIG for maintenance treatment of CIDP in the United States.

METHODS

A decision tree model was developed to estimate the expected budget impact of maintenance treatment with Hizentra for US stakeholders. The model adopts primarily a US integrated delivery network perspective and, secondarily, a commercial perspective over a 1-year time horizon. Pharmacy costs were based on a payment mix of average sales price (73%), wholesale acquisition cost (2%), and average wholesale price (25%). Costs in the model reflect 2022 US dollars. In accordance with the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) guidelines and recommendations for budget impact modeling, no discounting was performed. The PATH clinical study of Hizentra maintenance in CIDP was used to determine clinical inputs for relapse rates at initial assessment (24 weeks) and at 52 weeks for Hizentra. The ICE clinical study of Gamunex maintenance in CIDP was the basis of relapse rates for Gamunex (and other IVIGs). Literature-based estimates were obtained for infusion costs by site of care, costs of IVIG infusion-related complications, and significant IVIG AE rates. Hizentra AE rates from the US Hizentra prescribing information were assessed but were not included in the model as the AEs in CIDP were mild, easily treated, and self-limited. Sensitivity analyses and scenario analyses were conducted to evaluate variations from the base case.

RESULTS

The model showed that a Hizentra starting dose of 0.2 g/kg is expected to result in annual cost savings of US$32,447 per patient compared with IVIG. For a hypothetical 25-million-member plan, the budget impact of a 10% market share shift from IVIG to Hizentra is expected to result in savings of US$2,296,235.

CONCLUSION

This analysis projects that Hizentra is likely associated with favorable economic benefit compared with IVIG in managing CIDP.

Prevalence of chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy in two regions of Australia

INTRODUCTION/AIMS

Immune-mediated neuropathies such as chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN) produce significant disability and often require maintenance treatment. There is a paucity of epidemiological data on these conditions in Australia.

METHODS

We undertook a prevalence study of CIDP and MMN in North Queensland and Tasmania, coinciding with a national census. Diagnoses were classified against the diagnostic criteria of the European Federation of Neurological Societies/Peripheral Nerve Society. Case ascertainment was undertaken via multiple methods, including survey of local neurologists across public and private clinics, search of neurophysiology, neurology and hospital databases, search of admitted hospital database collections using ICD codes and through immunoglobulin therapy prescription lists.

RESULTS

The crude prevalence of CIDP was 5.00 per 100,000 (95% confidence interval [CI] 3.79-6.62) and the crude prevalence of MMN was 1.33 per 100,000 (95% CI 0.78-2.27). Prevalence was also investigated using National Blood Authority numbers of cases prescribed immunoglobulin therapy, indicating a CIDP prevalence of 5.72 per 100,000 (95% CI 4.41-7.43) and MMN prevalence of 1.94 per 100,000 (95% CI 1.24-3.03). There was no significant difference between these numbers and those calculated through access of patient records locally. There was no significant difference in prevalence between Tasmania and North Queensland for any category.

DISCUSSION

This study updates the prevalence of CIDP and MMN in Australia. Understanding the distribution of CIDP and MMN patients and their need for treatment is essential for future resource planning and to enable monitoring and coordination of therapies such as immunoglobulin.

Rare Neurological Diseases: an Overreview of Pathophysiology, Epidemiology, Clinical Features and Pharmacoeconomic Considerations in the Treating

Rare diseases (RD) are serious chronic diseases affecting small number of people compared to the general population. There are between 6000 and 8000 RDs, which affect about 400 million people worldwide. Drugs used for causal treatment of RDs are called orphan drugs. RDs bear great clinical and economic burden for patients, their families, healthcare systems and society overall. There are at least two reasons for the high cost of treatment of RDs. First, there is no causal therapy for majority of RDs, so exacerbations, complications, and hospitalizations in those patients are common. The second reason is high price of available orphan drugs, which are not cost-effective when traditional pharmacoeconomic evaluation is employed. The pharmacoeconomic aspect of the treatment of RDs is especially important in the field of neurology, since at least one fifth of all RDs is composed of neurological conditions. The aim of this paper was to provide a concise overview of the pathophysiological, epidemiological and clinical characteristics of some of the most important and common rare neurological diseases, with special reference to their impact on society and economy.

