IqYmune® is an effective maintenance treatment for multifocal motor neuropathy: A randomised, double-blind, multi-center cross-over non-inferiority study vs Kiovig®-The LIME Study

Therapeutic potentials of adoptive cell therapy in immune-mediated neuropathy

Immune-mediated neuropathy (IMN) is a group of heterogenous neuropathies caused by intricate autoimmune responses. For now, known mechanisms of different IMN subtypes involve the production of autoantibodies, complement activation, enhanced inflammation and subsequent axonal/demyelinating nerve damages. Recent therapeutic studies mainly focus on specific antibodies and small molecule inhibitors previously approved in rheumatoid diseases. Initial strategies based on the pathophysiologic features of IMN should be explored. Adoptive cell therapy (ACT) refers to the emerging immunotherapies in which circulating immunocytes are collected from peripheral blood and modified with killing and immunomodulatory capacities. It consists of chimeric antigen receptor-T cell therapy, T cell receptor-engineered T cell, CAR-Natural killer cell therapy, and others. In the last decade, ACT has demonstrated extraordinary potentials in treating cancers, infectious diseases and autoimmune diseases. Versatile combinations of targets, chimeric domains and effector cells greatly empower ACT to treat complicated immune disorders. In this review, we summarized the advances of ACT and envisioned suitable strategies for different IMN subtypes.

Dose-exposure-efficacy response of intravenous immunoglobulin G 10% in multifocal motor neuropathy

OBJECTIVE

Multifocal motor neuropathy is a rare chronic immune-mediated neuropathy with impaired grip strength representing a common symptom. While intravenous immunoglobulin G is an effective treatment for the disease, significant variation in treatment response has been observed but not well understood. This analysis characterized dose-exposure-response relationships in multifocal motor neuropathy, using grip strength as a clinical efficacy measure.

METHODS

Serum immunoglobulin G trough concentrations and grip strength data for the more affected hand from a Phase 3, randomized, double-blind, placebo-controlled, crossover trial of intravenous immunoglobulin 10% in 44 patients with multifocal motor neuropathy (NCT00666263) were used to develop a population pharmacokinetic-pharmacodynamic model.

RESULTS

The model adequately described the observed pharmacokinetic and pharmacodynamic data and relationships between intravenous immunoglobulin 10% dose, serum immunoglobulin G trough levels, grip strength, and inter-patient variabilities in multifocal motor neuropathy. Model-based simulations for various dosing regimens (0.4-2.0 g/kg every 2-4 weeks) indicated that ≥1.6 g/kg/month would achieve clinically meaningful improvements in grip strength (≥4 kg) in ≥70% of patients. More frequent dosing at an equivalent monthly dose led to a more consistent response in grip strength. Furthermore, splitting the dose over multiple days for high doses (>1 g/kg) did not impact grip strength.

INTERPRETATION

These findings suggest that the majority of patients with multifocal motor neuropathy would respond rapidly to intravenous immunoglobulin 10% with a range of dosing regimens. Shorter dosing intervals may avoid the diminishing response seen with longer dosing intervals. Dose-splitting provided similar outcomes while offering flexibility and convenience.

Updated consensus statement: Intravenous immunoglobulin in the treatment of neuromuscular disorders report of the AANEM ad hoc committee

Intravenous immune globulin (IVIG) is an immune-modulating biologic therapy that is increasingly being used in neuromuscular disorders despite the paucity of high-quality evidence for various specific diseases. To address this, the AANEM created the 2009 consensus statement to provide guidance on the use of IVIG in neuromuscular disorders. Since then, there have been several randomized controlled trials for IVIG, a new FDA-approved indication for dermatomyositis and a revised classification system for myositis, prompting the AANEM to convene an ad hoc panel to update the existing guidelines.New recommendations based on an updated systemic review of the literature were categorized as Class I-IV. Based on Class I evidence, IVIG is recommended in the treatment of chronic inflammatory demyelinating polyneuropathy, Guillain-Barré Syndrome (GBS) in adults, multifocal motor neuropathy, dermatomyositis, stiff-person syndrome and myasthenia gravis exacerbations but not stable disease. Based on Class II evidence, IVIG is also recommended for Lambert-Eaton myasthenic syndrome and pediatric GBS. In contrast, based on Class I evidence, IVIG is not recommended for inclusion body myositis, post-polio syndrome, IgM paraproteinemic neuropathy and small fiber neuropathy that is idiopathic or associated with tri-sulfated heparin disaccharide or fibroblast growth factor receptor-3 autoantibodies. Although only Class IV evidence exists for IVIG use in necrotizing autoimmune myopathy, it should be considered for anti-hydroxy-3-methyl-glutaryl-coenzyme A reductase myositis given the risk of long-term disability. Insufficient evidence exists for the use of IVIG in Miller-Fisher syndrome, IgG and IgA paraproteinemic neuropathy, autonomic neuropathy, chronic autoimmune neuropathy, polymyositis, idiopathic brachial plexopathy and diabetic lumbosacral radiculoplexopathy.

