Alemtuzumab in the treatment of IVIG-dependent chronic inflammatory demyelinating polyneuropathy

Classical Complement Pathway Inhibition in a "Human-On-A-Chip" Model of Autoimmune Demyelinating Neuropathies

Chronic autoimmune demyelinating neuropathies are a group of rare neuromuscular disorders with complex, poorly characterized etiology. Here we describe a phenotypic, human-on-a-chip (HoaC) electrical conduction model of two rare autoimmune demyelinating neuropathies, chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN), and explore the efficacy of TNT005, a monoclonal antibody inhibitor of the classical complement pathway. Patient sera was shown to contain anti-GM1 IgM and IgG antibodies capable of binding to human primary Schwann cells and induced pluripotent stem cell derived motoneurons. Patient autoantibody binding was sufficient to activate the classical complement pathway resulting in detection of C3b and C5b-9 deposits. A HoaC model, using a microelectrode array with directed axonal outgrowth over the electrodes treated with patient sera, exhibited reductions in motoneuron action potential frequency and conduction velocity. TNT005 rescued the serum-induced complement deposition and functional deficits while treatment with an isotype control antibody had no rescue effect. These data indicate that complement activation by CIDP and MMN patient serum is sufficient to mimic neurophysiological features of each disease and that complement inhibition with TNT005 was sufficient to rescue these pathological effects and provide efficacy data included in an investigational new drug application, demonstrating the model's translational potential.

Immunoglobulin and Monoclonal Antibody Therapies in Guillain-Barré Syndrome

Guillain-Barré syndrome (GBS) is an acute autoimmune polyradiculoneuropathy affecting 1-2 subjects per 100,000 every year worldwide. It causes, in its classic form, symmetric weakness in the proximal and distal limb muscles with common involvement of the cranial nerves, particularly facial weakness. Respiratory function is compromised in a case in four. Randomised controlled trials have demonstrated the benefit of therapeutic plasma exchange in hastening time to recovery. Intravenous immunoglobulin was subsequently shown to be as efficacious as plasma exchange in adult subjects. In children, few trials have shown the benefit of intravenous immunoglobulin versus supportive care. Pharmacokinetic studies suggested a relationship between increase in immunoglobulin G level post-infusion and outcome, implying administration of larger doses may be beneficial in subjects with poor prognosis. However, a subsequent trial of a second dose of immunoglobulin in such subjects failed to show improved outcome, while demonstrating a higher risk of thromboembolic side-effects. Monoclonal antibody therapy has more recently been investigated for GBS, after multiple studies in animal models, with different agents and variable postulated mechanisms of action. Eculizumab, a humanised monoclonal antibody against the complement protein C5, was tested in in two randomised, double-blind, placebo-controlled phase 2 trials. Neither showed benefit versus immunoglobulins alone on disability level at 4 weeks, although one study importantly suggested possible, clinically highly relevant, late effects on normalising function. A phase 3 trial is in progress. Preliminary results of a placebo-controlled ongoing study of ANX005, a humanised recombinant antibody against C1q inhibiting the complement cascade, have been promising.

Potential therapeutic strategies in chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an autoimmune neuropathy involving peripheral nerve and nerve roots. The pathological hallmark of CIDP is macrophage-induced demyelination. Antibodies against nerve fibers, complement decomposition, abnormalities in plasma and cerebrospinal fluid cytokine profile, and changes of peripheral blood cell proportion were also reported in CIDP patients. These findings in immunopathology provide support for the introduction of potential therapeutic options for the treatment of CIDP. In this review, we systematically listed the potential therapeutic strategies targeting different components of the immune system by comparing the treatment of other autoimmune inflammatory diseases of the nervous system. Several ongoing clinical trials will assess the efficacy and safety of potential CIDP treatments.

European Academy of Neurology/Peripheral Nerve Society guideline on diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy: Report of a joint Task Force-Second revision

OBJECTIVE

To revise the 2010 consensus guideline on chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

METHODS

Seventeen disease experts, a patient representative, and two Cochrane methodologists constructed 12 Population/Intervention/Comparison/Outcome (PICO) questions regarding diagnosis and treatment to guide the literature search. Data were extracted and summarized in GRADE summary of findings (for treatment PICOs) or evidence tables (for diagnostic PICOs).

RESULTS

Statements were prepared according to the GRADE Evidence-to-Decision frameworks. Typical CIDP and CIDP variants were distinguished. The previous term "atypical CIDP" was replaced by "CIDP variants" because these are well characterized entities (multifocal, focal, distal, motor, or sensory CIDP). The levels of diagnostic certainty were reduced from three (definite, probable, possible CIDP) to only two (CIDP and possible CIDP), because the diagnostic accuracy of criteria for probable and definite CIDP did not significantly differ. Good Practice Points were formulated for supportive criteria and investigations to be considered to diagnose CIDP. The principal treatment recommendations were: (a) intravenous immunoglobulin (IVIg) or corticosteroids are strongly recommended as initial treatment in typical CIDP and CIDP variants; (b) plasma exchange is strongly recommended if IVIg and corticosteroids are ineffective; (c) IVIg should be considered as first-line treatment in motor CIDP (Good Practice Point); (d) for maintenance treatment, IVIg, subcutaneous immunoglobulin or corticosteroids are recommended; (e) if the maintenance dose of any of these is high, consider either combination treatments or adding an immunosuppressant or immunomodulatory drug (Good Practice Point); and (f) if pain is present, consider drugs against neuropathic pain and multidisciplinary management (Good Practice Point).