Clinical outcome of CIDP one year after start of treatment: a prospective cohort study

OBJECTIVE

To assess clinical outcome in treatment-naive patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

METHODS

We included adult treatment-naive patients participating in the prospective International CIDP Outcome Study (ICOS) that fulfilled the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) diagnostic criteria for CIDP. Patients were grouped based on initial treatment with (1) intravenous immunoglobulin (IVIg), (2) corticosteroid monotherapy or (3) IVIg and corticosteroids (combination treatment). Outcome measures included the inflammatory Rasch-built overall disability scale (I-RODS), grip strength, and Medical Research Council (MRC) sum score. Treatment response, treatment status, remissions (improved and untreated), treatment changes, and residual symptoms or deficits were assessed at 1 year.

RESULTS

Forty patients were included of whom 18 (45%) initially received IVIg, 6 (15%) corticosteroids, and 16 (40%) combination treatment. Improvement on ≥ 1 of the outcome measures was seen in 31 (78%) patients. At 1 year, 19 (48%) patients were still treated and fourteen (36%) patients were in remission. Improvement was seen most frequently in patients started on IVIg (94%) and remission in those started on combination treatment (44%). Differences between groups did not reach statistical significance. Residual symptoms or deficits ranged from 25% for neuropathic pain to 96% for any sensory deficit.

CONCLUSIONS

Improvement was seen in most patients. One year after the start of treatment, more than half of the patients were untreated and around one-third in remission. Residual symptoms and deficits were common regardless of treatment.

Cost-of-illness studies in rare diseases: a scoping review

Objective

The aim of this scoping review was to overview the cost-of-illness studies conducted in rare diseases.

Methods

We searched papers published in English in PubMed from January 2007 to December 2018. We selected cost-of-illness studies on rare diseases defined as those with prevalence lower than 5 per 10,000 cases. Studies were selected by one researcher and verified by a second researcher. Methodological characteristics were extracted to develop a narrative synthesis.

Results

We included 63 cost-of-illness studies on 42 rare diseases conducted in 25 countries, and 9 systematic reviews. Most studies (94%) adopted a prevalence-based estimation, where the predominant design was cross-sectional with a bottom-up approach. Only four studies adopted an incidence-based estimation. Most studies used questionnaires to patients or caregivers to collect resource utilisation data (67%) although an important number of studies used databases or registries as a source of data (48%). Costs of lost productivity, non-medical costs and informal care costs were included in 68%, 60% and 43% of studies, respectively.

Conclusion

This review found a paucity of cost-of-illness studies in rare diseases. However, the analysis shows that the cost-of-illness studies of rare diseases are feasible, although the main issue is the lack of primary and/or aggregated data that often prevents a reliable estimation of the economic burden.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01815-3.

Cost-of-illness studies in rare diseases: a scoping review

OBJECTIVE

The aim of this scoping review was to overview the cost-of-illness studies conducted in rare diseases.

METHODS

We searched papers published in English in PubMed from January 2007 to December 2018. We selected cost-of-illness studies on rare diseases defined as those with prevalence lower than 5 per 10,000 cases. Studies were selected by one researcher and verified by a second researcher. Methodological characteristics were extracted to develop a narrative synthesis.

RESULTS

We included 63 cost-of-illness studies on 42 rare diseases conducted in 25 countries, and 9 systematic reviews. Most studies (94%) adopted a prevalence-based estimation, where the predominant design was cross-sectional with a bottom-up approach. Only four studies adopted an incidence-based estimation. Most studies used questionnaires to patients or caregivers to collect resource utilisation data (67%) although an important number of studies used databases or registries as a source of data (48%). Costs of lost productivity, non-medical costs and informal care costs were included in 68%, 60% and 43% of studies, respectively.

CONCLUSION

This review found a paucity of cost-of-illness studies in rare diseases. However, the analysis shows that the cost-of-illness studies of rare diseases are feasible, although the main issue is the lack of primary and/or aggregated data that often prevents a reliable estimation of the economic burden.

