Patient‐reported outcomes with subcutaneous immunoglobulin in chronic inflammatory demyelinating polyneuropathy: the PATH study

Feasibility and Tolerability of Subcutaneous Immunoglobulin via Manual Push Pre-Filled Syringes for Inflammatory Neuropathies: A Retrospective Cohort Study

INTRODUCTION/AIMS

Subcutaneous immunoglobulin (SCIG) is available as vials or pre-filled syringes (PFS) and can be administered via pump or manual push to treat inflammatory neuropathies, such as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). There are limited data on PFS-SCIG manual push in this population, and this administration method may be perceived as challenging as large volumes of SCIG are required for immunomodulation. Here, we evaluated the feasibility of PFS-manual push SCIG in patients with inflammatory neuropathies.

METHODS

Patients with inflammatory neuropathies receiving immunoglobulin therapy in a single center were identified via the National Immunoglobulin Database. Case notes were retrospectively evaluated for patient characteristics and immunoglobulin use data.

RESULTS

Thirty-six patients with inflammatory neuropathies being treated with PFS-SCIG were identified (CIDP: n = 29; multifocal motor neuropathy: n = 2; other: n = 5). Overall, 27 patients initiated SCIG with PFS-manual push. The remaining patients initiated SCIG with PFS-pump administration but, during the study, most (n = 7) switched to PFS-manual push, while one switched from PFS-manual push to PFS-pump. Five patients experienced adverse events, mostly associated with infusion-site swelling that could be managed by reducing infusion rates. Patient perception of PFS-manual push was positive, with multiple patients commenting on its convenience.

DISCUSSION

PFS-manual push SCIG appeared to be feasible and generally well-tolerated in patients with inflammatory neuropathies. Further studies should confirm PFS-SCIG manual push as a viable option for patients with inflammatory neuropathies and explore whether PFS might enhance treatment satisfaction and quality of life.

Patient-reported preferences for subcutaneous or intravenous administration of parenteral drug treatments in adults with immune disorders: a systematic review and meta-analysis

Aim: Several studies have found subcutaneous (SC) and intravenous (IV) administration of similar drugs for long-lasting immunological and autoimmune diseases to have similar clinical effectiveness, meaning that what patients report they prefer is, or should be, a major factor in treatment choices. Therefore, it is important to systematically compile evidence regarding patient preferences, treatment satisfaction and health-related quality of life (HRQL) using SC or IV administration of the same drug. Materials & methods: PubMed database searches were run on 15 October 2021. Studies involving patients with experience of both home-based SC and hospital-based IV administration of immunoglobulins or biological therapies for the treatment of any autoimmune disease or primary immunodeficiencies (PIDs) were included. The outcomes assessed were patient preferences, treatment satisfaction and HRQL. Preference data were meta-analyzed using a random-effects model. Results: In total, 3504 citations were screened, and 46 publications describing 37 studies were included in the review. There was a strong overall preference for SC over IV administration, with similar results seen for PIDs and autoimmune diseases: PID, 80% (95% confidence interval [CI], 64-94%) preferred SC; autoimmune diseases, 83% (95% CI: 73-92%); overall, 82% (95% CI: 75-89%). The meta-analysis also found that 84% (95% CI: 75-92%) of patients preferred administration at home to treatment in hospital. Analysis of treatment satisfaction using the life quality index found consistently better treatment interference and treatment setting scores with SC administration than with IV administration. Conclusion: Compared with IV infusions in hospital, patients tend to prefer, to be more satisfied with and to report better HRQL with SC administration of the same drug at home, primarily due to the greater convenience. This study contributes to evidence-based care of patients with autoimmune diseases or PIDs.

The impact of myasthenia gravis severity on work and daily activities

INTRODUCTION/AIMS

People with myasthenia gravis (MG) experience impaired quality of life. However, the impact of MG symptoms on work productivity has not been well-studied. We aimed to evaluate this impact and to examine associations between disease severity and the degree of impairment.

METHODS

Data were drawn from the Adelphi MG Disease-Specific Programme™, a multinational (USA, France, Germany, Italy, Spain, UK) survey completed by physicians and their patients with MG in 2020. Patient-reported measures included the Work Productivity and Activity Impairment (WPAI): Specific Health Problem questionnaire.