European Academy of Neurology/Peripheral Nerve Society guideline on diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy: Report of a joint Task Force-Second revision

To revise the 2010 consensus guideline on chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Seventeen disease experts, a patient representative, and two Cochrane methodologists constructed 12 Population/Intervention/Comparison/Outcome (PICO) questions regarding diagnosis and treatment to guide the literature search. Data were extracted and summarized in GRADE summary of findings (for treatment PICOs) or evidence tables (for diagnostic PICOs). Statements were prepared according to the GRADE Evidence-to-Decision frameworks. Typical CIDP and CIDP variants were distinguished. The previous term "atypical CIDP" was replaced by "CIDP variants" because these are well characterized entities (multifocal, focal, distal, motor, or sensory CIDP). The levels of diagnostic certainty were reduced from three (definite, probable, possible CIDP) to only two (CIDP and possible CIDP), because the diagnostic accuracy of criteria for probable and definite CIDP did not significantly differ. Good Practice Points were formulated for supportive criteria and investigations to be considered to diagnose CIDP. The principal treatment recommendations were: (a) intravenous immunoglobulin (IVIg) or corticosteroids are strongly recommended as initial treatment in typical CIDP and CIDP variants; (b) plasma exchange is strongly recommended if IVIg and corticosteroids are ineffective; (c) IVIg should be considered as first-line treatment in motor CIDP (Good Practice Point); (d) for maintenance treatment, IVIg, subcutaneous immunoglobulin or corticosteroids are recommended; (e) if the maintenance dose of any of these is high, consider either combination treatments or adding an immunosuppressant or immunomodulatory drug (Good Practice Point); and (f) if pain is present, consider drugs against neuropathic pain and multidisciplinary management (Good Practice Point).

Dramatic clinical response to ultra-high dose IVIg in otherwise treatment resistant inflammatory neuropathies

BACKGROUND

Intravenous immunoglobulin (IVIg) has short and long-term efficacy in both chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy with conduction block (MMNCB). There is potential for under and over-treatment if trial regimens are strictly adhered to in clinical practice where titrating dose to clinical response is recommended.

METHODS

We report the response to high-dose IVIg (>2 g/kg/6 weeks) in a subgroup of patients with definite CIDP or MMNCB who were unresponsive to 'usual' dosing. IVIg frequency and dosing was determined for each individual by subjective and objective outcome measures for impairment, grip strength, and activity and participation.

RESULTS

Six patients (three with chronic inflammatory demyelinating polyneuropathy (CIDP), three with MMN) were included. Two patients (one CIDP and one MMNCB) returned to full-time work on fractionated IVIg doses of 5 g/kg/month and 9 g/kg/month. Patient three (CIDP) failed numerous other immunosuppressants but responded to short-term fractionated 4 g/kg/month of IVIg. Patient four has severe, refractory, childhood-onset CIDP, remains stable but dependent currently on 6.9 g/kg/month of IVIg. Patients five and six, both with MMNCB, required short term 4.5-5 g/kg/month to recover significant bilateral hand strength. No IVIg-related adverse events occurred in any individual.

CONCLUSIONS

These six cases demonstrate the safety and effectiveness of a treatment approach that includes individualised but evidence-based clinical assessment and, when necessary, high-doses of IVIg to restore patients' strength and ability to participate in activities of daily activities. Careful patient selection is important.

Inflammatory polyradiculoneuropathies: Clinical and immunological aspects, current therapies, and future perspectives

Inflammatory polyradiculoneuropathies are heterogeneous disorders characterized by immune-mediated leukocyte infiltration of peripheral nerves and nerve roots leading to demyelination or axonal degeneration or both. Inflammatory polyradiculoneuropathies can be divided into acute and chronic: Guillain–Barré syndrome and chronic inflammatory demyelinating polyneuropathy and their variants. Despite major advances in immunology and molecular biology have been made in the last years, the pathogenesis of these disorders is not completely understood. This review summarizes the current literature of the clinical features and pathogenic mechanisms of inflammatory polyradiculoneuropathies and focuses on current therapies and new potential treatment for the future.

Progress in Hematopoietic Stem Cell Transplantation for CIDP

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a kind of autoimmune-mediated inflammation and demyelinating disease. The etiology is mainly related to autoimmune dysfunction. The conventional treatments of CIDP have relied on immunomodulation and inhibition therapies such as adrenal cortex hormone, intravenous immunoglobulin (IVIg) and plasma exchange. Hematopoietic stem cell transplantation (HSCT) is known as a novel therapy for autoimmune disorders, which provides the chance to cure CIDP. More than 70 patients with refractory CIDP have received HSCT. The clinical symptoms and electrophysiological examination results of most patients have been improved. However, the treatment still has risks. This review describes the pathogenesis of CIDP and the current conventional treatments, and highlights the application of HSCT in CIDP, including its efficacy and safety.

Repurposing multiple sclerosis drugs: a review of studies in neurological and psychiatric conditions

Treatment options for multiple sclerosis (MS) have improved in the past 20 years, with new oral disease-modifying drugs and monoclonal antibodies becoming available. The success seen with these drugs in MS, and their various mechanisms of action, has led to them being investigated in other neurological and psychiatric disorders. This review article summarises the ongoing and completed studies of MS drugs in neurological and psychiatric conditions other than MS. The most promising results are for interferon beta in human T cell leukaemia virus 1 associated myelopathy/tropical spastic paraparesis and glioma, and for fingolimod in acute ischaemic stroke and intracerebral haemorrhage. The coming years could see the arrival of exciting new therapies for disorders that neurologists have historically found difficult to treat and that represent a significant unmet clinical need.

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.

Novel pathomechanisms in inflammatory neuropathies

Inflammatory neuropathies are rare autoimmune-mediated disorders affecting the peripheral nervous system. Considerable progress has recently been made in understanding pathomechanisms of these disorders which will be essential for developing novel diagnostic and therapeutic strategies in the future. Here, we summarize our current understanding of antigenic targets and the relevance of new immunological concepts for inflammatory neuropathies. In addition, we provide an overview of available animal models of acute and chronic variants and how new diagnostic tools such as magnetic resonance imaging and novel therapeutic candidates will benefit patients with inflammatory neuropathies in the future. This review thus illustrates the gap between pre-clinical and clinical findings and aims to outline future directions of development.

