Treatment of chronic inflammatory demyelinating polyneuropathy with high dose intravenous methylprednisolone monthly for five years: 10-Year follow up

Chronic Inflammatory Demyelinating Polyradiculoneuropathy: Current Therapeutic Approaches and Future Outlooks

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a treatable autoimmune disorder, for which different treatment options are available. Current first-line evidence-based therapies for CIDP include intravenous and subcutaneous immunoglobulins, corticosteroids and plasma exchanges. Despite lack of evidence, cyclophosphamide, rituximab and mycophenolate mofetil are commonly used in circumstances of refractoriness and, more debatably, of perceived overdependence on first-line therapies. Rituximab is currently the object of a randomized controlled trial for CIDP. Based on case series, and although rarely considered, haematopoietic autologous stem cell transplants may be effective in refractory disease, with low mortality and high remission rates. A new therapeutic option has appeared with efgartigimod, a neonatal Fc receptor blocker, recently shown to significantly lower relapse rate versus placebo, after withdrawal from previous immunotherapy. Other neonatal Fc receptor blockers, nipocalimab and batoclimab, are under study. The C1 complement-inhibitor SAR445088, acting in the proximal portion of the classical complement system, is currently the subject of a new study in treatment-responsive, refractory and treatment-naïve subjects. Finally, Bruton Tyrosine Kinase inhibitors, which exert anti-B cell effects, may represent another future research avenue. The widening of the therapeutic armamentarium enhances the need for improved evaluation of treatment effects and reliable biomarkers in CIDP.

Pharmacokinetic Study of Intranasal Dexamethasone and Methylprednisolone Compared with Intravenous Administration: Two Open-Label, Single-Dose, Two-Period, Two-Sequence, Cross-Over Study in Healthy Volunteers

Dexamethasone (DXM) and methylprednisolone (MEP) are potent glucocorticoids used to control several inflammatory conditions. Evidence of delayed DXM reaching the central nervous system (CNS) as well as tachyphylaxis and systemic, undesirable side effects are the main limitations of peripheral delivery. Intranasal administration offers direct access to the brain as it bypasses the blood-brain barrier. The Mucosal Atomization Device is an optimal tool that can achieve rapid absorption into the CNS and the bloodstream across mucosal membranes. This study was designed to evaluate and compare the bioavailability of DXM and MEP after intranasal versus intravenous administration. Two open-label, balanced, randomized, two-treatment, two-period, two-sequence, single-dose, crossover studies were conducted, which involved healthy male and female adult volunteers. After intranasal administration, DXM and MEP were detected in plasma after the first sampling time. Mean peak concentrations of DXM and MEP were 86.61 ng/mL at 60 min and 843.2 ng/mL at 1.5 h post-administration, respectively. DXM and MEP showed high absolute bioavailability, with values of 80% and 95%, respectively. No adverse effects were observed. DXM and MEP systemic bioavailability by intranasal administration was comparable with the intravenous one, suggesting that the intranasal route can be used as a non-invasive and appropriate alternative for systemic drug delivery.

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

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

History, Diagnosis, and Management of Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is probably the best recognized progressive immune-mediated peripheral neuropathy. It is characterized by a symmetrical, motor-predominant peripheral neuropathy that produces both distal and proximal weakness. Large-fiber abnormalities (weakness and ataxia) predominate, whereas small-fiber abnormalities (autonomic and pain) are less common. The pathophysiology of CIDP is inflammatory demyelination that manifests as slowed conduction velocities, temporal dispersion, and conduction block on nerve conduction studies and as segmental demyelination, onion-bulb formation, and endoneurial inflammatory infiltrates on nerve biopsies. Although spinal fluid protein levels are generally elevated, this finding is not specific for the diagnosis of ClDP. Other neuropathies can resemble CIDP, and it is important to identify these to ensure correct treatment of these various conditions. Consequently, metastatic bone surveys (for osteosclerotic myeloma), serum electrophoresis with immunofixation (for monoclonal gammopathies), and human immunodeficiency virus testing should be considered for testing in patients with suspected CIDP. Chronic inflammatory demyelinating polyradiculoneuropathy can present as various subtypes, the most common being the classical symmetrical polyradiculoneuropathy and the next most common being a localized asymmetrical form, multifocal CIDP. There are 3 well-established, first-line treatments of CIDP-corticosteroids, plasma exchange, and intravenous immunoglobulin-with most experts using intravenous immunoglobulin as first-line therapy. Newer immune-modulating drugs can be used in refractory cases. Treatment response in CIDP should be judged by objective measures (improvement in the neurological or electrophysiological examination), and treatment needs to be individualized to each patient.