RESULTS

The WPAI questionnaire was completed by 330 patients. Among those currently employed, the mean percentage of work time missed (absenteeism) was 13.3% (N = 116), percentage impairment of productivity at work (presenteeism) was 26.7% (N = 121), and overall work impairment was 30.0% (N = 110). Across all patients, impairment of non-work-related activities due to health problems (ADL impairment) was 39.2% (N = 330). Regression analysis indicated that impairment differed according to MG Foundation of America (MGFA) class (p = .0147, p < .0001, p < .0001 and p < .0001 for absenteeism, presenteeism, overall work impairment and ADL impairment, respectively). Being MGFA class III/IV was a predictor of presenteeism, overall work impairment and ADL impairment in a predictor model.

DISCUSSION

Patients with MG experience substantial work impairment particularly those with more severe symptoms, highlighting an important way in which patient quality of life is negatively affected. More effective treatment strategies would enable patients to lead more productive lives and could impact decisions relating to work and career.

Subcutaneous Immunoglobulin in Chronic Inflammatory Demyelinating Polyneuropathy: A Historical Perspective

The therapeutic administration of subcutaneous immunoglobulin (SCIg) offers various advantages over intravenous immunoglobulin (IVIg). This narrative review examines and compares SCIg versus IVIg in chronic inflammatory demyelinating polyneuropathy (CIDP). SCIg is as effective as IVIg but is better tolerated and easier to administer, as intravenous access is not required. Furthermore, SCIg administration is more convenient and cost-effective than IVIg, enabling flexible treatment scheduling at home and improving patients' overall quality of life. The availability of highly concentrated immunoglobulin G (IgG) subcutaneous solutions, such as IgPro20, a 20% IgG solution stabilized with L-proline, allows for the administration of larger volumes in a single session, while the parallel development of new technological devices enables the delivery of higher doses over a shorter time. Based on the results of the PATH study, SCIg has become a well-established therapy in CIDP. In addition to discussing the advantages of SCIg, this review summarizes the evolution of SCIg by discussing all the relevant clinical studies which have considered its use in the treatment of CIDP.

Pain-resolving immune mechanisms in neuropathic pain

Interactions between the immune and nervous systems are of central importance in neuropathic pain, a common and debilitating form of chronic pain caused by a lesion or disease affecting the somatosensory system. Our understanding of neuroimmune interactions in pain research has advanced considerably. Initially considered as passive bystanders, then as culprits in the pathogenesis of neuropathic pain, immune responses in the nervous system are now established to underpin not only the initiation and progression of pain but also its resolution. Indeed, immune cells and their mediators are well-established promoters of neuroinflammation at each level of the neural pain pathway that contributes to pain hypersensitivity. However, emerging evidence indicates that specific subtypes of immune cells (including antinociceptive macrophages, pain-resolving microglia and T regulatory cells) as well as immunoresolvent molecules and modulators of the gut microbiota-immune system axis can reduce the pain experience and contribute to the resolution of neuropathic pain. This Review provides an overview of the immune mechanisms responsible for the resolution of neuropathic pain, including those involved in innate, adaptive and meningeal immunity as well as interactions with the gut microbiome. Specialized pro-resolving mediators and therapeutic approaches that target these neuroimmune mechanisms are also discussed.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Measuring, Analyzing, and Presenting Work Productivity Loss in Randomized Controlled Trials: A Scoping Review

OBJECTIVES

This study aimed to conduct a scoping review of randomized controlled trials (RCTs) and investigate which work productivity loss outcomes were measured in these RCTs, how each outcome was measured and analyzed, and how the results for each outcome were presented.

METHODS

A systematic search was conducted from January 2010 to April 2020 from 2 databases: PubMed and Cochrane Central Register of Controlled Trials. Data on country, study population, disease focus, sample size, work productivity loss outcomes measured (absenteeism, presenteeism, employment status changes), and methods used to measure, report, and analyze each work productivity loss outcome were extracted and analyzed.

RESULTS

We found 435 studies measuring absenteeism or presenteeism, of which 155 studies (35.6%) measured both absenteeism and presenteeism and were included in our final review. Only 9 studies also measured employment status changes. The most used questionnaire was the Work Productivity and Activity Impairment Questionnaire. The analysis of absenteeism and presenteeism data was mostly done using regression models (n = 98, n = 98, respectively) for which a normal distribution was assumed (n = 77, n = 89, respectively). Absenteeism results were most often presented in time whereas presenteeism was commonly presented using a percent scale or score.

