Long-Term Efficacy and Safety of Hizentra® in Patients with Primary Immunodeficiency in Japan, Europe, and the United States: a Review of 7 Phase 3 Trials

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.

Safety and Efficacy of Hizentra® Following Pediatric Hematopoietic Cell Transplant for Treatment of Primary Immunodeficiencies

Primary immunodeficiency disease (PIDD) comprises a group of disorders of immune function. Some of the most severe PIDD can be treated with hematopoietic cell transplant (HCT). Hizentra® is a 20% liquid IgG product approved for subcutaneous administration in adults and children greater than 2 years of age with PIDD-associated antibody deficiency. Limited information is available on the use of Hizentra® in children following HCT for PIDD. A multicenter retrospective chart review demonstrated 37 infants and children (median age 70.1 [range 12.0 to 176.4] months) with PIDD treated by HCT who received Hizentra® infusions over a median duration of 31 (range 4-96) months post-transplant. The most common indication for HCT was IL2RG SCID (n = 16). Thirty-two patients switched from IVIG to SCIG administration, due to one or more of the following reasons: patient/caregiver (n = 17) or physician (n = 12) preference, discontinuation of central venous catheter (n = 16), desire for home infusion (n = 12), improved IgG serum levels following lower levels on IVIG (n = 10), and loss of venous access (n = 8). Serious bacterial infections occurred at a rate of 0.041 per patient-year while on therapy. Weight percentile increased by a mean of 16% during the observation period, with females demonstrating the largest gains. Mild local reactions were observed in 24%; 76% had no local reactions. One serious adverse event (death from sepsis) was reported. Hizentra® was discontinued in 15 (41%) patients, most commonly due to recovery of B cell function (n = 11). These data demonstrate that Hizentra® is a safe and effective option in children who have received HCT for PIDD.

Monoclonal antibody and protein therapeutic formulations for subcutaneous delivery: high-concentration, low-volume vs. low-concentration, high-volume

Biologic drugs are used to treat a variety of cancers and chronic diseases. While most of these treatments are administered intravenously by trained healthcare professionals, a noticeable trend has emerged favoring subcutaneous (SC) administration. SC administration of biologics poses several challenges. Biologic drugs often require higher doses for optimal efficacy, surpassing the low volume capacity of traditional SC delivery methods like autoinjectors. Consequently, high concentrations of active ingredients are needed, creating time-consuming formulation obstacles. Alternatives to traditional SC delivery systems are therefore needed to support higher-volume biologic formulations and to reduce development time and other risks associated with high-concentration biologic formulations. Here, we outline key considerations for SC biologic drug formulations and delivery and explore a paradigm shift: the flexibility afforded by low-to-moderate-concentration drugs in high-volume formulations as an alternative to the traditionally difficult approach of high-concentration, low-volume SC formulation delivery.

Long-term efficacy, safety, and tolerability of a subcutaneous immunoglobulin 16.5% (cutaquig®) in the treatment of patients with primary immunodeficiencies

A prospective study and its long-term extension examined whether weekly treatment of patients with primary immunodeficiencies (PIDs) with a 16.5% subcutaneous immunoglobulin (SCIg; cutaquig®) confers acceptable efficacy, safety, and tolerability over a follow-up of up to 238 weeks (>4 years). Seventy-five patients received 4462 infusions during up to 70 weeks of follow-up in the main study and 27 patients received 2777 infusions during up to 168 weeks of follow-up in the extension. In the main study, there were no serious bacterial infections (SBIs), and the annual rate of other infections was 3.3 (95% CI 2.4, 4.5). One SBI was recorded in the extension, for an SBI rate of 0.02 (upper 99% CI 0.19). The annual rate of all infections over the duration of the extension study was 2.2 (95% CI 1.2, 3.9). Only 15.0% (1085) of 7239 infusions were associated with infusion site reactions (ISRs), leaving 85.0% (6153) of infusions without reactions. The majority of ISRs were mild and transient. ISR incidence decreased over time, from 36.9% to 16% during the main study and from 9% to 2.3% during the extension. The incidence of related systemic adverse events was 14.7% in the main study and 7.4% in the extension. In conclusion, this prospective, long-term study with cutaquig showed maintained efficacy and low rates of local and systemic adverse reactions in PID patients over up to 238 weeks of follow-up.