Incidence and risk factors for intravenous immunoglobulin-related hemolysis: A systematic review of clinical trial and real-world populations

Background

Severe hemolysis rarely occurs in patients receiving intravenous immunoglobulin (IVIG) therapy. A systematic review was performed to assess the incidence of IVIG‐related hemolysis and the impact of patient and product risk factors.

Study Design and Methods

A systematic literature search for terms related to “IVIG products”, “hemolysis,” and “adverse events” was conducted in Embase for articles published between January 1, 2015, and May 31, 2021. Studies with no clinical datasets, no IVIG treatment, or where IVIG was used to treat hemolytic conditions were excluded. Of the 430 articles retrieved, 383 were excluded based on titles/abstracts and 14 were excluded after in‐depth review.

Results

In total, 33 articles were analyzed and separated into observational studies (n = 16), clinical trials (n = 8), and case reports (n = 9). The incidence proportion for IVIG‐related hemolysis ranged from 0% to 19% in observational studies and 0%–21% in clinical trials. A higher incidence of IVIG‐related hemolysis was consistently reported in patients with blood groups A and AB. Hemolysis occurred more frequently in patients treated with IVIG for some conditions such as Kawasaki disease; however, this may be confounded by the high dose of IVIG therapy. IVIG‐related hemolysis incidence was lower in studies using IVIG products citing manufacturing processes to reduce isoagglutinin levels than products that did not.

Conclusion

This analysis identified patient and product risk factors including blood group, IVIG dose, and IVIG manufacturing processes associated with elevated IVIG‐related hemolysis incidence.

Immunoglobulin for multifocal motor neuropathy

BACKGROUND

Multifocal motor neuropathy (MMN) is a rare, probably immune-mediated disorder characterised by slowly progressive, asymmetric, distal weakness of one or more limbs with no objective loss of sensation. It may cause prolonged periods of disability. Treatment options for MMN are few. People with MMN do not usually respond to steroids or plasma exchange. Uncontrolled studies have suggested a beneficial effect of intravenous immunoglobulin (IVIg). This is an update of a Cochrane Review first published in 2005, with an amendment in 2007. We updated the review to incorporate new evidence.

OBJECTIVES

To assess the efficacy and safety of intravenous and subcutaneous immunoglobulin in people with MMN.

SEARCH METHODS

We searched the following databases on 20 April 2021: the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and WHO ICTRP for randomised controlled trials (RCTs) and quasi-RCTs, and checked the reference lists of included studies.

SELECTION CRITERIA

We considered RCTs and quasi-RCTs examining the effects of any dose of IVIg and subcutaneous immunoglobulin (SCIg) in people with definite or probable MMN for inclusion in the review. Eligible studies had to have measured at least one of the following outcomes: disability, muscle strength, or electrophysiological conduction block. We used studies that reported the frequency of adverse effects to assess safety.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed the literature searches to identify potentially relevant trials, assessed risk of bias of included studies, and extracted data. We followed standard Cochrane methodology.

MAIN RESULTS

Six cross-over RCTs including a total of 90 participants were suitable for inclusion in the review. Five RCTs compared IVIg to placebo, and one compared IVIg to SCIg. Four of the trials comparing IVIg versus placebo involved IVIg-naive participants (induction treatment). In the other two trials, participants were known IVIg responders receiving maintencance IVIg at baseline and were then randomised to maintenance treatment with IVIg or placebo in one trial, and IVIg or SCIg in the other. Risk of bias was variable in the included studies, with three studies at high risk of bias in at least one risk of bias domain. IVIg versus placebo (induction treatment): three RCTs including IVIg-naive participants reported a disability measure. Disability improved in seven out of 18 (39%) participants after IVIg treatment and in two out of 18 (11%) participants after placebo (risk ratio (RR) 3.00, 95% confidence interval (CI) 0.89 to 10.12; 3 RCTs, 18 participants; low-certainty evidence). The proportion of participants with an improvement in disability at 12 months was not reported. Strength improved in 21 out of 27 (78%) IVIg-naive participants treated with IVIg and one out of 27 (4%) participants who received placebo (RR 11.00, 95% CI 2.86 to 42.25; 3 RCTs, 27 participants; low-certainty evidence). IVIg treatment may increase the proportion of people with resolution of at least one conduction block; however, the results were also consistent with no effect (RR 7.00, 95% CI 0.95 to 51.70; 4 RCTs, 28 participants; low-certainty evidence). IVIg versus placebo (maintenance treatment): a trial that included participants on maintenance IVIg treatment reported an increase in disability in 17 out of 42 (40%) people switching to placebo and seven out of 42 (17%) remaining on IVIg (RR 2.43, 95% CI 1.13 to 5.24; 1 RCT, 42 participants; moderate-certainty evidence) and a decrease in grip strength in 20 out of 42 (48%) participants after a switch to placebo treatment compared to four out of 42 (10%) remaining on IVIg (RR 0.20, 95% CI 0.07 to 0.54; 1 RCT, 42 participants; moderate-certainty evidence). Adverse events, IVIg versus placebo (induction or maintenance): four trials comparing IVIg and placebo reported adverse events, of which data from two studies could be meta-analysed. Transient side effects were reported in 71% of IVIg-treated participants versus 4.8% of placebo-treated participants in these studies. The pooled RR for the development of side effects was 10.33 (95% CI 2.15 to 49.77; 2 RCTs, 21 participants; very low-certainty evidence). There was only one serious side effect (pulmonary embolism) during IVIg treatment. IVIg versus SCIg (maintenance treatment): the trial that compared continuation of IVIg maintenance versus SCIg maintenance did not measure disability. The evidence was very uncertain for muscle strength (standardised mean difference 0.08, 95% CI -0.84 to 1.00; 1 RCT, 9 participants; very low-certainty evidence). The evidence was very uncertain for the number of people with side effects attributable to treatment (RR 0.50, 95% CI 0.18 to 1.40; 1 RCT, 9 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