The Cost Effectiveness of Immunoglobulin vs. Hematopoietic Stem Cell Transplantation for CIDP

Background: Intravenous immunoglobulin (IVIG) is effective as standard first line therapy for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), but some patients remain dependent on its long-term use. Recently, we have reported that autologous non-myeloablative hematopoietic stem cell transplantation (HSCT) is an effective second line therapy for CIDP. Objectives: To compare the cost of chronic IVIG vs. autologous HSCT (a one-time therapy), we collected data on patients with CIDP undergoing HSCT between 2017 and 2019. This was compared with published literature on the costs and efficacy defined by the Inflammatory Neuropathy Cause And Treatment (INCAT) disability score, Medical Research Council (MRC) sum score, hand grip strength, and SF-36 quality of life (QOL) for CIDP. Methods: Between 2017 and 2019, nineteen patients with chronic CIDP (mean disease treatment duration prior to HSCT of 6 years) underwent autologous HSCT with mean cost of $108,577 per patient (range $56,327-277,119, standard deviation $53,092). After HSCT, 80% of patients remain IVIG and immune treatment free for up to 5 years. In comparison, published cost of IVIG treatment in the USA for an average CIDP patient exceeds $136,000 per year. Despite remaining treatment free, HSCT demonstrated greater improvement in efficacy compared to immunoglobulins. Recommendations: Given the long-term treatment-free remission and better outcome measurements, autologous HSCT is more cost effective than long-term IVIG treatment in patients with chronic CIDP. However, costs will depend on patient selection, the HSCT regimen, and regional variations. Further analysis of the health economics, i.e., cost/outcome ratio, of HSCT as therapy for chronically IVIG dependent CIDP is warranted.

Systematic literature review of burden of illness in chronic inflammatory demyelinating polyneuropathy (CIDP)

Background

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare neurological disorder characterised by muscle weakness and impaired sensory function. The present study provides a comprehensive literature review of the burden of illness of CIDP.

Methods

Systematic literature search of PubMed, Embase, and key conferences in May 2019. Search terms identified studies on the epidemiology, humanistic burden, current treatment, and economic burden of CIDP published since 2009 in English.

Results

Forty-five full texts and nineteen conference proceedings were identified on the epidemiology (n = 9), humanistic burden (n = 7), current treatment (n = 40), and economic burden (n = 8) of CIDP. Epidemiological studies showed incidence and prevalence of 0.2–1.6 and 0.8–8.9 per 100,000, respectively, depending on geography and diagnostic criteria. Humanistic burden studies revealed that patients experienced physical and psychosocial burden, including impaired physical function, pain and depression. Publications on current treatments reported on six main types of therapy: intravenous immunoglobulins, subcutaneous immunoglobulins, corticosteroids, plasma exchange, immunosuppressants, and immunomodulators. Treatments may be burdensome, due to adverse events and reduced independence caused by treatment administration setting. In Germany, UK, France, and the US, CIDP economic burden was driven by direct costs of treatment and hospitalisation. CIDP was associated with indirect costs driven by impaired productivity.

Conclusions

This first systematic review of CIDP burden of illness demonstrates the high physical and psychosocial burden of this rare disease. Future research is required to fully characterise the burden of CIDP, and to understand how appropriate treatment can mitigate burden for patients and healthcare systems.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-09998-8) contains supplementary material, which is available to authorized users.

Evaluation of Quality of Life in Patients With Chronic Inflammatory Demyelinating Polyneuropathy in Iran

OBJECTIVES

In addition to the physical disability in chronic inflammatory demyelinating polyneuropathy (CIDP), various aspects of quality of life (QoL) are affected by the disease. Our goal was to evaluate the QoL in Iranian patients with CIDP and to study the association of clinical and demographic factors with QoL parameters.

METHODS

Twenty-six Iranian patients with CIDP were asked to complete a standardized Persian version of SF-36, and the association of demographic and functional parameters with QoL parameters was assessed.

