Efficacy, safety, tolerability and pharmacokinetics of a novel human immune globulin subcutaneous, 20%: a Phase 2/3 study in Europe in patients with primary immunodeficiencies

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.

Towards more tolerable subcutaneous administration: Review of contributing factors for improving combination product design

Subcutaneous (SC) injections can be associated with local pain and discomfort that is subjective and may affect treatment adherence and overall patient experience. With innovations increasingly focused on finding ways to deliver higher doses and volumes (≥2 mL), there is a need to better understand the multiple intertwined factors that influence pain upon SC injection. As a priority for the SC Drug Development & Delivery Consortium, this manuscript provides a comprehensive review of known attributes from published literature that contribute to pain/discomfort upon SC injection from three perspectives: (1) device and delivery factors that cause physical pain, (2) formulation factors that trigger pain responses, and (3) human factors impacting pain perception. Leveraging the Consortium's collective expertise, we provide an assessment of the comparative and interdependent factors likely to impact SC injection pain. In addition, we offer expert insights and future perspectives to fill identified gaps in knowledge to help advance the development of patient-centric and well tolerated high-dose/high-volume SC drug delivery solutions.

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).

An unsupervised learning approach to identify immunoglobulin utilization patterns using electronic health records

BACKGROUND

Managing Canada's immunoglobulin (Ig) product resource allocation is challenging due to increasing demand, high expenditure, and global shortages. Detection of groups with high utilization rates can help with resource planning for Ig products. This study aims to uncover utilization subgroups among the Ig recipients using electronic health records (EHRs).

METHODS

The study included all Ig recipients (intravenous or subcutaneous) in Calgary from 2014 to 2020, and their EHR data, including blood inventory, recipient demographics, and laboratory test results, were analyzed. Patient clusters were derived based on patient characteristics and laboratory test data using K-means clustering. Clusters were interpreted using descriptive analyses and visualization techniques.

RESULTS

Among 4112 recipients, six clusters were identified. Clusters 1 and 2 comprised 408 (9.9%) and 1272 (30.9%) patients, respectively, contributing to 62.2% and 27.1% of total Ig utilization. Cluster 3 included 1253 (30.5%) patients, with 86.4% of infusions administered in an inpatient setting. Cluster 4, comprising 1034 (25.1%) patients, had a median age of 4 years, while clusters 2-6 were adults with median ages of 46-60. Cluster 5 had 62 (1.5%) patients, with 77.3% infusions occurring in emergency departments. Cluster 6 contained 83 (2.0%) patients receiving subcutaneous Ig treatments.

CONCLUSION

The results identified data-driven segmentations of patients with high Ig utilization rates and patients with high risk for short-term inpatient use. Our report is the first on EHR data-driven clustering of Ig utilization patterns. The findings hold the potential to inform demand forecasting and resource allocation decisions during shortages of Ig products.

Real-World Use, Safety, and Patient Experience of 20% Subcutaneous Immunoglobulin for Primary Immunodeficiency Diseases

INTRODUCTION

The CORE study aimed to provide a detailed understanding of real-world immune globulin subcutaneous (human) 20% solution (Ig20Gly) utilization in patients with primary immunodeficiency diseases (PIDs) in Germany and Switzerland.

METHODS

Patients with PIDs receiving a stable dose of any subcutaneous immunoglobulin for ≥ 3 months before enrollment were eligible for this multicenter (n = 5), phase 4, non-interventional, prospective, longitudinal cohort study. Besides baseline demographics and clinical characteristics, Ig20Gly utilization and safety data, and patient-reported outcomes (Life Quality Index/Treatment Satisfaction Questionnaire for Medication) were collected at baseline, 6 and 12 months. Statistical analysis was descriptive.

RESULTS

Overall, 36 patients provided data at baseline [69.4% female; mean age: 41.6 years (7-78 years)]. Totals of 23 and 26 patients attended 6- and 12-month visits, respectively; 16 attended all three visits. One patient withdrew consent before 6-month follow-up. Median maximum infusion rates of Ig20Gly at baseline, 6 months, and 12 months were 26.7, 24.5, and 40.0 mL/h, respectively (10-60 mL/h). Infusion and dosing parameters remained consistent across time points: patients used a median of two infusion sites, primarily the abdomen, and all patients used an infusion pump; all but one infused at home and most self-administered Ig20Gly (80.8-83.3%) at once-weekly intervals (69.2-73.9%). During follow-up, 10 adverse events were reported: none were rated serious, while 2 were considered probably related to Ig20Gly. Total patient-reported outcome scores remained high throughout the study.

CONCLUSION

The CORE study provides real-world evidence of the flexibility, feasibility, safety, and tolerability of Ig20Gly infusions, at mostly weekly intervals, over 1 year in patients with PIDs.

TRIAL REGISTRATION

German Clinical Trials Register, DRKS00014562. Registered April 9, 2018, https://drks.de/search/en/trial/DRKS00014562.

Real-World Evidence of Tolerability of 20% Subcutaneous Immunoglobulin Treatment

PURPOSE

The safety and efficacy of subcutaneous immune globulin 20% (human) solution (Ig20Gly) were demonstrated in clinical trials. However, real-world evidence of the tolerability of self-administered Ig20Gly in elderly patients is lacking. We describe real-world patterns of Ig20Gly usage for 12 months in patients with primary immunodeficiency diseases (PIDD) in the USA.