Replacement and Immunomodulatory Activities of 20% Subcutaneous Immunoglobulin Treatment: A Single-Center Retrospective Study in Autoimmune Myositis and CVID Patients

Background

Immunoglobulin (Ig) replacement therapy represents a life-saving treatment in primary antibody deficiencies. The introduction of subcutaneous Ig (SCIg) administration brings a major improvement in quality of life for patients, compared to the traditional intravenous administration. In recent years, an additional role has been proposed for Ig therapy for various inflammatory and immune-mediated diseases. Consequently, the use of SCIg has expanded from immunodeficiencies to immune-mediated diseases, such as polymyositis (PM) and dermatomyositis (DM). Given the rarity of these conditions, it is still difficult to evaluate the real impact of SCIg treatment on PM and DM, and additional data are constantly required on this topic, particularly for long-term treatments in real-life settings.

Aim

This study aimed to increase the knowledge about the anti-inflammatory and immunomodulatory effects of SCIg treatment for myositis. To this aim, a long-term evaluation of the effectiveness of 20% human SCIg treatment (20% SCIg, Hizentra^®, CSL Behring) was carried out in patients with PM/DM in care at our Center. In addition, an evaluation of the 20% SCIg therapy in CVID patients was provided. This analysis, beside adding knowledge about the use of SCIg therapy in this real-life setting, was intended as a term of comparison, regarding the safety profile.

Results

Results support the beneficial effect and tolerability of long-term 20% SCIg therapy in PM/DM patients, reporting a significant improvement in creatine kinase levels, muscle strength, skin conditions, dysphagia, disease activity (MITAX score) and disability (HAQ-DI score). None of the patients reported systemic reactions. The duration of the reported local reactions was a few hours in 80% of the patients, and all resolved spontaneously. CVID patients reported an improvement in all the considered effectiveness parameters at the end of 20% SCIg therapy. The frequency of the adverse events reported by PM/DM patients was not different from what reported in CVID patients, where the use of SCIg therapy is more consolidated

Conclusions

This study suggests that 20% SCIg treatment represents a viable and safe treatment for PM/DM patients and a valid therapeutic alternative to IVIg, with important advantages for patients’ quality of life.

Real-world results with IgPro20 for hypo- or agammaglobulinemia in Japan

BACKGROUND

Subcutaneous immunoglobulin is one of the standard treatments for hypogammaglobulinemia in primary immunodeficiencies (PID) worldwide. In Japan, IgPro20 (Hizentra^® ; l-proline-stabilized 20% human subcutaneous immunoglobulin) is approved for agammaglobulinemia or hypogammaglobulinemia due to PID or secondary immunodeficiency (SID); however, its safety and effectiveness has not previously been assessed in a real-world setting.

METHODS

This multicenter, open label post-marketing surveillance study was conducted between January 2014 and March 2019. Patients who received IgPro20 due to PID or SID were included after informed consent. Physicians completed a case report form for each patient. Safety was determined from reported adverse events (AEs), adverse drug reactions, and serious AEs (SAEs); effectiveness was assessed by infection rates after the first IgPro20 dose.

RESULTS

Of 85 patients receiving IgPro20 in the safety analysis, 39 developed AEs (45.9%; PID n = 28, SID n = 11). At least one adverse drug reaction was observed in 27 patients (31.8%; PID n = 21, SID n = 6), and the most common were injection site reactions (n = 17, 20.0%). Four patients (PID n = 3, SID n = 1) reported SAEs but two were unrelated to IgPro20 administration. The infection rate decreased from 0.54 per patient during the 6 months before IgPro20 to 0.39 per patient during IgPro20 treatment. Serious bacterial infections occurred in six patients before IgPro20 (7.9%; PID n = 2; SID n = 4) but in only one patient with SID during IgPro20 treatment (1.2%).

CONCLUSIONS

In Japan, IgPro20 was considered safe and effective among patients with agammaglobulinemia or hypogammaglobulinemia due to PID or SID.