Unconventional treatments for chronic inflammatory demyelinating polyneuropathy

This article focuses on the unconventional treatments used in chronic inflammatory demyelinating polyneuropathy (CIDP). First line, evidence-based treatments for CIDP include corticosteroids, immunoglobulins and plasma exchanges. Several unproven treatments are however given in treatment-refractory disease or to reduce requirements in validated therapies for reasons of side effects/practical delivery/cost. Despite methodological issues, IFN-α, azathioprine and methotrexate have not been shown to be useful in randomized controlled trials. Cyclophosphamide, rituximab and, as final resort in highly selected cases, hematopoietic stem cell transplant may be options considered in severely disabled refractory patients. Debatably, azathioprine, methotrexate, cyclosporine and mycophenolate mofetil are still occasionally used, among others, in milder disease. Physical therapy may be of benefit in CIDP but is not systematically considered as an integral part of management strategies. Current literature relating to unconventional therapies in CIDP is reviewed here and the possible avenues that require consideration in severe refractory disease and less disabling forms are discussed.

Lymphocyte antigens targetable by monoclonal antibodies in non-systemic vasculitic neuropathy

OBJECTIVE

To identify the most relevant antigens for monoclonal antibodies in lymphocytic infiltrates in non-systemic vasculitic neuropathy (NSVN).

BACKGROUND

Current immunosuppressive treatment for NSVN is insufficient. Monoclonal antibodies might be a treatment option, but the expression profile for targetable antigens on lymphocytic infiltrates in NSVN is unknown.

METHODS

Sural nerve biopsies from a cohort of patients with NSVN were immunohistochemically studied for the expression of potential candidate antigens in perivascular and intramural lymphocytic infiltrates and correlated with neurological and electrophysiological parameters. 20 patients with treatment naïve NSVN and 5 patients with idiopathic axonal neuropathy were included.

RESULTS

The CD52, BAFF and CD49d antigens were expressed in epineurial, perivascular or intramural lymphocytes of all (20/20) patients. CD52 was most prominently expressed in 21.49% of all inflammatory infiltrates. BAFF and CD49d were detected in 11.25% and 10.99% of these lymphocytes, respectively. The CD20, CD25 and CD126 antigens were found less frequently and at low levels only (CD20: 10/20 patients, 5.84% of lymphocytes; CD25: 17/20 patients, 5.22% of lymphocytes; CD126: 3/20 patients, 0.15% of lymphocytes).

CONCLUSION

This is the first study in NSVN that identifies antigens expressed by pathogenic lymphocytes, which are potential targets for future monoclonal antibody treatment. Our data suggest that NSVN is amenable to monoclonal antibodies and, moreover, that targeting CD52 may be particularly promising. Our results strongly warrant future clinical trials in NSVN with monoclonal antibodies.

Immunomodulatory treatment other than corticosteroids, immunoglobulin and plasma exchange for chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a disease that causes progressive or relapsing and remitting weakness and numbness. It is probably caused by an autoimmune process. Immunosuppressive or immunomodulatory drugs would be expected to be beneficial. This review was first published in 2003 and has been updated most recently in 2016.

OBJECTIVES

To assess the effects of immunomodulatory and immunosuppressive agents other than corticosteroids, immunoglobulin, and plasma exchange in CIDP.

SEARCH METHODS

On 24 May 2016, we searched the Cochrane Neuromuscular Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 4) in the Cochrane Library, MEDLINE, Embase, CINAHL, and LILACS for completed trials, and clinical trial registers for ongoing trials. We contacted the authors of the trials identified and other disease experts seeking other published and unpublished trials.

SELECTION CRITERIA

We sought randomised and quasi-randomised trials of all immunosuppressive agents, such as azathioprine, cyclophosphamide, methotrexate, ciclosporin, mycophenolate mofetil, and rituximab, and all immunomodulatory agents, such as interferon (IFN) alfa and IFN beta, in participants fulfilling standard diagnostic criteria for CIDP. We included all comparisons of these agents with placebo, another treatment, or no treatment.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We wanted to measure the change in disability after one year as our primary outcome. Our secondary outcomes were change in disability after four or more weeks (from randomisation); change in impairment after at least one year; change in maximum motor nerve conduction velocity and compound muscle action potential amplitude after one year; and for participants who were receiving corticosteroids or intravenous immunoglobulin (IVIg), the amount of this medication given during at least one year after randomisation. Participants with one or more serious adverse events during the first year was also a secondary outcome.

MAIN RESULTS

Four trials fulfilled the selection criteria: one of azathioprine (27 participants), two of IFN beta-1a (77 participants in total) and one of methotrexate (60 participants). The risk of bias was considered low in the trials of IFN beta-1a and methotrexate but high in the trial of azathioprine. None of the trials showed significant benefit in any of the outcomes selected by their authors. The results of the outcomes which approximated most closely to the primary outcome for this review were as follows.In the azathioprine trial there was a median improvement in the Neuropathy Impairment Scale (scale range 0 to 280) after nine months of 29 points (range 49 points worse to 84 points better) in the azathioprine and prednisone treated participants compared with 30 points worse (range 20 points worse to 104 points better) in the prednisone alone group. There were no reports of adverse events.In a cross-over trial of IFN beta-1a with 20 participants, the treatment periods were 12 weeks. The median improvement in the Guy's Neurological Disability Scale (range 1 to 10) was 0.5 grades (interquartile range (IQR) 1.8 grades better to zero grade change) in the IFN beta-1a treatment period and 0.5 grades (IQR 1.8 grades better to 1.0 grade worse) in the placebo treatment period. There were no serious adverse events in either treatment period.In a parallel group trial of IFN beta-1a with 67 participants, none of the outcomes for this review was available. The trial design involved withdrawal from ongoing IVIg treatment. The primary outcome used by the trial authors was total IVIg dose administered from week 16 to week 32 in the placebo group compared with the IFN beta-1a groups. This was slightly but not significantly lower in the combined IFN beta-1a groups (1.20 g/kg) compared with the placebo group (1.34 g/kg, P = 0.75). There were four participants in the IFN beta-1a group and none in the placebo group with one or more serious adverse events, risk ratio (RR) 4.50 (95% confidence interval (CI) 0.25 to 80.05).The methotrexate trial had a similar design involving withdrawal from ongoing corticosteroid or IVIg treatment. At the end of the trial (approximately 40 weeks) there was no significant difference in the change in the Overall Neuropathy Limitations Scale, a disability scale (scale range 0 to 12), the median change being 0 (IQR -1 to 0) in the methotrexate group and 0 (IQR -0.75 to 0) in the placebo group. These changes in disability might have been confounded by the reduction in corticosteroid or IVIg dose required by the protocol. There were three participants in the methotrexate group and one in the placebo with one or more serious adverse events, RR 3.56 (95% CI 0.39 to 32.23).