METHODS

This retrospective chart review of longitudinal data from 2 centers included patients aged ≥ 2 years with PIDD. Ig20Gly administration parameters, tolerability, and usage patterns were assessed at initial and subsequent 6- and 12-month infusions.

RESULTS

Of 47 enrolled patients, 30 (63.8%) received immunoglobulin replacement therapy (IGRT) within 12 months before starting Ig20Gly, and 17 (36.2%) started IGRT de novo. Patients were predominantly White (89.1%), female (85.1%), and elderly (aged > 65 years, 68.1%; median age = 71.0 years). Most adults received at-home treatment during the study, and most self-administered at 6 months (90.0%) and 12 months (88.2%). Across all time points, infusions were administered at a mean rate of 60-90 mL/h/infusion, using a mean of 2 sites per infusion, on a weekly or biweekly frequency. No emergency department visits occurred, and hospital visits were rare (n = 1). Forty-six adverse drug reactions occurred in 36.4% of adults, mostly localized site reactions; none of these or any adverse events led to treatment discontinuation.

CONCLUSION

These findings demonstrate tolerability and successful self-administration of Ig20Gly in PIDD, including elderly patients and patients starting IGRT de novo.

Subcutaneous immunoglobulin 20% (Ig20Gly) treatment regimens in pediatric patients with primary immunodeficiencies - real-world data from the IG TATRY study

BACKGROUND

Subcutaneous administration of immunoglobulins is associated with fewer systemic adverse events and easier infusion compared to intravenous administration. Ig20Gly is a 20% immunoglobulin formulation effective and safe in patients with primary immune deficiency diseases (PIDDs). Real-world data are scarce, therefore our study aimed to examine the real-life treatment regimen and clinical outcomes of Ig20Gly in Polish children with PIDDs.

RESEARCHDESIGN

We retrospectively analyzed the medical documentation of 75 pediatric patients aged 0-17 years (mean 9.9) who received Ig20Gly (Cuvitru®; Baxalta US, Inc.; part of Takeda, MA, U.S.A.).

RESULTS

The median exposure to treatment of the study population was 22.3 months. At the end of the study, 59 (78.7%) were still on Ig20Gly. The median monthly dose was 0.40 g/kg. The median treatment interval was 7.7 days. Most patients (96%) used one infusion site. The median infusion rate increased with patient age. The median IgG level in the study population, 8.0 g/L, was stable. There was one case of serious bacterial infection.

CONCLUSION

This is the largest, long-term real-world study to date on the treatment patterns of Ig20Gly in pediatric patients with PIDDs. The results of this study support the feasibility and tolerability of Ig20Gly usage in PIDD patients across the pediatric age spectrum.

TRIAL REGISTRATION

The trial is registered at ClinicalTrials.gov (NCT04636502).

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.

Cytomegalovirus Pneumonia in a Patient with X-Linked Agammaglobulinemia: A Case Report

X-linked agammaglobulinemia (XLA) is a hereditary immune disorder that predisposes patients to frequent and severe bacterial infections caused by encapsulated bacteria (such as Streptococcus pneumoniae, Staphylococcus aureus, and Haemophilus influenzae). Otitis media, sinusitis, and pneumonia are common complications of XLA that require prompt diagnosis and treatment. Cytomegaloviruses (CMV) cause widespread and severe infections in immunocompromised individuals, affecting the respiratory tract, and consequently, leading to pneumonia, which is associated with a high mortality rate. However, CMV-induced pneumonia is rarely reported in patients with XLA. This case study details a 37-year-old male patient with XLA presenting with fever, productive cough, and dyspnea. The patient was diagnosed with CMV pneumonia and recovered after treatment. To the best of our knowledge, this is the first reported case of CMV pneumonia in a patient with XLA in Taiwan. This case study emphasizes that CMV pneumonia in patients with XLA is a treatable condition if diagnosed promptly, and that a shorter duration of treatment with the antiviral agent, in combination with immunoglobulin replacement therapy, can resolve symptoms.

A clinician's guide for administration of high-concentration and facilitated subcutaneous immunoglobulin replacement therapy in patients with primary immunodeficiency diseases

Immunoglobulin replacement therapy is the standard-of-care treatment for patients with primary immunodeficiency diseases who have impaired antibody production and function. Clinicians and patients may consider intravenous immunoglobulin (IVIG) or subcutaneous immunoglobulin (SCIG) options, and each route may offer different benefits for the individual. IVIG requires fewer infusion sites and less frequent infusions than some formulations of SCIG. However, SCIG does not require venous access, is associated with fewer systemic adverse infusion reactions than IVIG, and can independently be self-administered at home. Importantly, tailoring treatment experiences to the needs of the individual may improve treatment adherence and quality of life for patients with primary immunodeficiency diseases who often rely on long-term or lifelong treatment. This review aims to educate United States (US) healthcare providers on the administration process of SCIG, with a focus on more concentrated formulations of SCIG and facilitated SCIG. It provides practical guidance on initiating, optimizing, and monitoring SCIG therapy. The advantages and disadvantages of the different treatment options are also presented for discussion between the patient and clinician.

Transitioning subcutaneous immunoglobulin 20% therapies in patients with primary and secondary immunodeficiencies: Canadian real-world study

Background

Real-world data on transitioning to Immune Globulin Subcutaneous (Human) 20% solution (Ig20Gly) are limited. This study aimed to assess infusion parameters and experience of patients with primary (PID) or secondary immunodeficiencies (SID) transitioning to Ig20Gly in clinical practice in Canada.