Reducing Delays in Diagnosing Primary Immunodeficiency Through the Development and Implementation of a Clinical Decision Support Tool: A Study Protocol

Background

Primary immunodeficiencies (PIs) are a set of heterogeneous chronic disorders characterized by immune dysfunction. They are diagnostically challenging because of their clinical heterogeneity, knowledge gaps among primary care physicians, and continuing shortages of clinically trained immunologists. As a result, patients with undiagnosed PIs are at increased risk for recurrent infections, cancers, and autoimmune diseases.

Objective

The aim of this research is to develop and implement a clinical decision support (CDS) tool for the identification of underlying PIs.

Methods

We will develop and implement a CDS tool for the identification of underlying PIs among patients who receive primary care through a health care provider at the University of Iowa Hospitals and Clinics. The CDS tool will function through an algorithm that is based on the Immune Deficiency Foundation’s 10 Warning Signs for Primary Immunodeficiency. Over the course of a year, we will use Lean Six Sigma principles and the Define, Measure, Analyze, Improve, and Control (DMAIC) framework to guide the project. The primary measure is the number of newly diagnosed PI patients per month. Secondary measures include the following: (1) the number of new patients identified by the CDS as being at high risk for PI, (2) the number of new PI cases in which immunoglobulin replacement or rotating antibiotics are started, (3) the cost of evaluation of each patient identified by the CDS tool as being at high risk for PIs, (4) the number of new consults not diagnosed with a PI, and (5) patient satisfaction with the process of referral to the Immunology Clinic.

Results

This study was determined to not be Human Subjects Research by the Institutional Review Board at the University of Iowa. Data collection will begin in August 2021.

Conclusions

The development and implementation of a CDS tool is a promising approach to identifying patients with underlying PI. This protocol assesses whether such an approach will be able to achieve its objective of reducing diagnostic delays. The disciplined approach, using Lean Six Sigma and the DMAIC framework, will guide implementation to maximize opportunities for a successful intervention that meets the study’s goals and objectives as well as to allow for replication and adaptation of these methods at other sites.

International Registered Report Identifier (IRRID)

PRR1-10.2196/32635

Treatment of children with primary immunodeficiencies with a subcutaneous immunoglobulin 16.5% (cutaquig® [octanorm])

Background: Subcutaneous human immunoglobulin (16.5%; octanorm/cutaquig^®) was efficacious and well tolerated in patients with primary immunodeficiencies in a Phase III study. A subanalysis of pediatric data is presented here. Materials & methods: Children (2-16 years) previously treated with intravenous human immunoglobulin received weekly subcutaneous human immunoglobulin infusions over 64 weeks. The main objective was to assess the efficacy of cutaquig in preventing serious bacterial infections. Results: 38 children received 2213 infusions of cutaquig. No serious bacterial infections developed during the study. The rate of other infections was 3.1 per person-year and the rate of adverse drug reactions was 0.083 per infusion. Higher immunoglobulin G trough levels were achieved with cutaquig compared with previous intravenous therapy. Conclusion: Once-weekly infusions of cutaquig were efficacious and well tolerated in children with primary immunodeficiencies.

Individualizing Therapy in CIDP: A Mini-Review Comparing the Pharmacokinetics of Ig With SCIg and IVIg

Immunoglobulin (Ig) therapy is a first-line treatment for CIDP, which can be administered intravenously (IVIg) or subcutaneously (SCIg) and is often required long term. The differences between these modes of administration and how they can affect dosing strategies and treatment optimization need to be understood. In general, the efficacy of IVIg and SCIg appear comparable in CIDP, but SCIg may offer some safety and quality of life advantages to some patients. The differences in pharmacokinetic (PK) profile and infusion regimens account for many of the differences between IVIg and SCIg. IVIg is administered as a large bolus every 3–4 weeks resulting in cyclic fluctuations in Ig concentration that have been linked to systemic adverse events (AEs) (potentially caused by high Ig levels) and end of dose “wear-off” effects (potentially caused by low Ig concentration). SCIg is administered as a smaller weekly, or twice weekly, volume resulting in near steady-state Ig levels that have been linked to continuously maintained function and reduced systemic AEs, but an increase in local reactions at the infusion site. The reduced frequency of systemic AEs observed with SCIg is likely related to the avoidance of high Ig concentrations. Some small studies in immune-mediated neuropathies have focused on serum Ig data to evaluate its potential use as a biomarker to aid clinical decision-making. Analyzing dose data may help understand how establishing and monitoring patients' Ig concentration could aid dose optimization and the transition from IVIg to SCIg therapy.