Low-certainty evidence from three small RCTs shows that IVIg may improve muscle strength in people with MMN, and low-certainty evidence indicates that it may improve disability; the estimate of the magnitude of improvement of disability has wide CIs and needs further studies to secure its significance. Based on moderate-certainty evidence, it is probable that most IVIg responders deteriorate in disability and muscle strength after IVIg withdrawal. SCIg might be an alternative treatment to IVIg, but the evidence is very uncertain. More research is needed to identify people in whom IVIg withdrawal is possible and to confirm efficacy of SCIg as an alternative maintenance treatment.

An international multicenter efficacy and safety study of IqYmune in initial and maintenance treatment of patients with chronic inflammatory demyelinating polyradiculoneuropathy: PRISM study

This prospective, multicenter, single‐arm, open‐label phase 3 study aimed to evaluate the efficacy and safety of IqYmune in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Patients received one induction dose of 2 g/kg and then seven maintenance doses of 1 g/kg at 3‐week intervals. The primary endpoint was the responder rate at the end of study (EOS), defined as an improvement of ≥1 point on the adjusted inflammatory neuropathy cause and treatment (INCAT) disability scale. The responder rate was compared with the responder rate of a historical placebo group (33.3%). Secondary endpoints included changes from baseline to EOS of adjusted INCAT disability score, grip strength, Medical Research Council (MRC) sum score, Rasch‐modified MRC sum score, Rasch‐built overall disability scale score and the clinical global impression. Forty‐two patients, including 23 Ig‐naïve and 19 Ig‐pre‐treated, were included in the efficacy set. The overall response rate at EOS was 76.2% (95% confidence interval [60.5%‐87.9%]). The superiority of IqYmune compared to the historical placebo control was demonstrated (P < .0001). The responder rate was numerically higher in Ig‐pre‐treated than in Ig‐naïve patients but confidence intervals were overlapping (84.2% [60.4%‐96.6%] vs 69.6% [47.1%‐86.8%]). All secondary endpoints confirmed this conclusion. The median time to response was 15 weeks [8.9‐19.1 weeks]. A total of 156 adverse events including five serious were considered related to IqYmune, 87.2% were mild. Neither hemolysis nor signs of renal or hepatic impairment were observed. These results demonstrate that IqYmune is an effective and well‐tolerated treatment in patients with CIDP.

IqYmune® is an effective maintenance treatment for multifocal motor neuropathy: A randomised, double-blind, multi-center cross-over non-inferiority study vs Kiovig®-The LIME Study

Intravenous immunoglobulin (IVIg) is the gold‐standard for maintenance treatment of multifocal motor neuropathy (MMN). This phase III, randomised, double‐blind, multi‐centre, active‐control, crossover study, aimed to evaluate the non‐inferiority of IqYmune® relative to Kiovig®, primarily based on efficacy criteria. Twenty‐two adult MMN patients, treated with any brand of IVIg (except Kiovig® or IqYmune®) at a stable maintenance dose within the range of 1 to 2 g/kg every 4 to 8 weeks, were randomised to receive either Kiovig® followed by IqYmune®, or IqYmune® followed by Kiovig®. Each product was administered for 24 weeks. The primary endpoint was the difference between IqYmune® and Kiovig® in mean assessments of modified Medical Research Council (MMRC) 10 sum score (strength of 5 upper‐limb and 5 lower‐limb muscle groups, on both sides, giving a score from 0 to 100) during the evaluation period (non‐inferiority margin of Δ = 2). A linear mixed model analysis demonstrated the non‐inferiority of IqYmune® relative to Kiovig®, independently of the covariates (value at baseline, treatment period, and treatment sequence). The estimated “IqYmune® − Kiovig®” difference was −0.01, with a 95% confidence interval (CI) −0.51 to 0.48. The number of adverse reactions (ARs) and the percentage of patients affected were similar for the two products: 39 ARs in 10 patients with IqYmune® vs 32 ARs in 11 patients with Kiovig®. No thromboembolic events nor haemolysis nor renal impairment were observed. In this first clinical trial comparing two IVIg brands for maintenance treatment of MMN, efficacy and tolerability of both brands were similar.