RESULTS

Sex, living place, and income had no significant effect on QoL. Mean physical composite score was 37.7 ± 9.4, and mean mental composite score was 37.2 ± 15.2 that was lower than similar studies. There was a positive correlation between QoL and muscle strength of different muscle groups [hand (r = 0.41, P = 0.04); hip (r = 0.44, P = 0.02); and foot (r = 0.41, P = 0.04); total manual muscle testing (r = 0.46, P = 0.02)] and a significant negative correlation between the duration of illness and mean physical composite score (r = -0.61, P = 0.00).

CONCLUSIONS

Our patients achieved low scores in both the physical and mental aspects of QoL compared with other studies. We found a significant correlation between the physical domain of the SF-36 score and muscle strength of the hand, hip, and foot muscle group and with total manual muscle testing, suggesting that physical disability is the most crucial factor affecting QoL. Also, there was a significant negative association between the duration of the disease and the physical domain.

Chronic inflammatory demyelinating polyneuropathy: update on diagnosis, immunopathogenesis and treatment

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an immune-mediated neuropathy typically characterised by symmetrical involvement, and proximal as well as distal muscle weakness (typical CIDP). However, there are several 'atypical' subtypes, such as multifocal acquired demyelinating sensory and motor neuropathy (Lewis-Sumner syndrome) and 'distal acquired demyelinating symmetric neuropathy', possibly having different immunopathogenesis and treatment responses. In the absence of diagnostic and pathogenetic biomarkers, diagnosis and treatment may be difficult, but recent progress has been made in the application of neuroimaging tools demonstrating nerve hypertrophy and in identifying subgroups of patients who harbour antibodies against nodal proteins such as neurofascin and contactin-1. Despite its relative rarity, CIDP represents a significant economic burden, mostly due to costly treatment with immunoglobulin. Recent studies have demonstrated the efficacy of subcutaneous as well as intravenous immunoglobulin as maintenance therapy, and newer immunomodulating drugs can be used in refractory cases. This review provides an overview focusing on advances over the past several years.

Clinical and economic comparison of an individualised immunoglobulin protocol vs. standard dosing for chronic inflammatory demyelinating polyneuropathy

Background

The clinical and economic implications of an individualised intravenous immunoglobulin (IVIg) protocol for chronic inflammatory demyelinating polyneuropathy (CIDP) are unknown. Comparison with standard dosing regimens has not been performed.

Methods

We retrospectively studied 47 IVIg-treated subjects with CIDP over 4 years with an individualised, outcome-measured, dose-modifying protocol. We evaluated responder and remission rates, clinical improvement levels and dose requirements. We compared clinical benefits and costs with those reported with standard dosing at 1 g/kg every 3 weeks.

Results

The IVIg-responder rate was 83% and the 4-year remission rate was 25.6%. Mean IVIg dose requirements were 22.06 g/week (SD:15.29) in patients on ongoing therapy. Dose range was wide (5.83–80 g/week). Mean infusion frequency was every 4.34 weeks (SD:1.70) and infusion duration of 2.79 days (SD:1.15). Mean Overall Neuropathy Limitation Scale improvement was 2.54 (SD:1.89) and mean MRC sum score improvement of 12.23 (SD:7.17) in IVIg-responders. Mean modified-INCAT (Inflammatory Neuropathy Cause and Treatment) score improvement was similar (p = 0.47) and mean MRC sum score improvement greater (p < 0.001) in our cohort, compared to the IVIg-treated arm of the ICE Study. Mean drug costs were GBP 37,660/patient/year (€ 43,309) and mean infusion-related costs of GBP 17,115/patient/year (€ 19,682), totalling GBP 54,775/patient/year (€ 62,991). Compared to standard dosing using recorded weight, mean savings were of GBP 13,506/patient/year (€ 15,532). Compared to standard dosing using dosing weight, savings were of GBP 6,506/patient/year (€ 7,482).

Conclusion

Our results indicate that an individualised IVIg treatment protocol is clinically non-inferior and 10–25% more cost-effective than standard dosing regimens in CIDP.

The economic burden of CIDP in the United States: A case-control study

Background

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare neurological disorder of the peripheral nervous system. The economic burden of CIDP is not well understood.