Corticosteroids for chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a progressive or relapsing and remitting paralysing illness, probably due to an autoimmune response, which should benefit from corticosteroid treatment. Non-randomised studies suggest that corticosteroids are beneficial. Two commonly used corticosteroids are prednisone and prednisolone. Both are usually given as oral tablets. Prednisone is converted into prednisolone in the liver so that the effect of the two drugs is usually the same. Another corticosteroid, dexamethasone, is more potent and is used in smaller doses. The review was first published in 2001 and last updated in 2015; we undertook this update to identify any new evidence.

OBJECTIVES

To assess the effects of corticosteroid treatment for CIDP compared to placebo or no treatment, and to compare the effects of different corticosteroid regimens.

SEARCH METHODS

On 8 November 2016, we searched the Cochrane Neuromuscular Specialised Register, Cochrane Central Register of Controlled Trials, MEDLINE, and Embase for randomised trials of corticosteroids for CIDP. We searched clinical trials registries for ongoing trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-RCTs of treatment with any corticosteroid or adrenocorticotrophic hormone for CIDP, diagnosed by an internationally accepted definition.

DATA COLLECTION AND ANALYSIS

Two authors extracted data from included studies and assessed the risk of bias independently. The intended primary outcome was change in disability, with change in impairment after 12 weeks and side effects as secondary outcomes. We assessed strength of evidence using the GRADE approach.

MAIN RESULTS

One non-blinded RCT comparing prednisone with no treatment in 35 eligible participants did not measure the primary outcome for this systematic review. The trial had a high risk of bias. Neuropathy Impairment Scale scores after 12 weeks improved in 12 of 19 participants randomised to prednisone, compared with five of 16 participants randomised to no treatment (risk ratio (RR) for improvement 2.02 (95% confidence interval (CI) 0.90 to 4.52; very low-quality evidence). The trial did not report side effects in detail, but one prednisone-treated participant died.A double-blind RCT comparing daily standard-dose oral prednisolone with monthly high-dose oral dexamethasone in 40 participants reported none of the prespecified outcomes for this review. The trial had a low risk of bias, but the quality of evidence was limited as it came from a single small study. There was little or no difference in number of participants who achieved remission (RR 1.11; 95% CI 0.50 to 2.45 in favour of monthly dexamethasone; moderate-quality evidence), or change in disability or impairment after one year (low-quality evidence). Change of grip strength or Medical Research Council (MRC) scores demonstrated little or no difference between groups (moderate-quality to low-quality evidence). Eight of 16 people in the prednisolone group and seven of 24 people in the dexamethasone group deteriorated. Side effects were similar with each regimen, except that sleeplessness was less common with monthly dexamethasone (low-quality evidence) as was moon facies (moon-shaped appearance of the face) (moderate-quality evidence).Experience from large non-randomised studies suggests that corticosteroids are beneficial, but long-term use causes serious side effects.

AUTHORS' CONCLUSIONS

We are very uncertain about the effects of oral prednisone compared with no treatment, because the quality of evidence from the only RCT that exists is very low. Nevertheless, corticosteroids are commonly used in practice, supported by very low-quality evidence from observational studies. We also know from observational studies that corticosteroids carry the long-term risk of serious side effects. The efficacy of high-dose monthly oral dexamethasone is probably little different from that of daily standard-dose oral prednisolone. Most side effects occurred with similar frequencies in both groups, but with high-dose monthly oral dexamethasone moon facies is probably less common and sleeplessness may be less common than with oral prednisolone. We need further research to identify factors that predict response.

Steroids for chronic inflammatory demyelinating polyradiculoneuropathy: evidence base and clinical practice

Evidence-based therapies for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) consist of corticosteroids, intravenous immunglobulins (IVIg), and plasma exchange. Steroids represent the oldest treatment used historically. In countries where readily available and affordable, IVIg tends to be favored as first-line treatment. The reason for this preference, despite substantially higher costs, is the perception that IVIg is more efficacious and safer than corticosteroids. However, the unselected use of IVIg as a first-line treatment option in all cases of CIDP raises issues of cost-effectiveness in the long-term. Furthermore, serious although rare, particularly thromboembolic side effects may result from their use. Recent data from randomized trials suggest pulsed corticosteroids to have a higher potential in achieving therapy-free remission or longer remission-free periods compared with IVIg, as well as relatively low rates of serious side effects when given as pulsed intravenous infusions during short periods of time. These specific advantages suggest that pulsed steroids could in many cases be used, as the first, rather than second choice of treatment when initiating immunomodulation in CIDP, primarily in hopes of achieving a remission after the short-term use. This article reviews the evidence base for the use of corticosteroids in its various forms in CIDP and factors that may influence clinicians' choice between IVIg and pulsed steroid treatment. The issue of efficacy, relapse rate and time, and side effect profile are analyzed, and some aspects from the authors' experience are discussed in relation to the possibility of using the steroid option as first-line therapy in a large proportion of patients with CIDP.

