Biweekly Hizentra® in Primary Immunodeficiency: a Multicenter, Observational Cohort Study (IBIS)

A Phase 1 Open-Label Study to Assess the Tolerability, Safety, and Immunogenicity of Hyaluronidase-Facilitated Subcutaneous Immunoglobulin 20% in Healthy Adults

PURPOSE

Hyaluronidase-facilitated subcutaneous immunoglobulin (fSCIG) 20% will allow reduced infusion volumes and frequency versus existing subcutaneous therapies such as fSCIG 10% and conventional subcutaneous immunoglobulin 20%, respectively. We assessed the tolerability, safety, and immunogenicity of warmed and unwarmed fSCIG 20%.

METHODS

This phase 1, single-dose, open-label, three-arm study enrolled healthy adults aged 19-50 years (inclusive) at a single US center (NCT05059977). Post-screening, participants received a single fSCIG 20% dose comprising recombinant human hyaluronidase and varying doses of in-line warmed or unwarmed immunoglobulin G (IgG) during a 4-day treatment period in a sentinel and sequential dosing design (treatment arm 1, warmed IgG 20% 0.4 g/kg; treatment arm 2, warmed IgG 20% 1.0 g/kg; treatment arm 3, unwarmed IgG 20% 1.0 g/kg). Participants were followed for 12 (± 1) weeks post-infusion. The primary endpoint was tolerability ("tolerable" infusions were not interrupted, stopped, or reduced in rate owing to fSCIG 20%-related treatment-emergent adverse events (TEAEs)). Secondary endpoints included occurrence of TEAEs.

RESULTS

Overall, 24 participants were included, 8 per treatment arm (mean age 39.0 years, 54.2% men). All participants tolerated the infusions. All TEAEs were mild (107 events, in all participants), and all participants experienced fSCIG 20%-related (105 events) and local (102 events) TEAEs. Infusion site erythema and infusion site swelling were most frequently reported. No serious TEAEs occurred, and no participants discontinued the study owing to TEAEs.

CONCLUSION

fSCIG 20% was well-tolerated with a favorable safety profile in healthy adults. Future studies will evaluate fSCIG 20% in primary immunodeficiency diseases. Trial registration number (ClinicalTrials.gov): NCT05059977 (registered 28 September 2021).

Chronic hypogammaglobulinemia after allogeneic stem cell transplantation and their treatment with subcutaneous immunoglobulin in pediatric patients

INTRODUCTION

Hypogammaglobulinemia in the first months after allogeneic hematopoietic stem cell transplantation (HSCT) is common in paediatric patients. During this phase, replacement therapy with human immunoglobulin must be administered parenterally to prevent infections. In some cases, this hypogammaglobulinemia persists over time, which forces further treatment when the patient is usually no longer a carrier of a central line, making them ideal candidates for subcutaneous replacement therapy. There is little published literature describing the use of this method in paediatric patients undergoing HSCT, widely described in replacement treatment in children with primary immunodeficiencies with very good results.

PATIENTS AND METHODS

An observational, descriptive, longitudinal and retrospective study is carried out. During the years 2008-2019, we evaluated all paediatric patients undergoing HSCT in our center with persistent chronic hypogammaglobulinemia (for over a year). The treatment phase with intravenous immunoglobulin (Privigen®) and the first four years of treatment with subcutaneous immunoglobulin (Hizentra®) are evaluated using a questionnaire.

RESULTS

During the years 2008-2019, 175 patients underwent HSCT, 143 (82%) of whom exceeded three months after transplantation. Three (2%) of them had persistent hypogammaglobulinemia. All three share factors described in the literature involved in immune reconstitution. After analysing the questionnaire, it is observed that switching from intravenous to subcutaneous gammaglobulin has involved a great improvement in their quality of life.

CONCLUSIONS

The origin of chronic hypogammaglobulinemia in our patients shows different factors and cannot be attributed to a single cause. Due to the limited number of patients no conclusions can be drawn at the population level. We have been able to observe that replacement treatment with Hizentra 20% has been as effective as the intravenous administration without evidence of an increase in bacterial infections. Furthermore, it has also led to an improvement in quality of life and increased comfort, as the patients themselves have stated.

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.

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.