CONCLUSIONS

There is a lack of consensus on how to measure, analyze, and present work productivity loss outcomes in RCTs published in the past 10 years. The diversity of measurement, analysis, and presentation methods used in RCTs may make comparability challenging. There is a need for guidelines providing recommendations to standardize the comprehensiveness and the appropriateness of methods used to measure, analyze, and report work productivity loss in RCTs.

Immunoglobulin Use for the Management of Painful Peripheral Neuropathy: A Systematic Review and Meta-Analysis

BACKGROUND

Immunoglobulins (IG) are widely used for the treatment of a variety of immune-mediated diseases. The exact mechanism of action remains unknown, but IG modulate the expression and function of Fc receptors, interfere with complement activation and production of cytokines, neutralize pathogenic autoantibodies, and affect the activation and effector functions of B and T lymphocytes. Immunoglobulins are usually delivered intravenously, and are effective in ameliorating motor symptoms, and/or preventing disease progression in immune-mediated neuropathies, including Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy.

OBJECTIVE

The aim of this systematic review and meta-analysis was to study the potential of IG for the treatment of painful peripheral neuropathy (PPN). The outcome of interest was the percentage of patients with PPN who achieved pain relief following IG administration.

METHODS

We performed a systematic literature search on March 17, 2022, in the PubMed database without any publication date restrictions. We also looked for unpublished or ongoing trials in clinicaltrials.org. Pain reduction following IG treatment had to be within the aims (primary or secondary).

RESULTS

The aforementioned literature search strategy revealed five studies (two open-label, three randomized placebo-controlled) eligible to be included. The pooled estimate of the percentage of patients with PPN who received immunoglobulins and reported pain relief was found to be 65% (95% CI 58-71%). The likelihood of achieving pain relief with immunoglobulin treatment was 2.9 times higher (95% CI 1.6-5.2) compared to placebo (p = 0.0003).

CONCLUSION

The use of IG for the treatment of pain due to peripheral neuropathy has a potential therapeutic benefit. Further studies across patients with different types of painful peripheral neuropathy are needed to better characterize this effect. Registration number on PROSPERO: CRD42022319614.

Subcutaneous immunoglobulin treatment for chronic inflammatory demyelinating polyneuropathy

Immunoglobulin G (IgG) therapy is an established long‐term treatment in chronic inflammatory demyelinating polyneuropathy (CIDP) that is commonly administered intravenously (IVIg). The subcutaneous immunoglobulin (SCIg) administration route is a safe and effective alternative option, approved by the United States Food and Drug Administration (FDA) in 2018, for maintenance treatment of adults with CIDP. Physicians and patients alike need to be aware of all their treatment options in order to make informed decisions and plan long‐term treatment strategies. In this review, we collate the evidence for SCIg in CIDP from all published studies and discuss their implications and translation to clinical practice. We also provide guidance on the practicalities of how and when to transition patients from IVIg to SCIg and ongoing patient support. Evidence suggests that IVIg and SCIg have comparable long‐term efficacy in CIDP. However, SCIg can provide additional benefits for some patients, including no requirement for venous access or premedication, and reduced frequency of systemic adverse events. Local‐site reactions are more common with SCIg than IVIg, but these are mostly well‐tolerated and abate with subsequent infusions. Data suggest that many patients prefer SCIg following transition from IVIg. SCIg preference may be a result of the independence and flexibility associated with self‐infusion, whereas IVIg preference may be a result of familiarity and reliance on a healthcare professional for infusions. In practice, individualizing maintenance dosing based on disease behavior and determining the minimally effective IgG dose for individuals are key considerations irrespective of the administration route chosen.

Impact of subcutaneous immunoglobulin on quality of life in patients with chronic inflammatory demyelinating polyneuropathy previously treated with intravenous immunoglobulin

INTRODUCTION/AIMS

Intravenous immunoglobulin (IVIg) is a common therapy for patients with chronic inflammatory demyelinating polyneuropathy (CIDP). IVIg may cause systemic adverse events (AEs); therefore, infusion of subcutaneous immunoglobulin (SCIg) may be preferred by some patients. In this study we document the experiences of patients transitioning from IVIg to SCIg.