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.

Office immunotherapy in chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy

Intravenous immunoglobulin [IVIg], plasma exchange [PE], and corticosteroids are efficacious treatment in chronic inflammatory demyelinating polyneuropathy [CIDP]. IVIg is effective in multifocal motor neuropathy [MMN]. NIS, NIS-weakness, sum scores of raw amplitudes of motor fiber (CMAPs) amplitudes, and Dyck/Rankin score provided reliable measures to detect and scale abnormality and reflect change; they are therefore ideal for office management of response-based immunotherapy (R-IRx) of CIDP. Using efficacious R-IRx, a large early and late therapeutic response (≥ one-fourth were in remission or had recovered) was demonstrated in CIDP. In MMN only an early improvement with late non-significant worsening was observed. The difference in immunotherapy response supports a fundamental difference between CIDP (immune attack on Schwann cells and myelin) and MMN (attack on nodes of Ranvier and axons).

Corticosteroids for chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a progressive or relapsing and remitting paralysing illness probably due to an autoimmune response which should benefit from corticosteroids. Non-randomised studies suggest that corticosteroids are beneficial. Two commonly used corticosteroids are prednisone and prednisolone. Both are usually given as oral tablets. Prednisone is converted into prednisolone in the liver so that the effect of the two drugs is usually the same. Another corticosteroid, called dexamethasone, is more potent and is used in smaller doses.

OBJECTIVES

To assess the effects of corticosteroid treatment compared to placebo or no treatment for CIDP and to compare the effects of different corticosteroid regimes.

SEARCH METHODS

On 27 October 2014 we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE, and EMBASE for randomised trials of corticosteroids for CIDP. We searched three other databases for information to include in the Discussion, and clinical trials registries for ongoing trials.

SELECTION CRITERIA

We included randomised or quasi-randomised trials of treatment with any form of corticosteroids or adrenocorticotrophic hormone for CIDP, diagnosed by an internationally accepted definition.

DATA COLLECTION AND ANALYSIS

Two authors extracted the data and assessed risk of bias independently. The primary outcome was intended to be change in disability, with change in impairment after 12 weeks as a secondary outcome, and adverse events.

MAIN RESULTS

In one non-blinded randomised controlled trial (RCT) with 35 eligible participants, the primary outcome for this review was not available. The trial had a high risk of bias. Twelve of 19 participants treated with prednisone, compared with five of 16 participants randomised to no treatment, had improved neuropathy impairment scores after 12 weeks; the risk ratio (RR) for improvement was 2.02 (95% confidence interval (CI) 0.90 to 4.52). Adverse events were not reported in detail, but one prednisone-treated participant died.In a double-blind RCT comparing daily standard-dose oral prednisolone with monthly high-dose oral dexamethasone in 40 participants, none of the outcomes for this review were available. The trial had a low risk of bias. There were no significant differences in remission (RR 1.11; 95% CI 0.50 to 2.45 in favour of monthly dexamethasone) or change in disability or impairment after one year. Eight of 16 in the prednisolone, and seven of 24 in the dexamethasone group deteriorated. Adverse events were similar with each regimen, except that sleeplessness and moon facies (moon-shaped appearance of the face) were significantly less common with monthly dexamethasone.Experience from large non-randomised studies suggests that corticosteroids are beneficial, but long-term use causes serious side effects.

AUTHORS' CONCLUSIONS

Very low quality evidence from one small, randomised trial did not show a statistically significant benefit from oral prednisone compared with no treatment. Nevertheless, corticosteroids are commonly used in practice. According to moderate quality evidence from one RCT, the efficacy of high-dose monthly oral dexamethasone was not statistically different from that of daily standard-dose oral prednisolone. Most adverse events occurred with similar frequencies in both groups, but sleeplessness and moon facies were significantly less common with monthly dexamethasone. Further research is needed to identify factors which predict response.