Subcutaneous immunoglobulin in allogeneic hematopoietic cell transplant patients: A prospective study of feasibility, safety, and healthcare resource use

BACKGROUND

We evaluated feasibility, safety, and total resource use of subcutaneous immunoglobulin (SCIG) in a pilot study of patients who underwent allogeneic hematopoietic cell transplant (HCT) over a 6-month period.

METHODS

A total of 20 eligible patients were treated with SCIG at 0.1 g/kg/week for up to 6 months. Patients were matched to 20 concurrent intravenous immunoglobulin (IVIG) controls. Clinical outcomes measured included adverse reactions, healthcare resource use, patient satisfaction, and quality of life (QOL). (ClinicalTrials.gov Identifier: NCT03401268.) RESULTS: Groups were comparable in terms of age, weight, sex, transplant indication, donor type, and conditioning intensity. All 20 IVIG patients completed 6 consecutive months of therapy compared with 13/20 (65%) SCIG patients. There were no adverse reactions in IVIG patients, compared with six (30%) SCIG patients. All adverse reactions in SCIG patients were grade I, transient, and required no medical intervention. Median overall cost per patient was lower with SCIG than with IVIG ($9,756 vs. $13,780, p = .046). Among patients who completed 6 months of SCIG, median preference and satisfaction scores were 100%. Over the 6-month period, QOL scores remained stable in SCIG patients.

CONCLUSIONS

In a subgroup of patients, SCIG was associated with high patient satisfaction and a reduction in total healthcare costs compared with IVIG in a cohort of HCT patients.

Safety and Tolerability of Manual Push Administration of Subcutaneous IgPro20 at High Infusion Rates in Patients with Primary Immunodeficiency: Findings from the Manual Push Administration Cohort of the HILO Study

Purpose

To evaluate the safety and tolerability of IgPro20 manual push (also known as rapid push) infusions at flow rates of 0.5–2.0 mL/min.

Methods

Patients with primary immunodeficiency (PID) with previous experience administering IgPro20 (Hizentra^®, CSL Behring, King of Prussia, PA, USA) were enrolled in the Hizentra^® Label Optimization (HILO) study (NCT03033745) and assigned to Pump-assisted Volume Cohort, Pump-assisted Flow Rate Cohort, or Manual Push Flow Rate Cohort; this report describes the latter. Patients administered IgPro20 via manual push at 0.5, 1.0, and 2.0 mL/min/site for 4 weeks each. Responder rates (percentage of patients who completed a predefined minimum number of infusions), safety outcomes, and serum immunoglobulin G (IgG) trough levels were evaluated.

Results

Sixteen patients were treated; 2 patients (12.5%) discontinued at the 1.0-mL/min level (unrelated to treatment). Responder rates were 100%, 100%, and 87.5% at 0.5-, 1.0-, and 2.0-mL/min flow rates, respectively. Mean weekly infusion duration decreased from 103–108 to 23–28 min at the 0.5- and 2.0-mL/min flow rates, respectively. Rates of treatment-related treatment-emergent adverse events (TEAEs) per infusion were 0.023, 0.082, and 0.025 for the 0.5-, 1.0-, and 2.0-mL/min flow rates, respectively. Most TEAEs were mild local reactions and tolerability (infusions without severe local reactions/total infusions) was 100% across flow rate levels. Serum IgG levels (mean [SD]) were similar at study start (9.36 [2.53] g/L) and end (9.58 [2.12] g/L).

Conclusions

Subcutaneous IgPro20 manual push infusions at flow rates up to 2.0 mL/min were well tolerated and reduced infusion time in treatment-experienced patients with PID.

Trial Registration

NCT03033745

Electronic supplementary material

The online version of this article (10.1007/s10875-020-00876-6) contains supplementary material, which is available to authorized users.

Pediatric subset of primary immunodeficiency patients treated with SCIG: post hoc analysis of SHIFT and IBIS pooled data

Background

Primary immunodeficiencies (PID) constitute a heterogeneous group of more than 350 monogenetic diseases. PID patients with antibody impairment require lifelong administration of immunoglobulin G replacement therapy, administered either intravenously (IVIG) or subcutaneously (SCIG). Although the effectiveness of weekly and biweekly (every other week) SCIG administration has been shown in several trials, data on the viability of these two regimens in pediatric PID patients are sparse.

