Comparison of the efficacy of IGIV-C, 10% (caprylate/chromatography) and IGIV-SD, 10% as replacement therapy in primary immune deficiency. A randomized double-blind trial

Comparison of Intravenous Immunoglobulin Formulations: Product Formulary, and Cost Considerations

Purpose

A review of the different formulations of intravenous immunoglobulin (IVIG) replacement therapy for primary immunodeficiency and other severe diseases, focusing on the comparative efficacy, safety, and tolerability of these formulations. This review discusses the manufacturing processes, physicochemical properties, and other attributes of IVIG therapy that affect its clinical utility.

Summary

IVIG therapy is a preferred treatment for patients with certain types of primary immunodeficiency, neuroimmunologic, and autoimmune hematologic disorders, as well as for immunomodulation in bone marrow and some solid organ transplants. The IVIG products available in the United States include lyophilized, 5% liquid, and 10% ready-to-use liquid formulations. Differences among these formulations in their manufacturing processes, excipients, pH, and physicochemical properties may be reflected as differences in clinical efficacy, safety, and tolerability. For example, compared with lyophilized and 5% liquid IVIG formulations, 10% ready-to-use IVIG liquid formulations may be associated with better tolerability because of lower IgA concentrations, optimal pH, use of glycine or proline stabilizers, low sodium content, and less osmolality. Liquid formulations (both 5% and 10%) may provide greater convenience than lyophilized formulations for both patients and health care providers, because they do not require further dilution before administration and have shorter infusion times.

Conclusion

Before selecting an IVIG product for a hospital formulary, pharmacists should be knowledgeable about the product's concentration to ensure delivery of the proper dosage, the staff training needed for proper administration, the potential benefits and problems of brand substitution, the safety and efficacy of each formulation, the hospital's policies on off-label use of IVIG, and the impact of reimbursement.

Bringing immunoglobulin knowledge up to date: how should we treat today?

Immunoglobulin (Ig) therapy is constantly evolving. Advances in the basic and clinical science of immunoglobulins have provided new perspectives in using polyclonal IgG to treat patients with primary immunodeficiencies. Recent meta-analyses of patient data and outcomes, optimization of IgG administration and better understanding of the IgG receptor variability and clinical effect are new concepts which practising immunologists can use in tailoring their approach to treating patients with primary immunodeficiencies. This manuscript presents the proceedings of a satellite symposium, held in conjunction with the European Society for Immunodeficiencies (ESID) 2010 meeting, to inform attendees about new scientific concepts in IgG therapy, with the goal of empowering expert level evaluation of what optimal IgG therapy is today.

Efficacy, safety, and pharmacokinetics of a 10% liquid immune globulin preparation (GAMMAGARD LIQUID, 10%) administered subcutaneously in subjects with primary immunodeficiency disease

A multi-center, prospective, open-label study was conducted in primary immunodeficiency disease patients to determine the tolerability and pharmacokinetics of a 10% liquid IgG preparation administered subcutaneously. Forty-nine subjects (3-77 years old) were enrolled. Pharmacokinetic equivalence of subcutaneous treatment was achieved at a median dose of 137% of the intravenous dose, with a mean trough IgG level of 1,202 mg/dL at the end of the assessment period. The overall infection rate during subcutaneous treatment was 4.1 per subject-year. Three acute serious bacterial infections were reported, resulting in a rate of 0.067 per subject-year. A low overall rate of temporally associated adverse events (8%), and a very low rate of infusion site adverse events (2.8%), was seen at volumes up to 30 mL/site and rates ≤ 30 mL/h/site. Thus, subcutaneous replacement therapy with a 10% IgG preparation proved effective, safe and well-tolerated in our study population of subjects with primary immunodeficiency disease.