Objectives

To assess the economic and clinical burden of CIDP and to compare the incremental burden relative to a matched control group without CIDP.

Methods

This retrospective case-control analysis was conducted using data from the IQVIA Real-World Data Adjudicated Claims. Adults newly diagnosed with CIDP between 7/1/2010 and 6/30/2014 were identified and direct matched to controls without CIDP. Baseline characteristics were assessed and compared over a 6-month pre-index period. Healthcare resource use, costs and clinical characteristics were assessed and compared over a 2-year follow-up. Total cost differences over the 2-year follow-up were compared between matched cohorts using a generalized estimating equation model.

Results

The final sample comprised a total of 790 cases matched to 790 controls. Over the 2-year follow-up, cases more frequently experienced neuropathic pain, back pain and osteoarthritis and more commonly utilized opioids, anti-convulsants and anti-depressants. Compared to controls, more cases had ≥1 hospitalization (26.2% vs. 9.0%), and cases had a higher mean number of outpatient prescription fills (62.8 vs. 32.0) and physician office visits (34.7 vs. 13.0) (all p<0.0001). Cases had 7.5x higher mean total costs ($116,330 vs. $15,586, p<0.0001). Important cost drivers were costs for outpatient ancillary, radiology and HCPCS drugs (mean $76,366 vs. $4,292) and costs for inpatient care (mean $16,357 vs. $2,862) (both p<0.0001). Among cases, CIDP therapy (inclusive of both outpatient pharmacy and medical claims) accounted for 51.2% of mean total costs. After further adjusting for baseline clinical characteristics, cases were associated with a 6.1x increase in total costs compared to controls (p<0.0001).

Conclusions

Our findings suggest a substantial clinical and economic burden among patients with CIDP relative to matched controls over a 2-year follow-up.

Immune-mediated neuropathies

Since the discovery of an acute monophasic paralysis, later coined Guillain-Barré syndrome, almost 100 years ago, and the discovery of chronic, steroid-responsive polyneuropathy 50 years ago, the spectrum of immune-mediated polyneuropathies has broadened, with various subtypes continuing to be identified, including chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN). In general, these disorders are speculated to be caused by autoimmunity to proteins located at the node of Ranvier or components of myelin of peripheral nerves, although disease-associated autoantibodies have not been identified for all disorders. Owing to the numerous subtypes of the immune-mediated neuropathies, making the right diagnosis in daily clinical practice is complicated. Moreover, treating these disorders, particularly their chronic variants, such as CIDP and MMN, poses a challenge. In general, management of these disorders includes immunotherapies, such as corticosteroids, intravenous immunoglobulin or plasma exchange. Improvements in clinical criteria and the emergence of more disease-specific immunotherapies should broaden the therapeutic options for these disabling diseases.

Costs of illness in chronic inflammatory demyelinating polyneuropathy in Germany

INTRODUCTION

Cost of illness studies are essential to estimate societal costs of chronic inflammatory demyelinating polyneuropathy (CIDP) and identify cost-driving factors.

METHODS

In total, 108 patients were recruited from 3 specialized neuroimmunological clinics. Costs were calculated for a 3-month period, including direct and indirect costs. The following outcomes were assessed: inflammatory neuropathy cause and treatment disability scale, Mini-Mental State Examination, Beck Depression Inventory, Charlson comorbidity index, EuroQol-5D, World Health Organization quality of life instrument, and socioeconomic status. Univariate and multivariate analyses were applied to identify cost-driving factors.

RESULTS

Total quarterly costs were €11,333. Direct costs contributed to 83% of total costs (€9,423), whereas indirect costs accounted for 17% (€1,910) of total costs. The cost of intravenous immunoglobulin (IVIg) was the main determinant of total costs (67%). Reduced health-related quality of life and depressive symptoms were identified as independent predictors of higher total costs.

DISCUSSION

CIDP is associated with high societal costs, mainly resulting from the cost of IVIg treatment. Muscle Nerve 58: 681-687, 2018.