Methods

Data on the pediatric subsets of PID patients enrolled in SHIFT (weekly) and IBIS (biweekly) studies were pooled and analyzed to indirectly compare two different 20%-concentrated SCIG (Hizentra^®) regimens. The primary endpoints were to evaluate trough IgG levels and cumulative monthly doses; the secondary endpoint was to analyze incidence of infections.

Results

Fifteen and 13 children from the SHIFT and IBIS studies were included, respectively. Cumulative 20%-concentrated SCIG monthly dose was slight lower for the biweekly regimen (Δ = − 2.04, 90% CI − 8.3 to 4.23). However, the trough IgG levels were similar between the two groups (Δ = 0.28, 90% CI − 0.51 to 1.07) and constantly above the threshold of 5 g/L. After adjusting for potential confounders, the annualized rate of infections was similar between SHIFT and IBIS patients (incidence rate ratio = 1.09, 90% CI 0.72–1.67); only 1 serious bacterial infection was experienced by a patient in the IBIS group.

Conclusion

In pediatric PID patients, weekly and biweekly Hizentra^® administrations appeared equally effective treatment options.

Delivery of subcutaneous immunoglobulin by rapid "push" infusion for primary immunodeficiency patients in Manitoba: a retrospective review

Background

Both intravenous and subcutaneous human immune globin G (IgG) replacement (IVIG and SCIG, respectively) reduce severe infection and increase serum IgG levels in primary immune deficiency disorder (PIDD) patients who require replacement. SCIG can be administered either with the aid of an infusion pump, or by patients or caregivers themselves, using butterfly needles and a syringe (“SCIG push”). SCIG offers advantages over IVIG, including higher steady state IgG levels, improved patient quality of life indicators, and decreased cost to the healthcare system, and for these reasons, SCIG has been increasingly used in Manitoba starting in 2007. We sought to determine the effectiveness of SCIG push in our local adult PIDD population.

Methods

We conducted a retrospective chart review of all adult patients enrolled in the SCIG push program in Manitoba, Canada from its inception in November 2007 through September 2018. We included patients who were naïve to IgG replacement prior to SCIG, and those who had received IVIG immediately prior. We collected data regarding serum IgG levels, antibiotic prescriptions, hospital admissions, and adverse events during a pre-defined period prior to and following SCIG initiation. Statistical significance was determined via two-tailed t-test.

Results

62 patients met inclusion criteria, of whom 35 were on IVIG prior and 27 were IgG replacement naïve. SCIG push resulted in an increase in serum IgG levels in those naïve to IgG replacement, as well as in those who received IVIG prior. SCIG push also resulted in a statistically significant reduction in number of antibiotic prescriptions filled in the naïve subgroup, and no significant change in antibiotics filled in the IVIG prior group. 8/62 PIDD patients (12.9%) left the SCIG program during our review period for varying reasons, including side-effects.

Conclusions

In a real-life setting, in the Manitoba adult PIDD population, SCIG push is an effective method of preventing severe infections, with most patients preferring to continue this therapy once initiated.

Long-term efficacy, safety, and tolerability of recombinant human hyaluronidase-facilitated subcutaneous infusion of immunoglobulin (Ig) (fSCIG; HyQvia(®)) in immunodeficiency diseases: real-life data from a monocentric experience

Humoral immunodeficiency diseases represent a heterogeneous group of disorders that require long-term therapies. Thus, the treatment provided must not only be effective but also safe and well tolerated. In this paper, we report our data on the efficacy, safety, and tolerability of recombinant human hyaluronidase-facilitated subcutaneous infusion of immunoglobulin (Ig) (fSCIG; HyQvia(^®)) in immunodeficiency patients. We collected retrospective data from 30 patients with primary and secondary immunodeficiency diseases in therapy with fSCIG from September 2014 to December 2019. We evaluated the efficacy of the therapy, taking into account serum IgG values during follow-up and the number of annual infectious events and serious bacterial infections reported by patients. Safety was assessed on the basis of the number and intensity of adverse events (AEs) and local reactions reported. Our real-life data suggest that long-term repeated self-administration of recombinant human hyaluronidase-facilitated subcutaneous infusion of immunoglobulins results in a reduced rate of infectious events if compared to the pre-treatment rate. Both AEs and local reactions are mild to moderate and were never reasons for treatment discontinuation. Therapy with HyQvia shows prolonged efficacy and good tolerability; these aspects, together with the possibility of self-administration at home, minimize the impact the illness has on patients.