Pharmacokinetics and safety of subcutaneous immune globulin (human), 10% caprylate/chromatography purified in patients with primary immunodeficiency disease

Subcutaneous administration of intravenous immunoglobulin G (IgG) preparations provides an additional level of patient convenience and more options for patients with poor venous access or a history of intravenous IgG reactions. An open-label, pharmacokinetic trial (n = 32) determined the non-inferiority of the subcutaneous versus intravenous route of 10% caprylate/chromatography purified human immune globulin intravenous (IGIV-C; Gamunex®) administration by comparing the steady-state area under the concentration-versus-time curve (AUC) of total plasma IgG in patients with primary immunodeficiency disease. Patients on stable IGIV-C received two intravenous infusions (administered 3 or 4 weeks apart). Seven to 10 days after the second intravenous infusion, all patients switched to a weekly infusion of subcutaneous IGIV-C, with the dose equal to 137% of the previous weekly equivalent intravenous dose, for up to 24 weeks. Samples for pharmacokinetic analysis were collected during steady state for intravenous and subcutaneous IGIV-C treatments. The AUC(0-) τ geometric least-squares mean ratio was 0·89 (90% confidence interval, 0·86-0·92) and met the criteria for non-inferiority. The overall mean steady-state trough concentration of plasma total IgG with subcutaneous IGIV-C was 11·4 mg/ml, 18·8% higher than intravenous IGIV-C (9·6 mg/ml). Subcutaneous IGIV-C was safe and well tolerated. Subcutaneous IGIV-C infusion-site reactions were generally mild/moderate and the incidence decreased over time. No serious bacterial infections were reported. Weekly subcutaneous IGIV-C infusion using 137% of the weekly equivalent intravenous immunoglobulin dose provides an AUC comparable to intravenous administration, thus allowing patients to maintain the same IgG preparation/formulation if switching between intravenous and subcutaneous infusions.

A multi-centre study of efficacy and safety of Intratect®, a novel intravenous immunoglobulin preparation

We studied the efficacy, safety and pharmacokinetic profiles of Intratect®, a recently developed polyvalent intravenous immunoglobulin (IVIG) preparation. Fifty-one patients (aged 6-48 years) with primary immunodeficiencies (PID) and established replacement therapy using a licensed IVIG were enrolled and treated for 12 months with Intratect®. Retrospective patient data served as prestudy controls. The primary efficacy variable was the annual rate of acute serious bacterial infection (ASBI) per patient. Secondary parameters were annual rate of acute relevant infection (ARI), days with antibiotic use, fever, absence from school/work and hospitalization. The average IVIG dose was 0·49 g/kg, with an average infusion rate of 2·4 ml/kg/h. The annual ASBI rate/patient was 0·02 and ARIs were detected 128 times during the 630 adverse events in 40 patients, specified mainly as bronchitis, sinusitis, respiratory tract infection, rhinitis and pharyngitis. The annual rate of respiratory ARIs/patient was 2·0 and the rates/patient for days with fever >38°C, school/work absence and hospitalization were 1·81, 3·99 and 0·36, respectively. A total of 630 adverse events (AEs) were observed in 50 of 51 (98·0%) of patients. In 46 of 51 patients the AEs were not related to infusion. Pharmacokinetic studies after the first infusion revealed a mean elimination half-life of 50·8 ± 30·3 days. During this study, 19 of 649 (2·9%) IgG trough levels were below 6 g/l, better than that of reference IVIGs during the 6 months before study start (10 of 201). These data suggest that Intratect® is a well tolerated, safe and effective IgG concentrate for the treatment of patients with PID.