A multicentre randomiSed controlled TRial of IntraVEnous immunoglobulin compared with standard therapy for the treatment of transverse myelitis in adults and children (STRIVE)

BACKGROUND

Transverse myelitis (TM) is an immune-mediated disorder of the spinal cord that affects adults and children and that causes motor, sensory and autonomic dysfunction. There is a prolonged recovery phase, which may continue for many years. Neuromyelitis optica (NMO) is an uncommon relapsing inflammatory central nervous system condition in which TM can be the first presenting symptom. As TM and NMO affect many patients in the prime of their working life, the disorder can impose a significant demand on health resources. There are currently no robust controlled trials in children or adults to inform the optimal treatment of TM. However, treatment with intravenous immunoglobulin (IVIG) is being effectively used in the management of a range of neurological conditions. Although other interventions such as plasma exchange (PLEX) in addition to intravenous (IV) methylprednisolone therapy can be beneficial in TM, PLEX is costly and technically challenging to deliver in the acute setting. IVIG is more readily accessible and less costly.

OBJECTIVE

To evaluate whether additional and early treatment with IVIG is of extra benefit in TM compared with standard therapy with IV steroids.

DESIGN

A multicentre, single-blind, parallel-group randomised controlled trial of IVIG compared with standard therapy for the treatment of TM in adults and children.

PARTICIPANTS

Patients aged ≥ 1 year diagnosed with either acute first-onset TM or first presentation of NMO. Target recruitment was 170 participants (85 participants per arm).

INTERVENTIONS

Participants were randomised 1 : 1 to treatment with IV methylprednisolone only or treatment with IV methylprednisolone plus 2 g/kg of IVIG in divided doses within 5 days of the first commencement of steroid therapy.

MAIN OUTCOME MEASURES

Primary outcome measure - American Spinal Injury Association (ASIA) Impairment Scale at 6 months post randomisation, with a good outcome defined by a two-grade change. Secondary and tertiary outcome measures - ASIA motor and sensory scales, Expanded Disability Status Scale, health outcome, quality of life, Client Service Receipt Inventory and International Spinal Cord Injury Pain, Bladder and Bowel Basic Data Sets.

RESULTS

In total, 26 participants were screened and two were randomised into the study. With the limited sample size, treatment effect could not be determined. However, we identified barriers to accrual that included strict inclusion criteria, the short enrolment window, challenges associated with the use of the ASIA Impairment Scale as an outcome measure and estimation of the incidence of TM.

CONCLUSIONS

The study did not reach the end point and the effect of IVIG in TM/NMO could not be determined. Investigators should be aware of the potential challenges associated with carrying out a rare disease trial with a short enrolment window. The study question is one that still necessitates investigation. Preliminary work to ameliorate the effect of the barriers encountered in this study is vital.

TRIAL REGISTRATION

EudraCT 2014-002335-34, ClinicalTrials.gov NCT02398994 and Current Controlled Trials ISRCTN12127581.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 31. See the NIHR Journals Library website for further project information. Funding was also received from Biotest AG, Germany (supply of IVIG) and the Transverse Myelitis Society (excess research cost to facilitate study initiation).

Home versus hospital immunoglobulin treatment for autoimmune neuropathies: A cost minimization analysis

Background

Prior clinical trials have suggested that home-based Ig treatment in multifocal motor neuropathy (MMN) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and its variant Lewis-Sumner syndrome (LSS) is safe and effective and is less costly than hospital-administered intravenous immunoglobulin (IVIg).

Methods

A French prospective, dual-center, cost minimization analysis was carried out to evaluate IVIg administration (5% concentrated) at home versus in hospital with regard to costs, patients' autonomy, and patients' quality of life. The primary endpoint was the overall cost of treatment, and we adopted the perspective of the payer (French Social Health Insurance).