AUTHORS' CONCLUSIONS

Low-quality evidence from randomised trials does not show significant benefit from azathioprine or interferon beta-1a and moderate-quality evidence from one randomised trial does not show significant benefit from a relatively low dose of methotrexate for the treatment of CIDP. None of the trials was large enough to rule out small or moderate benefit. The evidence from observational studies is insufficient to avoid the need for randomised controlled trials to discover whether these drugs are beneficial. Future trials should have improved designs, more sensitive outcome measures relevant to people with CIDP, and longer treatment durations.

Treatment of chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is one of the acquired demyelinating neuropathies and is considered to be immune mediated. Diagnosis is typically based on clinical history, neurologic examination, electrophysiologic studies, CSF studies, and pathologic examination. Early diagnosis and treatment is important to prevent irreversible axonal loss and optimize improvement in function. The first-line agents for treatment are intravenous immunoglobulin (IVIg), corticosteroids, and plasmapheresis, which have all been demonstrated to be effective in controlled studies. Studies have not shown a significant difference between these three treatments, and the initial choice of therapy is often based on availability, cost, ease of administration, and side effect profile. If patients do not respond to one of these agents, they may respond to one of the others and sometimes in combination. If the first-line agents are not effective, chemotherapeutic or immunosuppressive agents may be considered. There are limited controlled studies of these modalities, and they are often used in conjunction with a first-line treatment. The majority of patients require long-term therapy to maintain a response and to prevent relapse.

Novel immunotherapeutic strategies in chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a chronic immune-mediated neuropathy: it is clinically heterogeneous (relapsing-remitting form, chronic progressive form, monophasic form or CIDP having a Guillain-Barré syndrome-like onset), but potentially treatable. Although its pathophysiology remains largely unknown, CIDP is considered an immune-mediated neuropathy. Therefore, many immunotherapies have been proposed in this peripheral nervous system disorder, the most known efficient treatments being intravenous immunoglobulin, corticosteroids and plasma exchange. However, these therapies remain unsatisfactory for many patients, so numerous other immunotherapeutic strategies have been evaluated, based on their immunosuppressant or immunomodulatory potency. We have performed a large review of the literature about treatment in CIDP, with a special emphasis on novel and alternative immunotherapeutic strategies.

Immunotherapy in Peripheral Neuropathies

Immunotherapy has been investigated in a small subset of peripheral neuropathies, including an acute one, Guillain-Barré syndrome, and 3 chronic forms: chronic inflammatory demyelinating polyradiculoneuropathy, multifocal motor neuropathy, and neuropathy associated with IgM anti-myelin-associated glycoprotein. Several experimental studies and clinical data are strongly suggestive of an immune-mediated pathogenesis. Either cell-mediated mechanisms or antibody responses to Schwann cell, compact myelin, or nodal antigens are considered to act together in an aberrant immune response to cause damage to peripheral nerves. Immunomodulatory treatments used in these neuropathies aim to act at various steps of this pathogenic process. However, there are many phenotypic variants and, consequently, there is a significant difference in the response to immunotherapy between these neuropathies, as well as a need to improve our knowledge and long-term management of chronic forms.

Current and future immunotherapy targets in autoimmune neurology

Randomized controlled treatment trials of autoimmune neurologic disorders are generally lacking and data pertaining to treatment are mostly derived from expert opinion, large case series, and anecdotal reports. The treatment of autoimmune neurologic disorders comprises oncologic therapy (where appropriate) and immunotherapy. In this chapter, we first describe the standard acute and chronic immunotherapies and provide a practical overview of their use in the clinic (mechanisms of action, dosing, monitoring, and side effects). Novel approaches to treatment of autoimmune neurologic disorders, through new drug discovery or repurposing, are dependent on improved mechanistic understanding of immunopathology. Such approaches, with emphasis on monoclonal antibodies, are discussed using the paradigm of three autoimmune neurologic disorders whose immunopathogenesis is better understood, specifically myasthenia gravis, neuromyelitis optica, and chronic inflammatory demyelinating polyradiculoneuropathy. It is important to realize that the treatment strategy and management plan must be individualized for each patient. In general these are influenced by the following: clinical severity, antibody type, presence or absence of cancer, and prior treatment response, if known.

Future perspectives in target-specific immunotherapies of myasthenia gravis

Myasthenia gravis (MG) is an autoimmune disease caused by complement-fixing antibodies against acetylcholine receptors (AChR); antigen-specific CD4+ T cells, regulatory T cells (Tregs) and T helper (Th) 17+ cells are essential in antibody production. Target-specific therapeutic interventions should therefore be directed against antibodies, B cells, complement and molecules associated with T cell signaling. Even though the progress in the immunopathogenesis of the disease probably exceeds any other autoimmune disorder, MG is still treated with traditional drugs or procedures that exert a non-antigen specific immunosuppression or immunomodulation. Novel biological agents currently on the market, directed against the following molecular pathways, are relevant and specific therapeutic targets that can be tested in MG: (a) T cell intracellular signaling molecules, such as anti-CD52, anti-interleukin (IL) 2 receptors, anti- costimulatory molecules, and anti-Janus tyrosine kinases (JAK1, JAK3) that block the intracellular cascade associated with T-cell activation; (b) B cells and their trophic factors, directed against key B-cell molecules; (c) complement C3 or C5, intercepting the destructive effect of complement-fixing antibodies; (d) cytokines and cytokine receptors, such as those targeting IL-6 which promotes antibody production and IL-17, or the p40 subunit of IL-12/1L-23 that affect regulatory T cells; and (e) T and B cell transmigration molecules associated with lymphocyte egress from the lymphoid organs. All drugs against these molecular pathways require testing in controlled trials, although some have already been tried in small case series. Construction of recombinant AChR antibodies that block binding of the pathogenic antibodies, thereby eliminating complement and antibody-depended-cell-mediated cytotoxicity, are additional novel molecular tools that require exploration in experimental MG.