Intravenous immunoglobulin induces proliferation and immunoglobulin synthesis from B cells of patients with common variable immunodeficiency: a mechanism underlying the beneficial effect of IVIg in primary immunodeficiencies

Common variable immunodeficiency (CVID) is associated with low serum immunoglobulin concentrations and an increased susceptibility to infections and autoimmune diseases. The treatment of choice for CVID patients is replacement intravenous immunoglobulin (IVIg) therapy. IVIg has been beneficial in preventing or alleviating the severity of infections and autoimmune and inflammatory process in majority of CVID patients. Although the mechanisms of action of IVIg given as 'therapeutic high dose' in patients with autoimmune diseases are well studied, the underlying mechanisms of beneficial effects of IVIg in primary immunodeficiencies are not completely understood. Therefore we investigated the effect of 'replacement dose' of IVIg by probing its action on B cells from CVID patients. We demonstrate that IVIg at low doses induces proliferation and immunoglobulin synthesis from B cells of CVID patients. Interestingly, B cell stimulation by IVIg is not associated with induction of B cell effector cytokine IFN-γ and of transcription factor T-bet. Together, our results indicate that in some CVID patients, IVIg rectifies the defective signaling of B cells normally provided by T cells and delivers T-independent signaling for B cells to proliferate. IVIg 'replacement therapy' in primary immunodeficiencies is therefore not a merepassive transfer of antibodies to prevent exclusively the recurrent infections; rather it has an active role in regulating autoimmune and inflammatory responses through modulating B cell functions and thus imposing dynamic equilibrium of the immune system.

Relevant criteria for selecting an intravenous immunoglobulin preparation for clinical use

Over the past several decades, the use of intravenous human normal immunoglobulin (IVIg) products in a diverse range of immunodeficiency, inflammatory and infectious disorders has increased significantly. Newer manufacturing processes have increased the yield of intact IVIg molecules and have also improved the tolerability and safety of these products, including reducing the transmission risk of blood-borne diseases. While there are no appreciable differences between the numerous commercially available IVIg products in terms of efficacy, different manufacturing processes and the final composition of IVIg products have resulted in different safety and tolerability profiles. The tolerability profile of different IVIg products may be idiosyncratic for individual patients and may not be predictable, based on product characteristics. Consequently, patients receiving an IVIg product should be carefully monitored at initial exposure, and switching of products should be avoided. To achieve the best outcomes in patients requiring IVIg therapy, treatment should be tailored to the patient's needs. The risk/benefit profile of an IVIg in relation to patient risk factors and the underlying immune deficiency, or autoimmune or inflammatory disorder should be considered when deciding on the most appropriate therapy.

Impact of trough IgG on pneumonia incidence in primary immunodeficiency: A meta-analysis of clinical studies

Primary immunodeficiency disease (PIDD) associated with hypogammaglobulinemia is typically treated with immunoglobulin replacement therapy. When administered as intravenous immunoglobulin (IVIG), an IgG trough occurs prior to the next replacement dose. While frequently measured, IgG trough levels required to minimize infection risk are not established. To address this question, all available studies evaluating trough IgG and pneumonia incidence in PIDD patients with hypogammaglobulinemia receiving IVIG were quantitatively combined by meta-analysis. Seventeen studies with 676 total patients and 2,127 patient-years of follow-up were included. Pneumonia incidence declined by 27% with each 100mg/dL increment in trough IgG (incidence rate ratio, 0.726; 95% confidence interval, 0.658-0.801). Pneumonia incidence with maintenance of 500 mg/dL IgG trough levels (0.113 cases per patient-year) was 5-fold that with 1000 mg/dL (0.023 cases per patient-year). This meta-analysis provides evidence that pneumonia risk can be progressively reduced by higher trough IgG levels up to at least 1000 mg/dL.

Infection outcomes in patients with common variable immunodeficiency disorders: relationship to immunoglobulin therapy over 22 years

BACKGROUND

Common variable immunodeficiency disorders (CVIDs) are the most common forms of symptomatic primary antibody failure in adults and children. Replacement immunoglobulin is the standard treatment, although there are few consistent data on optimal dosages and target trough IgG levels required for infection prevention.

OBJECTIVE

To provide data to support the hypothesis that each patient requires an individual dose of therapeutic immunoglobulin to prevent breakthrough infections and that efficacious trough IgG levels vary between patients.