Pharmacokinetic Analysis of Weekly Versus Biweekly IgPro20 Dosing in Patients With Primary Immunodeficiency

Flexible dosing of IgPro20 (Hizentra®, CSL Behring, King of Prussia, Pennsylvania) maintains normal serum immunoglobulin G (IgG) levels in patients with primary immunodeficiencies (PID). Until now, clinical trials testing the pharmacokinetic (PK) characteristics of serum IgG of weekly and biweekly subcutaneous IgG therapy were not published. This is the first study assessing PK characteristics following weekly and biweekly IgPro20 in patients with PID. The PK study was conducted in 2 parts: weekly dosing (12 weeks) and biweekly dosing (up to 12 months). Serum IgG concentration-time data were analyzed using noncompartmental methods to generate PK parameters. Fifteen patients provided PK samples for both dosing regimens. For weekly and biweekly regimens, mean doses per infusion were 109 and 213 mg/kg, respectively, and median t_max was 2.0 and 3.02 days, respectively. The mean C_trough values were similar in weekly and biweekly regimens (10.21 and 10.13 g/dL, respectively). The geometric mean ratios (GMRs) with 90% confidence intervals of biweekly to weekly C_max and C_trough were 1.10 (1.06-1.13) and 0.98 (0.95-1.01), respectively. The GMR of dAUC was 1.07 (1.03-1.10). This PK analysis demonstrated similar systemic IgG exposure after weekly and biweekly IgPro20 dosing with an equivalent monthly dose in patients with PID.

Czech Hizentra Noninterventional Study With Rapid Push: Efficacy, Safety, Tolerability, and Convenience of Therapy With 20% Subcutaneous Immunoglobulin

PURPOSE

Immunoglobulin substitution therapy is an essential therapeutic approach for patients with primary antibody deficiencies. Different methods of administration, including intravenous immunoglobulin (IVIG) or subcutaneous immunoglobulin (SCIG) preparations, provide effective and tolerable treatment and enable the adjustment of therapy to patients' needs. A new 20% SCIG represents a new therapeutic option and a new route of administration using rapid-push application. The aim of the Czech Hizentra Noninterventional Study With Rapid Push (CHHINSTRAP) is to evaluate patient satisfaction with as well as the tolerability and efficacy of nonmedical switch to 20% SCIG from previous treatment with IVIG or SCIG and rapid push as a new way to administer SCIG. CHHINSTRAP is the first Phase IV, noninterventional, open-label, prospective, multicentric study of this type conducted in Central and Eastern Europe.

METHODS

Primary end points, including efficacy, adverse effects, convenience of use, and overall satisfaction, were evaluated by Treatment Satisfaction Questionnaire for Medication version II. Secondary end points, such as serum IgG trough levels, infusion duration, number of application sites, frequency of infections, related hospital admissions, and antibiotic consumption, were obtained from patients at each follow-up visit.

FINDINGS

Together, 50 eligible patients with primary antibody deficiency were switched from SCIG or IVIG to an equivalent dose of 20% SCIG and were followed up for 12 months during 5 consecutive visits. The results indicate that patients switched from previous IVIG or SCIG preparations had significantly higher serum trough IgG levels and a lower incidence of infections and related events, such as hospital admissions or consumption of antibiotics. These findings were also reflected in gradually increasing convenience of use and overall satisfaction reported by patients. Apart from duration of application, no differences were found between patients previously receiving SCIG or IVIG. Moreover, our study found a high level of safety of 20% SCIG rapid push, which was comparable to other preparations and application methods.

IMPLICATIONS

On the basis of the results of CHHINSTRAP study, we conclude that 20% SCIG is a tolerable and effective immunoglobulin preparation, representing a new therapeutic approach in patients with primary antibody deficiencies. Its efficacy and tolerability have been found in patients on nonmedical switch from previous treatment with IVIG or SCIG.