Methods

Patients with PID or SID who received subcutaneous immunoglobulin (SCIG) for ≥ 3 months before transitioning to Ig20Gly were eligible for this multicenter (n = 6), phase 4, non-interventional, prospective, single-arm study. Ig20Gly infusion parameters, dosing, and adverse events were collected from patient medical records at Ig20Gly initiation and 3, 6, and 12 months post-initiation. Patient satisfaction and quality of life were assessed 12 months post-initiation using validated questionnaires.

Results

The study included 125 patients (PID, n = 60; SID, n = 64; PID + SID, n = 1). Median volume per infusion was 30.0 ml at initiation, and 40.0 ml at 6 and 12 months post-initiation. Most patients administered Ig20Gly weekly and used two infusion sites (primarily abdomen). At each time point, median infusion duration was ≤ 1 h. At 12 months, 61% of infusions were administered via a pump and 39% manually. Headache and infusion-site reactions were the most reported adverse events of interest. Patients expressed overall satisfaction with Ig20Gly at 12 months post-initiation, with all respondents indicating they would like to continue Ig20Gly.

Conclusions

This study provides a detailed description of Ig20Gly infusion parameters, tolerability, and quality of life in clinical practice among patients with PID or SID switching to Ig20Gly from another SCIG and confirms the feasibility of infusing Ig20Gly via pump or manual administration.

Trial registration NCT03716700, Registered 31 August 2018, https://clinicaltrials.gov/ct2/show/NCT03716700

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-022-00709-8.

A Multi‑Center, Open‑Label, Single‑Arm Trial to Evaluate the Efficacy, Pharmacokinetics, and Safety and Tolerability of IGSC 20% in Subjects with Primary Immunodeficiency

Purpose

The purpose of this phase 3 study was to evaluate the efficacy, pharmacokinetics (PK), and safety of Immune Globulin Subcutaneous (Human), 20% Caprylate/Chromatography Purified (IGSC 20%) in patients with primary immunodeficiency (PI).

Methods

Immunoglobulin treatment-experienced subjects with PI received 52 weeks of IGSC 20% given weekly at the same dose as the subject’s previous IgG regimen (DAF 1:1); the minimum dose was 100 mg/kg/week. The primary endpoint was serious bacterial infections (SBIs [null vs alternative hypothesis: SBI rate per person per year ≥ 1 vs < 1]). IgG subclasses and specific pathogen antibody levels were also measured.

Results

Sixty-one subjects (19 children [≤ 12 years], 10 adolescents [> 12–16 years], and 32 adults) were enrolled. The rate of SBIs per person per year was 0.017. The 1-sided 99% upper confidence limit was 0.036 (< 1), and the null hypothesis was rejected. The rate of hospitalization due to infection per person per year was 0.017 (2-sided 95% confidence interval: 0.008–0.033) overall. The mean trough total IgG concentrations were comparable to the previous IgG replacement regimen. The average of the individual mean trough ratios (IGSC 20%:previous regimen) was 1.078 (range: 0.83–1.54). The average steady-state mean trough IgG concentrations were 947.64 and 891.37 mg/dL, respectively. Seven subjects had serious treatment-emergent adverse events (TEAEs); none was drug-related. The rate of all TEAEs, including local infusion site reactions, during 3045 IGSC 20% infusions was 0.135. Most TEAEs were mild or moderate.

Conclusions

IGSC 20% demonstrated efficacy and good safety and tolerability in subjects with PI.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10875-021-01181-6.

Population pharmacokinetic simulation of varied Immune Globulin Subcutaneous (Human), 20% solution (Ig20Gly) loading and maintenance dosing regimens in immunoglobulin-naïve patients with primary immunodeficiency diseases

BACKGROUND

The pharmacokinetics of Ig20Gly, a 20% subcutaneous immunoglobulin (IG) therapy, is well characterized in IG-experienced patients with primary immunodeficiency diseases (PID). Data from IG-naïve patients are limited.

OBJECTIVE

Simulate serum total immunoglobulin G (IgG) pharmacokinetic profiles in IG-naïve patients with PID for different Ig20Gly initiation and maintenance dosing regimens.

METHODS

A population pharmacokinetic model developed with data from pivotal phase 2/3 trials of weekly Ig20Gly in PID (NCT01412385, NCT01218438) was used to simulate pharmacokinetic profiles of IgG in various scenarios with 400- or 800-mg/kg total loading doses (administered as split doses over 1-2 weeks) and corresponding 100- or 200-mg/kg weekly maintenance doses, respectively. Endogenous baseline IgG levels (1.5, 2.0, 4.0, 6.0 g/L) were evaluated for each scenario; time to putative therapeutic target IgG trough level (7 g/L) was determined.

RESULTS

Serum IgG levels reached steady-state by approximately Week 12 for all scenarios and baseline endogenous IgG levels. Time to target trough level generally occurred sooner with 1-week versus 2-week loading schemes. Endogenous baseline IgG levels <4 g/L required a 1-week 800-mg/kg total loading dose to achieve target levels within 2 weeks. Both maintenance regimens sustained serum IgG above target level.

CONCLUSIONS

Simulations indicated IG-naïve patients with PID can achieve protective serum IgG levels within 1-3 weeks using appropriate Ig20Gly loading regimens. Patients with low endogenous IgG may benefit most from an 800-mg/kg/month loading dose. 400- or 800-mg/kg/month Ig20Gly maintenance regimens appeared adequate to maintain stable IgG levels. Serum IgG monitoring and clinical status can guide dosing parameters.