METHODS

Data, collected prospectively from a cohort of 90 patients with confirmed CVIDs from 1 center over a follow-up period of 22 years, was validated and analyzed. Immunoglobulin doses had been adjusted in accordance with infections rather than to achieve a particular trough IgG level. Doses to achieve infection-free periods were determined and resultant trough levels analyzed. A smaller group of patients with X-linked agammaglobulinemia was analyzed for comparison.

RESULTS

Patients with a CVID had a range of trough IgG levels that prevented breakthrough bacterial infections (5-17 g/L); viral and fungal infections were rare. Doses of replacement immunoglobulin to prevent breakthrough infections ranged from 0.2 to 1.2 g/kg/mo. Those with proven bronchiectasis or particular clinical phenotypes required higher replacement doses. Patients with X-linked agammaglobulinemia showed a similar range of IgG levels to stay infection-free (8-13 g/L).

CONCLUSION

These data offer guidance regarding optimal doses and target trough IgG levels in individual patients with CVIDs with or without bronchiectasis and for particular clinical phenotypes. The goal of replacement therapy should be to improve clinical outcome and not to reach a particular IgG trough level.

Efficacy and safety of a new 20% immunoglobulin preparation for subcutaneous administration, IgPro20, in patients with primary immunodeficiency

Subcutaneous human IgG (SCIG) therapy in primary immunodeficiency (PID) offers sustained IgG levels throughout the dosing cycle and fewer adverse events (AEs) compared to intravenous immunoglobulin (IVIG). A phase I study showed good local tolerability of IgPro20, a new 20% liquid SCIG stabilized with L-proline. A prospective, open-label, multicenter, single-arm, phase III study evaluated the efficacy and safety of IgPro20 in patients with PID over 15 months. Forty-nine patients (5–72 years) previously treated with IVIG received weekly subcutaneous infusions of IgPro20. The mean serum IgG level was 12.5 g/L. No serious bacterial infections were reported. There were 96 nonserious infections (rate 2.76/patient per year). The rate of days missed from work/school was 2.06/patient per year, and the rate of hospitalization was 0.2/patient per year. Ninety-nine percent of AEs were mild or moderate. No serious, IgPro20-related AEs were reported. IgPro20 effectively protected patients with PID against infections and maintained serum IgG levels without causing unexpected AEs.

Primary antibody deficiencies: recognition, clinical diagnosis and referral of patients

The primary antibody deficiency syndromes are a rare group of immunodeficiencies where diagnostic delay remains common due to limited awareness of the existence and heterogeneity of their presenting features. Referral for specialist assessment leads to earlier diagnosis and appropriate therapy to prevent or limit structural organ and tissue damage. Greater education of healthcare professionals is required to ensure prompt recognition and referral to specialists with expertise in the care of primary immunodeficiencies, especially since study of these rare conditions is a minor part of undergraduate and general postgraduate training. Greater awareness would lead to reduced morbidity, improved quality of life and survival outcomes in this patient group.

Update in understanding common variable immunodeficiency disorders (CVIDs) and the management of patients with these conditions

The common variable immunodeficiency disorders are a mixed group of heterogeneous conditions linked by lack of immunoglobulin production and primary antibody failure. This variability results in difficulty in making coherent sense of either immunopathogenesis or the role of various genetic abnormalities reported in the literature. The recent attempt to collate the varied complications in these conditions and to define particular clinical phenotypes has improved our understanding of these diseases. Once refined and confirmed by other studies, these definitions will facilitate improved accuracy of prognosis and better management of clinical complication. They may also provide a method of analysing outcomes as related to new immunopathological and genetic findings.

History of immunoglobulin replacement

The provision of antibodies to prevent and treat infection began with the application of "curative serum" in the first years of the last century. After the process of large-scale plasma fractionation was developed in the 1940s, the general use of immunoglobulin expanded. Intravenous immunoglobulin products became available in the 1970s, and their only use for the provision of antibodies governed the opinion of experts over the next decade. Modulation of inflammation and immunosuppression were introduced in treatment of inflammatory and autoimmune diseases and became accepted indications. The history of adverse events of treatment and their management are outlined in this article. Consensus indications and evidence-based off-label uses are discussed.