Is dosing of therapeutic immunoglobulins optimal? A review of a three-decade long debate in europe

The consumption of immunoglobulins (Ig) is increasing due to better recognition of antibody deficiencies, an aging population, and new indications. This review aims to examine the various dosing regimens and research developments in the established and in some of the relevant off-label indications in Europe. The background to the current regulatory settings in Europe is provided as a backdrop for the latest developments in primary and secondary immunodeficiencies and in immunomodulatory indications. In these heterogeneous areas, clinical trials encompassing different routes of administration, varying intervals, and infusion rates are paving the way toward more individualized therapy regimens. In primary antibody deficiencies, adjustments in dosing and intervals will depend on the clinical presentation, effective IgG trough levels and IgG metabolism. Ideally, individual pharmacokinetic profiles in conjunction with the clinical phenotype could lead to highly tailored treatment. In practice, incremental dosage increases are necessary to titrate the optimal dose for more severely ill patients. Higher intravenous doses in these patients also have beneficial immunomodulatory effects beyond mere IgG replacement. Better understanding of the pharmacokinetics of Ig therapy is leading to a move away from simplistic "per kg" dosing. Defective antibody production is common in many secondary immunodeficiencies irrespective of whether the causative factor was lymphoid malignancies (established indications), certain autoimmune disorders, immunosuppressive agents, or biologics. This antibody failure, as shown by test immunization, may be amenable to treatment with replacement Ig therapy. In certain immunomodulatory settings [e.g., idiopathic thrombocytopenic purpura (ITP)], selection of patients for Ig therapy may be enhanced by relevant biomarkers in order to exclude non-responders and thus obtain higher response rates. In this review, the developments in dosing of therapeutic immunoglobulins have been limited to high and some medium priority indications such as ITP, Kawasaki' disease, Guillain-Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy, myasthenia gravis, multifocal motor neuropathy, fetal alloimmune thrombocytopenia, fetal hemolytic anemia, and dermatological diseases.

Challenges in the treatment of chronic inflammatory demyelinating polyradiculoneuropathy

Chronic idiopathic demyelinating polyradiculoneuropathy (CIDP) is a rare disease, the most frequent one within the spectrum of the so-called "chronic immune-mediated neuropathies". Challenges in the treatment of CIDP firstly concern its diagnosis, which may be difficult, mainly for the atypical forms. Secondly, challenges encompass the choice of the first-line treatment, such as corticosteroids, intravenous immunoglobulins (IVIg), and plasma exchanges (PE) that have been proven as efficacious by several randomized controlled trials (RCT). Recent reports have focused on both different regimens of corticosteroids, and the occurrence of relapses following treatment with either corticosteroids or IVIg. These data may be helpful for the choice of the first-line treatment and may result in changing the guidelines for treatment of CIDP in clinical practice. The third and more difficult challenge is to manage long-term treatment for CIDP, since no immunomodulatory treatment has to date been proven as efficacious in this situation. Lastly, challenges in the treatment concern the choice of the best outcome measure for CIDP in RCT and clinical practice. The aim of this article is to overview the results of the more recently reported published trials for CIDP, and to give some insights for the current and future management of CIDP.

Successful treatment of refractory Guillain-Barré syndrome with alemtuzumab in a patient with chronic lymphocytic leukemia

This is the case of a 79-year-old man with chronic lymphocytic leukemia who presented with Guillain-Barré syndrome with features overlapping with the Miller Fisher syndrome and Bickerstaff brainstem encephalitis and positive antiganglioside GQ1b antibody about 6 months after treatment with bendamustine and rituximab. His clinical and neurologic condition continued to deteriorate despite sequential treatment with corticosteroids, intravenous immunoglobulin and plasmapheresis, but in the end, he had a complete and durable response to treatment with alemtuzumab.

Chronic inflammatory demyelinating polyradiculoneuropathy: update on clinical features, phenotypes and treatment options

PURPOSE OF REVIEW

In this review, we focus on less recognised signs and symptoms in typical chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and on the clinical presentation, course of disease and response to treatment of the atypical CIDP phenotypes.

RECENT FINDINGS

Frequently occurring and often disabling symptoms in CIDP such as fatigue, pain and tremor have recently been emphasised, whereas autonomic dysfunction, if present, is usually mild. Sensory CIDP is probably the most frequent atypical CIDP phenotype and diagnosis can be difficult in the absence of clear demyelinating features on nerve conduction studies. The most important study comparing intravenous immunoglobulin treatment with intravenous methylprednisolone showed a lower rate of discontinuation due to inefficacy, adverse events or intolerance with intravenous immunoglobulin treatment. However, improvement after corticosteroids seems to be more long-lasting than after intravenous immunoglobulin suggesting superior long-term immunosuppressive and immunomodulating effect of corticosteroids in CIDP.

SUMMARY

Symptoms other than the classical motor and sensory symptoms can lead to significant disability in CIDP patients. Based on limited evidence from largely small retrospective case series, we conclude that atypical CIDP phenotypes often have a different course of disease and sometimes response to treatment when compared with typical CIDP. Prospective multicentre cohort studies using standardised clinical description, electrophysiological parameters and outcome measures are needed to study the natural disease course of these phenotypes including response to different treatments.