Infusion parameters of 20% subcutaneous immunoglobulin for primary immunodeficiency diseases among patient support program participants

BACKGROUND

The safety and efficacy of subcutaneous immune globulin 20% (human) solution (Cuvitru; Ig20Gly) for primary immunodeficiency disease (PID) have been demonstrated in 2 pivotal trials.

OBJECTIVE

To describe patient characteristics and infusion parameters of patients with PID initiating Ig20Gly outside of a clinical trial setting.

METHODS

This retrospective, observational study analyzed records of patients participating in the HelloCuvitru program, a patient support program in the United States providing Ig20Gly free of charge for the first 4 infusions to patients aged 2 years or older who had PID and no previous experience of Ig20Gly. Data were collected retrospectively from patient records and during nurse visits.

RESULTS

A total of 817 patients (88% of 931 enrolled) completed 4 infusions. At the fourth Ig20Gly infusion, the median (interquartile range) dose was 0.55 (0.46-0.69) g/kg/mo, infusion rate/site was 40 (30.0-50.0) mL, and infusion rate per site was 47 (42.5-53.3) mL/h/site. By the fourth infusion, most patients (58%) received Ig20Gly at 2 infusion sites every 7 (30%) or 14 (25%) days. Median prescribed Ig20Gly dose per month was similar across age groups; median infusion volume per site increased with age. Most patients younger than 18 years received infusions every 14 days; patients aged 18 years or older were more likely to receive infusions weekly. Infusion parameters were similar regardless of whether patients received previous immunoglobulin subcutaneously or intravenously.

CONCLUSION

In this large, real-world population of patients with PID, most Ig20Gly infusions were administered for less than 1 hour and required fewer than 2 infusion sites, consistent with the pivotal trials. Infusion rate per site was similar regardless of age, previous immunoglobulin treatment, or infusion frequency.

Steady-State Serum IgG Trough Levels Are Adequate for Pharmacokinetic Assessment in Patients with Immunodeficiencies Receiving Subcutaneous Immune Globulin

Patients with primary immunodeficiency diseases often require lifelong immunoglobulin (IG) therapy. Most clinical trials investigating IG therapies characterize serum immunoglobulin G (IgG) pharmacokinetic (PK) profiles by serially assessing serum IgG levels. This retrospective analysis evaluated whether steady-state serum IgG trough level measurement alone is adequate for PK assessment. Based on individual patient serum IgG trough levels from two pivotal trials (phase 2/3 European [NCT01412385] and North American [NCT01218438]) of weekly 20% subcutaneous IG (SCIG; Cuvitru, Ig20Gly), trough level-predicted IgG AUC (AUC_τ,tp) were calculated and compared with the reported AUC calculated from serum IgG concentration-time profiles (AUC_τ). In both studies, mean AUC_τ,tp values for Ig20Gly were essentially equivalent to AUC_τ with point estimates of geometric mean ratio (GMR) of AUC_τ,tp/AUC_τ near 1.0 and 90% CIs within 0.80-1.25. In contrast, for IVIG, 10%, mean AUC_τ,tp values were lower than AUC_τ by >20%, (GMR [90% CI]: 0.74 [0.70-0.78] and 0.77 [0.73-0.81] for the two studies, respectively). Mean AUC_τ,tp values calculated for 4 other SCIG products (based on mean IgG trough levels reported in the literature/labels) were also essentially equivalent to the reported AUC_τ (differences <10% for all except HyQvia, a facilitated SCIG product), while differences for IVIG products were >20%. In conclusion, steady-state serum IgG levels following weekly SCIG remain stable, allowing for reliable prediction of AUC over the dosing interval using trough IgG levels. These findings indicate that measuring steady-state serum IgG trough levels alone may be adequate for PK assessment of weekly SCIG.

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.

Safety and Tolerability of Subcutaneous IgPro20 at High Infusion Parameters in Patients with Primary Immunodeficiency: Findings from the Pump-Assisted Administration Cohorts of the HILO Study

PURPOSE

To evaluate the safety and tolerability of subcutaneous IgPro20 (Hizentra^®, CSL Behring, King of Prussia, PA, USA) administered at high infusion parameters (> 25 mL and > 25 mL/h per injection site) in patients with primary immunodeficiency.

METHODS

The Hizentra^® Label Optimization (HILO) study was an open-label, parallel-arm, non-randomized study (NCT03033745) of IgPro20 using a forced upward titration design for infusion parameters. Patients experienced with pump-assisted IgPro20 infusions received weekly IgPro20 infusions at a stable dose in the Pump-Assisted Volume Cohort (N = 15; 25-50 mL per injection site) and in the Pump-Assisted Flow Rate Cohort (N = 18; 25-100 mL/h per injection site). Responder rates (percentage of patients who successfully completed ≥ 75% of planned infusions), safety outcomes, and serum immunoglobulin G (IgG) trough levels were evaluated.