Correlations Among Subcutaneous Immunoglobulin Dosage, Immunoglobulin G Serum Pre-infusional Levels and Body Mass Index in Primary Antibody Deficiency Patients: A Pooled Analysis from the SHIFT/IBIS Studies

Background and Objective

In recent years, two Italian non-interventional studies evaluated subcutaneous immunoglobulin (SCIG) treatment in patients affected by primary antibody deficiency (PAD). The SHIFT study considered patients who were treated with intravenous immunoglobulin (IVIG) or SCIG 16% (Vivaglobin^®) and then replaced this therapy with weekly treatments of SCIG 20% (Hizentra^®). The IBIS study evaluated patients previously taking a weekly SCIG 20% regimen, who instead began therapy with biweekly SCIG 20% to assess the correlation between the dose of immunoglobulin G (IgG) administered and the body mass index (BMI) of patients, determine if there is a need for dosage adjustments on a BMI basis, and identify the predictors of serum IgG trough levels in our cohort.

Methods

In this study, we analyzed the pooled data of 109 PAD patients enrolled in the SHIFT and IBIS studies. Only prospective phases were considered.

Results

The total monthly SCIG dose showed comparable trends among weight categories, except for underweight patients. When we considered the monthly SCIG dosage per kilogram of body weight, a significant decreasing trend according to BMI was observed. Data on IgG trough levels were available for 88 patients, with a mean IgG serum level of 8.4 ± 1.6 g/L. A stepwise regression model revealed that the mean monthly dosage of SCIG 20% (p = 0.04248) and the mean monthly dosage of IgG per kilogram of body weight were the only two independent predictors associated with IgG trough levels. No association was found between BMI and IgG trough levels.

Conclusions

These findings support the concept that the cumulative monthly dose of SCIG and the dose of SCIG per kilogram of body weight affect IgG trough levels in PAD patients, irrespective of BMI.

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.

Subcutaneous Immunoglobulin Twenty Percent Every Two Weeks in Pediatric Patients with Primary Immunodeficiencies: Subcohort Analysis of the IBIS Study

Background: Subcutaneous immunoglobulin G (SCIG) may be a better option than intravenous immunoglobulin G (IVIG) for patients with primary immunodeficiencies (PID) due to reduced systemic and serious adverse reactions and easier administration. The Infusione Bimensile di Immunoglobuline Sottocute (IBIS) study investigated the effects of Hizentra^®, a 20%-concentrated SCIG, administered biweekly in patients with PID. This subanalysis aimed to evaluate clinical and laboratory outcomes in the IBIS pediatric subcohort. Methods: Thirteen children with PID were observed for 12 months retrospectively (with previous IVIG/SCIG) and prospectively with biweekly Hizentra. Results: Mean ± standard deviation serum IG levels during the retrospective (833.8 ± 175.7 mg/dL) and the prospective (842.0 ± 188.0 mg/dL) phases were comparable; there were also no differences in the number of infections. Conclusions: Biweekly Hizentra is a noninferior option with respect to previous IVIG/SCIG-based treatment.

Immunosuppressive therapy with rituximab in common variable immunodeficiency

Common variable immunodeficiency (CVID) is the most frequent symptomatic primary antibody deficiency in adulthood and is characterized by the marked reduction of IgG and IgA serum levels. Thanks to the successful use of polyvalent immunoglobulin replacement therapy to treat and prevent recurrent infections, non-infectious complications, including autoimmunity, polyclonal lymphoproliferation and malignancies, have progressively become the major cause of morbidity and mortality in CVID patients. The management of these complications is particularly challenging, often requiring multiple lines of immunosuppressive treatments. Over the last 5–10 years, the anti-CD20 monoclonal antibody (i.e., rituximab) has been increasingly used for the treatment of both autoimmune and non-malignant lymphoproliferative manifestations associated with CVID. This review illustrates the evidence on the use of rituximab in CVID. For this purpose, first we discuss the mechanisms proposed for the rituximab mediated B-cell depletion; then, we analyze the literature data regarding the CVID-related complications for which rituximab has been used, focusing on autoimmune cytopenias, granulomatous lymphocytic interstitial lung disease (GLILD) and non-malignant lymphoproliferative syndromes. The cumulative data suggest that in the vast majority of the studies, rituximab has proven to be an effective and relatively safe therapeutic option. However, there are currently no data on the long-term efficacy and side effects of rituximab and other second-line therapeutic options. Further randomized controlled trials are needed to optimize the management strategies of non-infectious complications of CVID.