Disease-modifying therapy in multiple sclerosis and chronic inflammatory demyelinating polyradiculoneuropathy: common and divergent current and future strategies

Multiple sclerosis (MS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) represent chronic, autoimmune demyelinating disorders of the central and peripheral nervous system. Although both disorders share some fundamental pathogenic elements, treatments do not provide uniform effects across both disorders. We aim at providing an overview of current and future disease-modifying strategies in these disorders to demonstrate communalities and distinctions. Intravenous immunoglobulins (IVIG) have demonstrated short- and long-term beneficial effects in CIDP but are not effective in MS. Dimethyl fumarate (BG-12), teriflunomide and laquinimod are orally administered immunomodulatory drugs that are already approved or likely to be approved in the near future for the basic therapy of patients with relapsing-remitting MS (RRMS) due to positive results in Phase III clinical trials. However, clinical trials with these drugs in CIDP have not (yet) been initiated. Natalizumab and fingolimod are approved for the treatment of RRMS, and trials to evaluate their safety and efficacy in CIDP are now planned. Alemtuzumab, ocrelizumab and daclizumab respresent monoclonal antibodies in advanced stages of clinical development for their use in RRMS patients. Attempts to study the safety and efficacy of alemtuzumab and B cell-depleting anti-CD20 antibodies, i.e. rituximab, ocrelizumab or ofatumumab, in CIDP patients are currently under way. We provide an overview of the mechanism of action and clinical data available on disease-modifying immunotherapy options for MS and CIDP. Enhanced understanding of the relative effects of therapies in these two disorders may aid rational treatment selection and the development of innovative treatment approaches in the future.

Treatment of chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a sporadically occurring, acquired neuropathic condition of autoimmune origin with chronic progressive or relapsing-remitting disease course. CIDP is a treatable disorder; a variety of immunosuppressive and immunomodulatory agents are available to modify, impede, and even reverse the neurological deficits and sequelae that manifest in the course of the disease. However, in many cases CIDP is not curable. Challenges that remain in the treatment of CIDP patients are well recognized and include a remarkably individual heterogeneity in terms of disease course and treatment response as well as a lack of objective and feasible measures to predict and monitor the responsiveness to the available therapies. In this chapter an overview of the currently used drugs in the treatment of CIDP patients is given and some important and controversial issues that arise in the context of care for CIDP patients are discussed.

Multifocal motor neuropathy: current therapies and novel strategies

Multifocal motor neuropathy (MMN) is a purely motor mononeuritis multiplex characterized by the presence of conduction block on motor but not on sensory nerves and by the presence of high titers of anti-GM1 antibodies. Several data point to a pathogenetic role of the immune system in this neuropathy, although this has not yet been proved. Several uncontrolled studies and randomized controlled trials have demonstrated the efficacy of therapy with high-dose intravenous immunoglobulin (IVIg) in MMN. However, this therapy has a short-lasting effect that needs to be maintained with periodic infusions. This can be partly overcome by the use of subcutaneous immunoglobulin (SCIg) at the same dose. The high cost and need for repeated infusions have led to the search for other immune therapies, the efficacy of which have not yet been confirmed in randomized trials. In addition, some therapies, including corticosteroids and plasma exchange, are not only ineffective but have been associated with clinical worsening. More recently, a number of novel therapies have been investigated in MMN, including interferon-β1a, the anti-CD20 monoclonal antibody rituximab and the complement inhibitor eculizumab. Preliminary data from open-label uncontrolled studies show that some patients improve after these therapies; however, randomized controlled trials are needed to confirm efficacy. Until then, IVIg (and SCIg) remains the mainstay of treatment in MMN, and the use of other immune therapies should only be considered for patients not responding to, or becoming resistant to, IVIg.

Childhood chronic inflammatory demyelinating polyneuropathy: an overview of 10 cases in the modern era

Chronic inflammatory demyelinating polyneuropathy is a rare condition in children. In this article, we report our experience in the management of 10 cases of childhood chronic inflammatory demyelinating polyneuropathy in a single center, in the era of contrast-enhanced magnetic resonance imaging (MRI), genetic microarray, and chronic inflammatory demyelinating polyneuropathy disease activity status. Robust neurophysiologic abnormalities were present in all cases and both MRI and lumbar puncture were useful adjuncts in diagnosis. Genetic microarray is a simple technique useful in excluding the most common hereditary demyelinating neuropathy. Intravenous immunoglobulin was an effective first-line therapy in most cases, with refractory cases responding to corticosteroids and rituximab. We found the chronic inflammatory demyelinating polyneuropathy disease activity status useful for assessing outcome at final follow-up, whereas the modified Rankin score was better for assessing peak motor disability.

Alemtuzumab

Alemtuzumab (Campath®, MabCampath®, Genzyme) is an IgG1k anti-CD52 humanized monoclonal antibody (mAb) that was first licensed in March 2001 by FDA. EMEA granted its approval in July 2001 and Health Canada in November 2005. The initial indication was limited to B-CLL previously treated and resistant to alkylating agents. Starting from 2007, alemtuzumab was approved also as first-line therapy of B-CLL. So far, it has been experienced in over 60 countries.

Immunomodulatory treatment other than corticosteroids, immunoglobulin and plasma exchange for chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a disease causing progressive or relapsing and remitting weakness and numbness. It is probably due to an autoimmune process. Immunosuppressive or immunomodulatory drugs would be expected to be beneficial. This review was first published in 2003 and has been most recently updated in 2013.

OBJECTIVES

We aimed to review systematically the evidence from randomised trials of immunomodulatory and immunosuppressive agents other than corticosteroids, immunoglobulin and plasma exchange for CIDP.

SEARCH METHODS

On 9 July 2012, we searched the Cochrane Neuromuscular Disease Group Specialized Register (July 2012), CENTRAL (2012, Issue 6 in The Cochrane Library), MEDLINE (January 1977 to July 2012), EMBASE (January 1980 to July 2012), CINAHL (January 1982 to July 2012) and LILACS (January 1982 to July 2012). We contacted the authors of the trials identified and other disease experts seeking other published and unpublished trials.

SELECTION CRITERIA

We sought randomised and quasi-randomised trials of all immunosuppressive agents such as azathioprine, cyclophosphamide, methotrexate, ciclosporin, mycophenolate mofetil, and rituximab and all immunomodulatory agents such as interferon alfa and interferon beta, in participants fulfilling standard diagnostic criteria for CIDP.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials, judged their risk of bias and extracted data. We wanted to measure the change in disability after one year as our primary outcome. Our secondary outcomes were change in disability after four or more weeks (from randomisation), change in impairment after at least one year, change in maximum motor nerve conduction velocity and compound muscle action potential amplitude after one year and for those participants who were receiving corticosteroids or intravenous immunoglobulin, the amount of this medication given during at least one year after randomisation. Participants with one or more serious adverse events during the first year was also a secondary outcome.