Results

Twenty-four patients aged 52.3 (12.2) years were analyzed: nine patients with MMN, eight with CIDP, and seven with LSS. IVIg (g/kg) dosage was 1.51 ± 0.43 in hospital and 1.52 ± 0.4 at home. Nine-month total costs per patient extrapolated to 1 year of treatment were €48,189 ± 26,105 versus €91,798 ± 51,125 in the home and hospital groups, respectively (p < .0001). The most frequently reported factors for choosing home treatment were the good tolerance and absence of side effects of IVIg administration, as well as a good understanding of the advantages and drawbacks of home treatment (75% of respondents). The mRankin scores before and after switch to home treatment were 1.61 ± 0.72 and 1.36 ± 0.76, respectively (p = .027).

Discussion

The switch from hospital-based to home-based IVIg treatment for patients with immune neuropathy represents potentially significant savings in the management of the disease.

Neuromuscular disease-specific questionnaire to assess quality of life in patients with chronic inflammatory demyelinating polyradiculoneuropathy

To date, generic questionnaires have been used to investigate quality of life (QoL) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients. Although these measures are very useful, they are not usually precise enough to measure all specific characteristics of the disease. Our aim was to investigate QoL using the neuromuscular disease-specific questionnaire (individualized neuromuscular quality of life, INQoL) in a large cohort of patients with CIDP. Our study comprised 106 patients diagnosed with CIDP. INQoL questionnaire, Medical Research Council (MRC) sum score, Inflammatory Neuropathy Cause and Treatment (INCAT) disability score, Visual Analogue Pain Scale, Beck Depression Inventory, and Krupp's Fatigue Severity Scale were used in our study. Physical domains of INQoL were more affected than mental, and the overall score was 57 ± 25. Significant predictors of higher INQoL score in our patients with CIDP were severe fatigue (β = 0.35, p < 0.01), higher INCAT disability score at time of testing (β = 0.29, p < 0.01), and being unemployed/retired (β = 0.22, p < 0.05). QoL was reduced in our cohort of CIDP patients, which was more pronounced in physical segments. Patients with fatigue, more severe disability, and unemployed/retired need special attention of neurologists because they could be at greater risk to have worse QoL.

The Epidemiology of Neuromuscular Diseases

Neuromuscular disorders as a group are linked by anatomy with significant differences in pathogenetic mechanisms, clinical expression, and time course of disease. Each neuromuscular disease is relatively uncommon, yet causes a significant burden of disease socioeconomically. Epidemiologic studies in different global regions have demonstrated certain neuromuscular diseases have increased incidence and prevalence rates over time. Understanding differences in global epidemiologic trends will aid clinical research and policies focused on prevention of disease. There is a critical need to understand the global impact of neuromuscular diseases using metrics currently established for communicable and noncommunicable diseases.

Regarding the past, what is the trial you have always been dreaming of in CIDP?

Chronic inflammatory demyelinating polyradiculoneuropathy is an orphan disease of poorly understood cause. While first line treatments with corticosteroids, intravenous immunoglobulin and plasma exchange have at least short-term efficacy, no trial has shown that immunosuppressants work. In our dream, we will take advantage of the recently improved EU regulations to launch a Europe wide trial which will investigate the cause of the disease. It will compare three parallel groups, the anti-B cell agent rituximab, the anti-T cell agent abatacept and usual care. The trial will not be blinded and the design will be very simple. The primary outcome measure will be improvement from baseline of the overall neuropathy limitations scale (ONLS) score by 1 or more grades at 12 weeks without increase in concomitant corticosteroids or IVIg or use of plasma exchange. There will be an option to substitute improvement in the Rasch-built overall disability scale depending on future experience with that scale as the primary outcome measure. The trial will require 3 groups of 60 participants to detect an increase from 20% in the usual care group to 30% with one of the other agents with a power of 90% and P-value of 5%. It will be larger than any trial of an immunosuppressant agent so far performed in CIDP. However, recruitment will be easier because inclusion criteria will be broad and allow randomisation of any patient in whom their neurologist wishes to introduce an immunosuppressant. Avoidance of blinding and use of simple monitoring with facetime will simplify running the trial and reduce expense. The trial will follow participants and measure outcomes at 12 months. Other outcomes will consist only of grip strength, time to walk 10 m and Euroqol, the last allowing us to estimate the cost per QALY of rituximab or abatacept. Even including central analysis of key biomarkers, the trial will only cost 3 million euros, a fraction of the cost of the usual phase III pharmaceutical company trial.