Immunoglobulin replacement therapy in children

The benefit of immunoglobulin (IG) replacement in primary antibody deficiencies is unquestionable. Many of these congenital disorders present early in life and this therapy is often first implemented in the young. This article focuses on the indications of IG replacement in children, with an emphasis on the specific diagnostic problems encountered in this population. Also presented is an overview of the practical aspects of IG administration in the pediatric setting, including the recognition and management of adverse reactions. Finally, the advent of subcutaneous IG, a therapeutic IG modality with the potential to have a great impact on the quality of life of children with antibody deficiencies and their families, is discussed.

Clinical immunology review series: An approach to the management of pulmonary disease in primary antibody deficiency

The sinopulmonary tract is the major site of infection in patients with primary antibody deficiency syndromes, and structural lung damage arising from repeated sepsis is a major determinant of morbidity and mortality. Patients with common variable immunodeficiency may, in addition, develop inflammatory lung disease, often associated with multi-system granulomatous disease. This review discusses the presentation and management of lung disease in patients with primary antibody deficiency.

Safety and efficacy of Privigen, a novel 10% liquid immunoglobulin preparation for intravenous use, in patients with primary immunodeficiencies

PURPOSE

The present study was designed to evaluate the efficacy and safety of a novel, 10% liquid formulation of intravenous immunoglobulin, stabilized with 250 mmol/L L-proline (Privigen), in patients with primary immunodeficiency disease.

MATERIALS AND METHODS

Eighty adults and children diagnosed with common variable immunodeficiency or X-linked agammaglobulinemia received intravenous Privigen infusions (200-888 mg/kg) at 3- or 4-week intervals over a 12-month period, according to their previously established maintenance dose. The primary endpoint was the annual rate of acute serious bacterial infections.

RESULTS

There were six episodes of acute serious bacterial infections, corresponding to an annual rate of 0.08; the annual rate for all infections was 3.55. Mean serum IgG trough levels were between 8.84 and 10.27 g/L. A total of 1,038 infusions were administered, most of them at the maximum rate permitted (8.0 mg kg(-1) min(-1)). Temporally associated adverse events, possibly or probably related to study drug, occurred in 9% of infusions, either during or within 72 h after infusion end.

CONCLUSION

Privigen is well tolerated and effective for the treatment of primary immunodeficiency.

Principles of and advances in immunoglobulin replacement therapy for primary immunodeficiency

During the last 2 decades, the continued development and the large-scale production of polyclonal immune serum globulin (ISG) preparations with improved safety and tolerability profiles have allowed treatment to focus on quality of life and long-term freedom from the complications of primary immune deficiency disease, rather than just on freedom from severe acute infections and survival. Available ISG preparations allow routine therapy by a variety of routes and regimens that can be tailored to suit individual patients. Continued vigilance is required, however, because problems with emerging diseases, and the costs and availability of ISG are likely to present continuing challenges.

The use of i.v. IG therapy in dermatology

The intravenous administration of exogenous pooled human immunoglobulin (i.v. IG) was originally licensed as antibody replacement therapy in patients with primary immunodeficiencies and there are currently six FDA-approved uses for this agent. Despite a current lack of FDA approval, off-label treatment of a multitude of dermatologic disorders with i.v. IG has shown exciting potential for this unique treatment modality. The diseases successfully treated with i.v. IG include autoimmune bullous diseases, connective tissue diseases, vasculitides, toxic epidermal necrolysis, and infectious disorders (such as streptococcal toxic shock syndrome). Currently the biggest drawback in the consideration of i.v. IG therapy in dermatologic disorders is the lack of randomized controlled trials. Nevertheless, there is a significant body of evidence demonstrating the efficacy of i.v. IG in patients with dermatologic disorders that are resistant to treatment with standard agents. In summary, i.v. IG constitutes a valuable and potentially life-saving agent in managing patients with a variety of dermatologic disorders under the appropriate circumstances.