MAIN RESULTS

Four trials fulfilled the selection criteria, one of azathioprine (27 participants), two of interferon beta-1a (77 participants in total) and one of methotrexate (60 participants). The risk of bias in the two trials of interferon beta-1a for CIDP and the trial of methotrexate was assessed to be low but bias in the trial of azathioprine was judged high. None of these trials showed significant benefit in the primary outcome (measured only in the methotrexate study) or secondary outcomes selected for this review. Severe adverse events occurred no more frequently than in the placebo groups for methotrexate and interferon beta-1a, but participant numbers were low. There was no adverse event reporting in the azathioprine study.

AUTHORS' CONCLUSIONS

The evidence from randomised trials does not show significant benefit from azathioprine, interferon beta-1a or methotrexate but none of the trials was large enough to rule out small or moderate benefit. The evidence from observational studies is insufficient to avoid the need for randomised controlled trials to discover whether these drugs are beneficial. Future trials should have improved designs, more sensitive outcome measures and longer durations.

Chronic inflammatory demyelinating polyneuropathy

OPINION STATEMENT

Chronic Inflammatory polyneuropathies are an important group of neuromuscular disorders that present chronically and progress over more than 8 weeks, being referred to as chronic inflammatory demyelinating polyneuropathy (CIDP). Despite tremendous progress in elucidating disease pathogenesis, the exact triggering event remains unknown. Our knowledge regarding diagnosis and management of CIDP and its variants continues to expand, resulting in improved opportunities for identification and treatment. Most clinical neurologists will be involved in the management of patients with these disorders, and should be familiar with available therapies for CIDP. We review the distinctive clinical, laboratory, and electro-diagnostic features that aid in diagnosis. We emphasize the importance of clinical patterns that define treatment responsiveness and the most appropriate therapies in order to improve prognosis.

Novel future therapeutic options in myasthenia gravis

BACKGROUND

Myasthenia Gravis (MG) is an autoimmune disease caused by complement-fixing antibodies against the acetylcholine receptors (AChR). Antigen-specific CD4+ T cells, Tregs and Th17+ are also necessary. Consequently, antibodies, B cells, molecules associated with signalling pathways on T helper cells, cytokines and complement are targets for more specific treatment options.

OBJECTIVES

Because available immunosuppressive therapies cause unacceptable side effects after long-term use or are not always effective in inducing remission, novel biological agents directed against the following targets might be options for future therapies in MG: 1) T cell Intracellular Signaling Pathways associated with T cell activation, such as monoclonal antibodies against CD52, Interleukin 2-receptor (IL-2 R), co-stimulatory molecules or compounds inhibiting Janus tyrosine kinases JAK1, JAK3; 2) B cells, against key B cell-surface molecules or trophic factors B cell activation factor (BAFF) and a proliferating inducing ligand (APRIL); 3) Complement, against C3 or C5 that intercept membranolytic attack complex formation; 4) Cytokines and cytokine receptors, including IL-6, IL-17, the p40 subunit of IL12/1L-23, and GM-CSF; and 5) Lymphocyte migration molecules. Construction of recombinant AChR antibodies that block the binding of the pathogenic antibodies, can be a future molecular tool.

CONCLUSION

New biological agents are in the offing for future therapies in MG. Their efficacy needs to be secured with vigorously controlled clinical trials and weighted against excessive cost and rare complications.

Monoclonal antibodies in neuroinflammatory diseases

INTRODUCTION

Monoclonal antibodies (mAbs) represent an emerging and rapidly growing field of therapy in neuroinflammatory diseases. Adhesion molecule blockade by natalizumab represents the first approved mAb therapy in neurology, approved for therapy of highly active multiple sclerosis (MS). Removal of immune cells by anti-CD52 mAb alemtuzumab or anti-CD20 mAb rituximab are other prime examples with existing positive Phase II and Phase III trials. MS clearly represents the neuroinflammatory disease entity with the largest body of evidence. However, some of these approaches are currently investigated or translated for use in other, rare neuroinflammatory diseases, such as neuromyelitis optica (NMO), inflammatory neuropathies and (neuro)-muscular disorders.

AREAS COVERED

This review will highlight the most relevant therapeutic approaches involving mAbs in the field of neuroinflammatory diseases as published in peer-reviewed journals and presented on international meetings.

EXPERT OPINION

There is continuously growing evidence on the therapeutic relevance of mAbs in neuroinflammatory disorders. In MS meanwhile several studies have provided evidence for efficacy: In addition to natalizumab, approved in 2006, several other candidates are under development, the most eminent examples with the most advanced study programs being anti-CD52 alemtuzumab, anti-CD20 principles and anti-CD25 daclizumab. Other intriguing candidates are anti-IL-17 strategies, and interference with the complement pathway, partly also developed for other neuroinflammatory disorders.

Alemtuzumab: evidence for its potential in relapsing-remitting multiple sclerosis