Sialylated IgG-Fc: a novel biomarker of chronic inflammatory demyelinating polyneuropathy

OBJECTIVE

Sialylation in Fc portion of IgG plays a crucial role in the pathogenesis of autoimmune diseases and the working mechanism of intravenous immunoglobulin (IVIG). We aim to test whether IgG-Fc sialylation is a biomarker of disease activity for chronic inflammatory demyelinating polyneuropathy (CIDP).

METHODS

By using specific lectins for sialylation, galactosylation and agalactosylation, lectin-enzyme assay and lectin blotting with pretreatment of IgG degradating enzyme of Streptococcus pyogenes were performed to compare the glycosylation levels of serum IgG-Fc (1) between patients of untreated CIDP (n=107) and normal control subjects (n=27), (2) among patients with untreated CIDP of different clinical severities and (3) before and after IVIG treatment of patients with CIDP (n=12).

RESULTS

Sialylation and galactosylation of IgG-Fc were significantly reduced in patients with CIDP than normal control subjects (p=0.003 and 0.033, respectively), whereas agalactosylation was increased in CIDP (p=0.21). Ratios of sialylated/agalactosylated IgG-Fc levels were significantly reduced in CIDP (p<0.001) and inversely related to disease severity (p=0.044). After IVIG treatment, levels of sialylated IgG-Fc significantly increased (p=0.003).

CONCLUSIONS

Sialylation of IgG-Fc is reduced in CIDP. Its level correlated with clinical severity and increased after IVIG treatment. Sialylated as well as ratio of sialylated/agalactosylated IgG-Fc could be new measures to monitor the disease severity and treatment status in CIDP.

Long-term immunoglobulin therapy for chronic inflammatory demyelinating polyradiculoneuropathy

Immunoglobulins are an effective but expensive treatment for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Although the goal is to improve function, use of functional scales to monitor therapy is not widespread. Limited recent evidence suggests that doses lower than those used traditionally may be as effective. There are no proven correlations of effective dose with weight, disease severity, or duration. The clinical course of CIDP is heterogeneous and includes monophasic forms and complete remissions. Careful monitoring of immunoglobulin use is necessary to avoid overtreatment. Definitive evidence for immunoglobulin superiority over steroids is lacking. Although latest trial evidence favors immunoglobulins over steroids, the latter may result in higher remission rates and longer remission periods. This article addresses the appropriateness of first-line, high-dose immunoglobulin treatment for CIDP and reviews important clinical questions regarding the need for long-term therapy protocols, adequate monitoring, treatment withdrawal, and consideration of corticosteroids as an alternative to immunoglobulin therapy.

New insights into the management of chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and its variants can be challenging to diagnose and treat. A combination of clinical, electrophysiological and laboratory features is often required to reach a diagnosis. New data are emerging about potential biomarkers and factors that may indicate treatment needs in individual patients. High-quality evidence exists for the efficacy of intravenous immunoglobulin (IVIG) in the treatment of CIDP, including quality of life (QoL) benefits. Besides pharmacological treatment, psychological factors must also be addressed to improve patients' QoL. Home-based IVIG infusion therapy is currently a well-established approach in some countries. A 6-month pilot study conducted in Ontario, Canada, provided proof of safety and patient acceptance of home-based IVIG therapy, although some logistical issues emerged.

Treatment of chronic inflammatory demyelinating polyneuropathy: from molecular bases to practical considerations

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an autoimmune disease of the peripheral nervous system, in which both cellular and humoral immune responses are involved. The disease is clinically heterogeneous with some patients displaying pure motor form and others also showing a variable degree of sensory dysfunction; disease evolution may also differ from patient to patient, since monophasic, progressive, and relapsing forms are reported. Underlying such clinical variability there is probably a broad spectrum of molecular dysfunctions that are and will be the target of therapeutic strategies. In this review we first explore the biological bases of current treatments and subsequently we focus on the practical management that must also take into account pharmacoeconomic issues.