RESULTS

Responder rates were 86.7% (13/15, 25 mL) and 73.3% (11/15, 40 and 50 mL) in the Volume Cohort, and 77.8% (14/18, 25 and 50 mL/h), 66.7% (12/18, 75 mL/h), and 61.1% (11/18, 100 mL/h) in the Flow Rate Cohort. Infusion compliance was ≥ 90% in all patients in the Volume Cohort and in 83.3% of patients in the Flow Rate Cohort. The number of injection sites (Volume Cohort) and the infusion duration (Flow Rate Cohort) decreased with increasing infusion parameters. The rate of treatment-emergent adverse events per infusion was low (0.138 [Volume Cohort] and 0.216 [Flow Rate Cohort]). Serum IgG levels remained stable during the study.

CONCLUSION

Pump-assisted IgPro20 infusions are feasible at 50 mL and 100 mL/h per injection site in treatment-experienced patients, which may result in fewer injection sites and shorter infusion times.

TRIAL REGISTRATION

NCT03033745 ; registered January 27, 2017.

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.

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.

A Systematic Review and Meta-regression Analysis on the Impact of Increasing IgG Trough Level on Infection Rates in Primary Immunodeficiency Patients on Intravenous IgG Therapy

PURPOSE

We conducted a systematic review and meta-regression analysis to evaluate the impact of increasing immunoglobulin G (IgG) trough levels on the clinical outcomes in patients with PID receiving intravenous immunoglobulin G (IVIG) treatment.

METHODS

Systematic search was conducted in PubMed and Cochrane. Other relevant articles were searched by reviewing the references of the reviewed article. All clinical trials with documented IgG trough levels and clinical outcome of interest in patients receiving IVIG treatment were eligible to be included in this review. Meta-regression analysis was conducted using Comprehensive Meta-analysis Software. Additional sensitivity analyses were undertaken to evaluate the robustness of the overall results.

RESULTS

Twenty-eight clinical studies with 1218 patients reported from year 2001 to 2018 were included. The mean IVIG dose used ranges from 387 to 560 mg/kg every 3 to 4 weekly, and mean IgG trough obtained ranges from 660 to 1280 mg/dL. Random-effects meta-regression slope shows that IgG trough level increases significantly by 73 mg/dL with every increase of 100 mg/kg dose of IVIG (p < 0.05). Overall infection rates reduced significantly by 13% with every increment of 100 mg/dL of IgG trough up to 960 mg/dL (p < 0.05).

CONCLUSION

This meta-analysis concludes that titrating the IgG trough levels up to 960 mg/dL progressively reduces the rate of infections, and there is less additional benefit beyond that. Further studies to validate this result are required before it can be used in clinical practice.

Patient experience with subcutaneous immunoglobulin 20%, Ig20Gly, for primary immunodeficiency diseases: a prespecified post hoc analysis of combined data from 2 pivotal trials

BACKGROUND

Often, patients with primary immunodeficiency diseases (PID), which are marked by the absence or loss of functional antibodies, require lifelong treatment with immunoglobulin (IG) replacement therapy administered either intravenously (intravenous immunoglobulin [IVIG]) or subcutaneously (subcutaneous immunoglobulin [SCIG]). In patients with PID, the 20% SCIG product, Ig20Gly, was shown to be efficacious and well tolerated in 2 phase 2/3 trials conducted in North America and Europe. This analysis evaluated patient satisfaction with Ig20Gly therapy and treatment preferences.

METHODS

This prespecified post hoc analysis showed combined data from 2 Ig20Gly pivotal trials. Treatment satisfaction was assessed in the pre-Ig20Gly period and after ≥11 months of Ig20Gly treatment using the Life Quality Index (LQI; both studies) and the Treatment Satisfaction Questionnaire for Medication-9 (TSQM-9; North American study only). Treatment preference was assessed using a survey at the end of the European study. Median within-patient differences in LQI and TSQM-9 scores between the pre-Ig20Gly period and the end of the Ig20Gly treatment period were assessed using the Wilcoxon signed-rank test.

RESULTS

A total of 113 patients (n = 68 [North American]; n = 45 [Europe]) with PID were included in the analysis. In the combined LQI analysis (n = 110), significant improvements were observed in the treatment interference (median ∆: + 2.8; P = 0.006) and therapy setting (median ∆: + 5.6; P < 0.0001) domains, and in the item-level scores for convenience (median ∆: + 1.0; P < 0.0001) and interference with work/school (median ∆: + 1.0; P = 0.0001) categories. In the subgroup analyses, significant improvements in the treatment interference and therapy setting domains and the convenience and interference with work/school items were observed for those who had previously received treatment outside the home, those who had previously received IVIG, and those in the North American study. Significant improvements were observed in the TSQM-9 treatment convenience domain (median ∆: + 11.1; P < 0.0001) and selected item-level scores in the North American study. In the European study, most (88.9%) patients preferred to continue Ig20Gly versus other IG treatments.

CONCLUSIONS

After ≥11 months of taking Ig20Gly, patients reported high levels of treatment satisfaction, convenience, and preference for Ig20Gly, with consistent results across studies and use of multiple patient-reported outcome measures.

Efficacy and safety of octanorm (cutaquig®) in adults with primary immunodeficiencies with predominant antibody deficiency: a prospective, open-label study

Aim: To evaluate efficacy and safety of octanorm (16.5% subcutaneous immunoglobulin) in adult patients with primary immunodeficiencies. Patients & methods: Primary immunodeficiencies patients (18-70 years) previously treated with intravenous immunoglobulin were included in this Phase III study. Octanorm was administered subcutaneously once weekly over 8 months. End points included infections, adverse events and quality of life. Results: 25 patients (mean age 35.2 years, female 60.0%) were recruited, 24 completed the study. Mean dose of octanorm was 0.11 g/kg/week. No serious bacterial infections occurred. Three patients (12.0%) had an adverse event (mild) assessed as related to octanorm. Both the mental and physical summary 36-item Short Form Health Survey scores were improved. Conclusion: Octanorm is effective, safe and improves quality of life. Clinical Trial registration number: NCT03988426.