METHODS

Transitioning subjects with CIDP were followed in a 6-month prospective, open-label study. The primary endpoint was percentage of subjects who withdrew for any reason (including significant AEs). The secondary endpoint was symptom progression or relapse requiring a change in management. Quality of life (QOL) and treatment satisfaction were assessed using the Short Form 36-item Health Survey (SF-36), Treatment Satisfaction Questionnaire for Medication (TSQM), and Chronic Acquired Polyneuropathy Patient-Reported Index (CAP-PRI). Efficacy was assessed using the Inflammatory Rasch-built Overall Disability Scale, hand-held dynamometry, limb motor strength testing (LMST), and timed 25-ft walk (T25-FW).

RESULTS

Fifteen CIDP subjects transitioned from IVIg to SCIg. Of these, three (20%) met the primary endpoint and one (7%) met the secondary endpoint. The SF-36 showed a statistically significant improvement for the domain of role limitations-physical after 24 weeks (P = .03), with no significant differences observed in other domains. TSQM and CAP-PRI showed significant differences in favor of SCIg (P = .003 and .02, respectively). No significant differences were observed in efficacy after 24 weeks, except for LMST, which favored SCIg (P = .003). Eight of the 12 study completers (67%) continued with SCIg.

DISCUSSION

Transition to SCIg was associated with maintained efficacy and improved QOL.

Electrophysiological predictors of response to subcutaneous immunoglobulin therapy in chronic inflammatory demyelinating polyneuropathy

OBJECTIVE

To assess axonal function prior to subcutaneous immunoglobulin (SCIG) therapy or placebo in relation to relapse in chronic inflammatory demyelinating polyneuropathy (CIDP) to determine whether axonal damage can predict therapy response.

METHODS

Relapse rates in patients from the Polyneuropathy and Treatment with Hizentra (PATH) study, where patients were treated with placebo or SCIG (IgPro20), were analyzed by baseline (post-intravenous immunoglobulin stabilization) axonal damage (≤1 mV peroneal compound muscle action potential) status.

RESULTS

In patients with non-axonal damage, relapses were significantly higher with placebo (73.0%) than IgPro20 (0.2 g/kg: 39.1%, 0.4 g/kg: 19.2%). In patients with axonal damage, IgPro20 had no effect on relapse (placebo: 25.0%, IgPro20: 0.2 g/kg: 30.0%, 0.4 g/kg: 19.4%). Patients with axonal damage relapsed significantly less on placebo versus non-axonal damage, but they also demonstrated higher baseline disability.

CONCLUSION

Axonal damage may correspond to relapse upon treatment withdrawal; patients with axonal damage relapse less, possibly reflecting poor response to immunoglobulin therapy, while non-axonal damage patients may experience more relapse, perhaps indicating better treatment response.

SIGNIFICANCE

In CIDP patients with axonal loss, immunoglobulin therapy may not be as effective. Assessing axonal damage could help guide therapy, with immunoglobulins ideally used before substantial axonal damage arises.

Quality of life in chronic inflammatory demyelinating polyneuropathy patients treated with subcutaneous immunoglobulin

BACKGROUND

Subcutaneous immunoglobulin (SCIG) is effective treatment of chronic inflammatory demyelinating polyneuropathy (CIDP). Quality of life (QoL) increases following switch from intravenous administration to SCIG, but its correlation with clinical functioning is sparsely studied.

AIMS OF THE STUDY

The aim of this study is to evaluate the correlation between QoL and clinical functioning in CIDP patients treated with SCIG.

METHODS

Danish patients with CIDP with a disease duration <10 years and currently treated with SCIG were eligible for inclusion. QoL was assessed with EQ-5D-5L and disability by the Overall Disability Sum Score (ODSS) and Rasch-built Overall Disability Scale (RODS). Gait performance was evaluated by a 40-meter-walk test (40-MWT) and a 6-spot-step test (6-SST) along with assessment of muscle strength (Medical Research Council score [MRC]). Correlations between QoL and the measured scores were calculated.

RESULTS

Of 92 eligible patients, 44 were included. QoL on the visual analogue scale (VAS) was 65% (range: 15-90) of the level of healthy controls (P = .03) and correlated to impaired gait function by 40-MWT and 6-SST. QoL correlated to RODS and ODSS, whereas there was no correlation with the MRC score.

CONCLUSIONS

In SCIG treated CIDP patients QoL is reduced and correlates to gait performance and disability.