Alemtuzumab (previously known as Campath^®) is a humanized monoclonal antibody directed against the CD52 antigen on mature lymphocytes that results in lymphopenia and subsequent modification of the immune repertoire. Here we explore evidence for its efficacy and safety in relapsing–remitting multiple sclerosis. One Phase II and two Phase III trials of alemtuzumab versus active comparator (interferon beta-1a) have been reported. Two of these rater-blinded randomized studies assessed clinical and radiological outcomes in treatment-naïve patients; one explored patients who had relapsed despite first-line therapy. Compared to interferon beta-1a, alemtuzumab reduced the relapse rate by 49%–74% (P < 0.0001), and in two studies it reduced the risk of sustained disability accumulation by 42%–71% (P < 0.01). In one study (Comparison of Alemtuzumab and Rebif Efficacy in Multiple Sclerosis; CARE-MS1), there was no significant difference compared to interferon, perhaps reflecting the surprisingly low frequency of disability events in the comparator group. After alemtuzumab, the Expanded Disability Status Scale score improved by 0.14–1.2 points, culminating in a net advantage with alemtuzumab of 0.41–0.77 points over interferon in the CAMMS223 and CARE-MS2 trials (both P < 0.001). Radiological markers of new lesion formation and brain atrophy following alemtuzumab were significantly improved when compared to interferon in all studies. Adverse events were more common following alemtuzumab than interferon beta-1a (7.2–8.66 versus 4.9–5.7 events per person-year). While infusion reactions are the most common, autoimmunity is the most concerning; within Phase III studies, thyroid disorders (17%–18% versus 5%–6%) and immune thrombocytopenic purpura (1% versus 0%) were reported in patients taking alemtuzumab and interferon beta-1a, respectively. All patients responded to conventional therapy. One patient taking alemtuzumab in the Phase II study suffered a fatal intracranial hemorrhage following immune thrombocytopenic purpura, heralding assiduous monitoring of all patients thereafter. Alemtuzumab has been submitted for licensing in relapsing–remitting multiple sclerosis in the United States and Europe.

A review of the use of biological agents for chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a group of idiopathic, acquired, immune-mediated inflammatory demyelinating diseases of the peripheral nervous system. A majority of patients with CIDP respond to "first-line" treatment with IVIG, plasmapheresis and/or corticosteroids. There exists insufficient evidence to ascertain the benefit of treatment with "conventional" immunosuppressive drugs. The inconsistent efficacy, long-term financial burden and health risks of non-specific immune altering therapy have drawn recurrent attention to the possible usefulness of a variety of biological agents that target key aspects in the CIDP immunopathogenic pathways. This review aims to give an updated account of the scientific rationale and potential use of biological therapeutics in patients with CIDP. No specific treatment recommendations are given. The discovery, development and application of biological markers by modern molecular diagnostic techniques may help identify drug-naïve or treatment-resistant CIDP patients most likely to respond to targeted immunotherapy.

An update on the management of chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an immune mediated disorder of the peripheral nervous system with clinical features that include weakness, sensory loss, imbalance, pain and impaired ambulation which may lead to substantial disability. This review highlights current treatment strategies for CIDP, how best to utilize proven therapies such as intravenous immunoglobulin, oral prednisone, pulse dexamethasone, and plasma exchange, and when and how to use alternative immunosuppressive agents when first-line therapies are ineffective or poorly tolerated.

Chronic inflammatory demyelinating polyradiculoneuropathy: from bench to bedside

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is the most common treatable chronic autoimmune neuropathy. Multiple diagnostic criteria have been established, with the primary goal of identifying neurophysiologic hallmarks of acquired demyelination. Treatment modalities have expanded to include numerous immunomodulatory therapies, although the best evidence continues to be for corticosteroids, plasma exchange, and intravenous immunoglobulin (IVIg). This review describes the pathology, epidemiology, pathogenesis, diagnosis, and treatment of CIDP.

Childhood chronic inflammatory demyelinating polyneuroradiculopathy--three cases and a review of the literature

BACKGROUND

Chronic inflammatory demyelinating polyneuroradiculopathy (CIDP) is an autoimmune disease of the peripheral nervous system, causing demyelination and even axonal degeneration. In children, abnormal gait as a first sign of muscle weakness is a frequent reason to seek medical attention. Diagnosis is made on the basis of clinical characteristics, electromyography and nerve conduction studies, and elevated protein in cerebrospinal fluid.

AIMS

We present three new cases of CIDP. The literature was reviewed in order to obtain more information on presentation, outcome and treatment strategies world-wide.

RESULTS

The course of disease can be relapsing-remitting or chronic-progressive. From case series it is known that first-line immunotherapy (intravenously administered immunoglobulin, corticosteroids or plasmapheresis) is initially of benefit in most children with CIDP. There is little evidence, however, on second-line therapies as azathioprine, cyclosporine A, mycophenolate mofetil, methothrexate, cyclophosphamide and IFN alpha. Although the outcome of children with CIDP is generally regarded to be good, disease related disability can be severe.

CONCLUSION

Childhood CIDP is rare. In general and in comparison to adults, children tend to have a more acute progressive onset, with more severe symptoms. Showing a higher tendency towards a relapsing-remitting course, children often show a better and faster improvement after therapy, and a more favorable outcome. Swift recognition of CIDP and empiric start of treatment are considered important to avoid potentially irreversible axonal damage and associated disability. Response to first-line therapies is usually favorable, however recommendations regarding the choice of second-line therapy can only be made on the basis of current practice described in case reports. Safety and efficacy data are insufficient. The cases described show that trial and error are often involved in finding an optimal treatment strategy, especially in those patients refractory to first-line treatment or with a prolonged course. Clinical experience with immunomodulatory treatment is paramount when treating children with CIDP.

Advances in the diagnosis, pathogenesis and treatment of CIDP

Chronic inflammatory demyelinating polyneuropathy (CIDP) is the most common chronic autoimmune neuropathy. Despite clinical challenges in diagnosis-owing in part to the existence of disease variants, and different views on how many electrophysiological abnormalities are needed to document demyelination-consensus criteria seem to have been reached for research or clinical practice. Current standard of care involves corticosteroids, intravenous immunoglobulin (IVIg) and/or plasmapheresis, which provide short-term benefits. Maintenance therapy with IVIg can induce sustained remission, increase quality of life and prevent further axonal loss, but caution is needed to avoid overtreatment. Commonly used immunosuppressive drugs offer minimal benefit, necessitating the development of new therapies for treatment-refractory patients. Advances in our understanding of the underlying immunopathology in CIDP have identified new targets for future therapeutic efforts, including T cells, B cells, and transmigration and transduction molecules. New biomarkers and scoring systems represent emerging tools with the potential to predict therapeutic responses and identify patients with active disease for enrollment into clinical trials. This Review highlights the recent advances in diagnosing CIDP, provides an update on the immunopathology including new target antigens, and discusses current treatments, ongoing challenges and future therapeutic directions.