Impact of IVIG vs. SCIG on IgG trough level and infection incidence in primary immunodeficiency diseases: A systematic review and meta-analysis of clinical studies

Background

Monthly intravenous immunoglobulin (IVIG) and weekly subcutaneous immunoglobulin (SCIG) have been regarded as therapeutically equivalent treatments for primary immunodeficiency diseases (PIDD). Immunoglobulin G (IgG) trough level is used as a monitoring measure for infection prevention.

Objective

A systematic review and meta-analysis were performed to elucidate the relationship between IgG dosing, trough IgG levels with overall infection incidence in patients with PIDD receiving IVIG and SCIG therapy.

Methods

Medline, EMBASE, Cochrane, Central, and Scopus were searched for studies published from Jan 2010-June 2018, fulfilling the inclusion criteria. DerSimonian and Laird random-effects method were used to pool the difference of IgG trough levels. Random-effect meta-regression was used to evaluate infection incidence per 100 mg/dl IgG trough increase though IVIG and SCIG.

Results

Out of 24 observational studies included, 11 compared IgG trough levels among SCIG and IVIG (mean difference: 73.4 mg/dl, 95% CI: 31.67-119.19 mg/dl, I2 = 45%, p = 0.05), favoring weekly SCIG. For every 100 mg/dl increase in the trough, a linear trend of decreased incidence rates of infection was identified in SCIG patients (p = 0.03), but no similar trend was identified in trough levels vs. infection rates for patients receiving IVIG (p = 0.67).

Conclusion

In our study, weekly SCIG attained a higher trough level in comparison to monthly IVIG. Higher SCIG troughs were associated with lower infection rates, while IVIG troughs demonstrated no relationship.

Safety and tolerability of subcutaneous immunoglobulin 20% in primary immunodeficiency diseases from two continents

Aim: This pooled analysis evaluated the safety and tolerability of the subcutaneous immunoglobulin 20% product, Ig20Gly, in primary immunodeficiency diseases using data from two Phase II/III studies conducted in North America and Europe. Patients & materials/methods: Patients received Ig20Gly (volumes, ≤60 ml/site; rates, ≤60 ml/h/site). Adverse events (AEs), tolerability and infusion parameters were assessed. Results: Patients (2-83 years; N = 122) received 6676 Ig20Gly infusions. No causally related serious or severe AEs were reported. Thirty-five patients (28.7%) reported 232 causally related local AEs. Twenty-seven patients (22.1%) reported 165 causally related systemic AEs. There was no association between the infusion volume or rate and causally related local AEs. Conclusion: Ig20Gly was well tolerated in a broad population of patients with primary immunodeficiency diseases.

Tolerability of Ig20Gly during onboarding in patients with primary immunodeficiency diseases

BACKGROUND

The subcutaneous immune globulin (SCIG) 20% product, Ig20Gly, was shown to be efficacious and well tolerated in 2 phase 2/3 North American and European studies at infusion volumes up to 60 mL/site and rates up to 60 mL/h/site in patients with primary immunodeficiency diseases.

OBJECTIVE

To assess patient experience after switching to Ig20Gly with fast infusion rates and large infusion volumes/site in the North American study.

METHODS

In this analysis of the open-label phase 2/3 study in which patients aged ≥2 years received weekly Ig20Gly infusions for up to approximately 1.3 years, tolerability and infusion parameters were assessed throughout the study for all patients and by prestudy treatment regimen (intravenous [IV] switchers or SC switchers).

RESULTS

Overall, 61% of patients reached the infusion rate of ≥60 mL/h/site and continued at this rate for 1 or more subsequent infusions; the median infusion number when patients first reached ≥60 mL/h/site was 3. No association was found between higher infusion volumes or rates and increased incidences of local and systemic adverse events (AEs) in the total population and patients younger than 16 years. Infusion parameters and tolerability were generally comparable regardless of the route of prestudy treatment (IV or SC switchers); however, IV switchers experienced lower rates of local AEs than SC switchers and had a slightly higher median infusion volume per site and longer infusion duration vs SC switchers.

CONCLUSION

High Ig20Gly infusion rates of at least 60 mL/h/site and volumes ≥60 mL/site were well tolerated during onboarding and throughout treatment, regardless of prestudy treatment.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT01218438.

Clinical Efficacy, Safety and Tolerability of a New Subcutaneous Immunoglobulin 16.5% (Octanorm [Cutaquig®]) in the Treatment of Patients With Primary Immunodeficiencies

Introduction: Subcutaneously administered immunoglobulin (SCIG) is increasingly used to treat patients with primary immunodeficiencies (PIDs). Octanorm (marketed as cutaquig® in USA and Canada) is a new 16.5% solution of human SCIG, manufactured by a process based on that of the intravenous preparation (IVIG) octagam®. Objectives: To investigate the efficacy, safety and tolerability of octanorm in a prospective, open-label, single-arm phase 3 study involving adult and pediatric patients with PIDs (NCT01888484; clinicaltrials.gov/ct2/show/NCT01888484). Methods: Patients who were previously treated with IVIG received a total of 64 weekly SCIG infusions, including 12 weekly infusions during the wash-in/wash-out period, followed by 52 weekly infusions during the evaluation period. Results: A total of 61 patients aged 2-73 years received 3,497 infusions of octanorm. The mean dose per patient was 0.175 g/kg/infusion. The mean calculated dose conversion factor from the patients' previous IVIG dose for octanorm was 1.37. No serious bacterial infections developed during the study. The rate of other infections per person-year during the primary observation period was 3.43 (upper 95% CI 4.57). All but one non-bacterial infection were mild or moderate in intensity. IgG trough levels were constant during the course of the study. Eleven patients (18.0%) experienced 14 mild or moderate systemic adverse events (AEs) related to octanorm. The rate of related AEs per infusion was 0.004. In 76.7% of infusions, no infusion site reactions were observed and only two (0.3%) reactions were deemed severe. The incidence of site reactions decreased with successive infusions. Conclusion: The new 16.5% SCIG octanorm was shown to be efficacious in preventing infections in PIDs, and was well tolerated.

Tolerability of subcutaneous immunoglobulin 20%, Ig20Gly, in pediatric patients with primary immunodeficiencies

AIM

To assess Ig20Gly tolerability in pediatric patients with primary immunodeficiencies.

PATIENTS & METHODS

Infusion parameters and tolerability were analyzed in pediatric patients (aged 2-5 years [n = 6], 6-11 years [n = 22] and 12-17 years [n = 22]) receiving Ig20Gly in two Phase II/III trials.

RESULTS

Of 2624 Ig20Gly infusions, >99% did not require any rate reduction, interruption or discontinuation due to adverse events (AEs). Median maximum infusion rates and volumes/site were higher in patients 12-17 years of age (30 ml/h/site; 30 ml/site) versus 6-11 years (20 ml/h/site; 15 ml/site) and 2-5 years (18 ml/h/site; 14 ml/site). Rates of causally related systemic and local AEs (0.009 and 0.063 AEs/infusion) were low.

CONCLUSION

Ig20Gly infused at relatively high rates and volumes was well tolerated in children.

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

Many patients with primary immunodeficiency (PID) require immunoglobulin G (IgG) replacement therapy, delivered as intravenous IgG (IVIG) or subcutaneous IgG (SCIG). We aim to identify trends in efficacy and safety that would not be evident in individual studies of small patient numbers. Seven open-label, Phase 3, prospective, multicenter studies of the efficacy and safety of Hizentra® (a SCIG), conducted in Japan, Europe, and the US were summarized. Overall, 125 unique patients received 15,013 weekly infusions during a total observation period of 250.9 patient-years. Mean weekly doses of Hizentra® were 83.22–221.3 mg/kg body weight; infusion rates per patient (total body rate) were 25.2–49.3 mL/h across studies. The rates of infections and serious bacterial infections were 3.10 and 0.03 events per patient/year, respectively. Annualized rates of days hospitalized due to infection, out of work/school, and prophylactic antibiotic use were 0.95, 5.14, and 36.78 per patient, respectively. For the equivalent monthly dose, weekly Hizentra® SCIG administration resulted in expectedly-increased serum IgG trough levels in patients switching from IVIG, and maintained levels in patients switching from previous SCIG. Adverse events (AEs) totaled 5039 (events/infusion 0.094–0.773), almost all of which were mild/moderate. Three thousand one hundred ninety-seven were considered treatment-related, the most common of which were injection site reactions (2919 events; 0.001–0.592 AEs per infusion). Systemic AEs were very uncommon. The results from these seven studies indicate that Hizentra® therapy was both efficacious and well tolerated during long-term treatment. This is particularly important in patients with PID, who may require lifelong IgG replacement therapy.

Timing of infections in patients with primary immunodeficiencies treated with intravenous immunoglobulin (IVIg)

Purpose

Patients with common variable immune deficiency and X-linked agammaglobulinemia are unable to produce their own antibodies thus leading to a higher incidence of recurrent infections, particularly those involving the sinuses and lungs. Treatment with intravenous immunoglobulin therapy aims to reduce the incidence of infections; however, as serum IgG approaches its trough during the third and fourth week after infusion, we hypothesized that the rate of infection would be higher during this time period.

Methods

Patients with a diagnosis of either common variable immunodeficiency (CVID) or X-linked agammaglobulinemia (XLA) treated with intravenous immunoglobulin (IVIg) were analyzed in a prospective cohort study. Data was obtained as to the timing of symptom onset post infusion, the type of infection, as well as timing of the initiation of antibiotics. Descriptive analyses were conducted to explore the patterns of the data at each month and then over the course of the study year.

Results

Twenty-three patients with a diagnosis of either CVID (n = 22), or XLA (n = 1) were enrolled with a mean follow duration of 11.3 months. The mean number of days to infection after IVIg infusion, the primary endpoint, was 17.0 days with the most common infections reported as sinusitis and upper respiratory tract infections. There was no statistically significant difference (p = 0.70) in the rates of infection when considering the weeks post-infusion.

Conclusions

We believe that this pilot study is the first reported prospective study to examine the timing of infections after IVIg infusion in individuals with CVID and XLA. Further multi-centered research with a larger sample size is required into the comparison of infection rates in primary immunodeficiency patients treated with IVIg versus subcutaneous immunoglobulin therapy, where serum IgG levels remain at steady state.

An evaluation of the budget impact of a new 20% subcutaneous immunoglobulin (Ig20Gly) for the management of primary immunodeficiency diseases in Switzerland

Introduction

While most individual primary immunodeficiency diseases (PID) are rare, the collective prevalence of PID results in a substantial economic and clinical burden. The aim of this study was to evaluate the budgetary implications of Ig20Gly (Immune Globulin Subcutaneous [human] 20% solution; CUVITRU^®, Baxalta US Inc, now part of Shire Plc, Westlake Village, CA, USA) as a treatment for PID relative to intravenous immunoglobulin (IVIG) and other subcutaneous immunoglobulin (SCIG) formulations in the Swiss health care setting.

Materials and methods

A budget impact model was developed in Microsoft Excel to capture the estimated prevalence of PID in Switzerland, the proportion of patients treated in different health care settings, and the costs of administering SCIG and IVIG in each setting. Unit costs were based on a recent cost-minimization analysis of SCIG in Lausanne, and drug costs were taken from the Spezialitätenliste. All costs were reported in 2016 Swiss Francs (CHF), and future costs were not discounted.

Results

The total cost of treating PID in Switzerland was estimated to be CHF 11.16 m over 3 years, comprising CHF 9.28 m of drug costs and CHF 1.87 m of ancillary costs, including health care professional time and other administration costs, such as pumps and needle sets. The analysis showed that using Ig20Gly in place of other SCIG formulations would be cost neutral, while using Ig20Gly in place of IVIG would result in savings of 4.0%.

Conclusion

Ig20Gly would be cost neutral relative to existing SCIG products and would result in cost savings relative to IVIG in patients with PID in Switzerland, even with modest uptake.

Passive blood anaphylaxis: subcutaneous immunoglobulins are a cause of ongoing passive anaphylactic reaction

Background

Allergic, especially anaphylactic, reactions during immunoglobulin replacement therapy are rare, but their pathophysiology and classification remain ambiguous. Recent findings show positive results of skin tests with commercially available immunoglobulins, but target antigens and responsible compounds of the tested immunoglobulins have not been strictly identified.

Case description and findings

Four adult patients with recently diagnosed common variable immunodeficiency qualified for standard subcutaneous immunoglobulin replacement therapy regimen. They had no history of receiving immunoglobulins, blood or blood product transfusions. Edema, confluent wheals and erythema were observed at the site of subcutaneous immunoglobulin infusion: typical early and late phase reaction. A transient increase in various passively transferred IgG and IgE antibodies was responsible for misleading positive outcome of the serological testing for active humoral response such as type I allergy, anti-Rh, isohemagglutinins and rheumatoid factor (RF). Although the clinical presentation was very unusual and severe, the retrospective analysis showed no isohemagglutinins, RF and IgE in the patients’ serum before but it was positive after the infusion (median IgE = 18 IU/ml, RF = 8 IU/ml). Type I allergic reaction (laryngeal edema, rhinoconjuctivitis) came out at +14 days of replacement therapy when the patient visited countryside. In the second patient anaphylactic reaction was observed 5 days after ScIg administration, and only when the patient consumed peanuts. Therefore, IgE concentration was measured retrospectively in a series of commercial preparations used in the initial subcutaneous immunoglobulin replacement therapy that caused the adverse event (AE) and it was determined between 138 and 232 IU/ml (kU/l), i.e. 690–2100 IU per g of protein. Specific IgE was within a wide range from 198 (mix of food) to 2809 kUA/l (mix of grass) but many of the tested allergen-specific IgE were class 2 or 3 (i.e. 0.71–17.5 kUA/l).

Conclusions

The case resembles passive cutaneous anaphylaxis and Prausnitz–Küstner reaction but clinical significance of the classical phenomena has not yet been described. This observation indicates that anaphylactic reactions during immunoglobulin replacement therapy may result from IgE or pathological IgG content. Such IgE presence was sporadically reported (34.5–105 IU/ml, i.e. 862.5–1450 IU/g of protein) in intravenous immunoglobulins that are used and monitored by healthcare professionals. In clinical practice the definition of adverse events is inadequate since individual batches of immunoglobulins come with different specificity therefore, they should be classified as transfusion products (not bioequivalents). Such new approach implies establishing (1) new control methods and strategies to ensure introduction of the safety regulations for subcutaneous home self-administration of immunoglobulins as well as (2) guidelines for the prevention of anaphylaxis in patients receiving immunoglobulins (for example peanut).

Recombinant human hyaluronidase-facilitated subcutaneous immunoglobulin infusion in primary immunodeficiency diseases

Most primary immunodeficiency diseases (PIDDs) resulting in antibody deficiency require intravenous or subcutaneous immunoglobulin G (SCIG) replacement therapy. The flow and distribution of SCIG to the vasculature is impeded by the glycosaminoglycan hyaluronan in the extracellular matrix, which limits the infusion rate and volume per site, necessitating frequent infusions and multiple infusion sites. Hyaluronidase depolymerizes hyaluronan and is a spreading factor for injectable biologics. Recombinant human hyaluronidase (rHuPH20) increases SCIG absorption and dispersion. In patients with PIDD, SCIG facilitated with rHuPH20 (IGHy) has been shown to prevent infections, be well-tolerated and reduce infusion frequency and number of infusion sites as compared with conventional SCIG. This article reviews IGHy clinical studies and real-world practice data in patients with PIDD.