Recognition, clinical diagnosis and management of patients with primary antibody deficiencies: a systematic review

The primary purpose of this systematic review was to produce an evidence-based review of the literature as a means of informing current clinical practice in the recognition, diagnosis and management of patients with suspected primary antibody deficiency. Randomized controlled trials (RCTs) were identified from a search of MEDLINE, EMBASE, The Cochrane Library, DARE (CRD website) and CINAHL by combining the search strategies with The Cochrane Collaboration's validated RCT filter. In addition, other types of studies were identified in a separate search of MEDLINE and EMBASE. Patients at any age with recurrent infections, especially in the upper and lower respiratory tracts, should be investigated for possible antibody deficiency. Replacement therapy with immunoglobulin in primary antibody deficiencies increases life expectancy and reduces infection frequency and severity. Higher doses of immunoglobulin are associated with reduced infection frequency. Late diagnosis and delayed institution of immunoglobulin replacement therapy results in increased morbidity and mortality. A wide variety of organ-specific complications can occur in primary antibody deficiency syndromes, including respiratory, gastroenterological, hepatic, haematological, neurological, rheumatological and cutaneous. There is an increased risk of malignancy. Some of these complications appear to be related to diagnostic delay and inadequate therapy. High-quality controlled trial data on the therapy of these complications is generally lacking. The present study has identified a number of key areas for further research, but RCT data, while desirable, is not always obtained easily for rare conditions. Few data from registries or large case-series have been published in the past 5 years and a greater focus on international collaboration and pooling of data is needed.

Carimune NF Liquid is a safe and effective immunoglobulin replacement therapy in patients with primary immunodeficiency diseases

Subjects with primary immune deficiency diseases treated with intravenous immunoglobulin (n=42) received intravenous infusions of Carimune NF Liquid every 3-4 weeks for 6 months without routine premedication. The mean dose/patient/infusion was 278.5-800.7 mg/kg. Also, 80.4% of infusions achieved maximum rates of >or=3.5 mg/kg/min; 32% of infusions were associated with adverse events during or within 48 h of their end (upper 95% confidence interval was 39.4%, meeting the Food and Drug Administration (FDA) criterion for acceptable tolerability), and 54.8% of subjects had at least one temporally associated adverse event considered at least possibly drug-related (headache: 35.7% of subjects, 12.4% of infusions; nausea: 14.3%, 3.5%; myalgia: 14.3%, 3.2%; fatigue: 11.9%, 5.7%). The frequencies of these were highest after the first infusion. There were no serious drug-related adverse events or acute serious bacterial infections. Serum IgG trough levels were unchanged from baseline. Carimune NF Liquid, a ready-to-use, high-concentration, liquid immunoglobulin preparation is safe and effective.

Off-label uses of biologics in dermatology: Interferon and intravenous immunoglobulin (Part 1 of 2)

The introduction of a number of biologic therapies into the market has revolutionized the practice of dermatology. These therapies include interferons, intravenous immunoglobulin, infliximab, adalimumab, etanercept, efalizumab, alefacept, and rituximab. Most dermatologists are familiar with the Food and Drug Administration-approved indications of these medications. However, numerous off-label uses have evolved. As part 1 of a 2-part series, this article will review the literature regarding the off-label uses of the interferons and intravenous immunoglobulin in dermatology.

Comparative study of the anti-inflammatory effect of two intravenous immunoglobulin preparations manufactured by different processes

Intravenous immunoglobulin (IVIG) is increasingly used in the treatment of diverse immune-mediated disorders. Since several preparations of IVIG are available for therapy, it is possible that different manufacturing processes might influence clinical efficacy of IVIG. An insight into the mechanisms of action of such different IVIG preparations is therefore necessary that will provide further guidelines for the utility of IVIG preparations in autoimmune and inflammatory diseases. Since endothelial cells (EC) influence the inflammatory process via production of cytokines, chemokines and expression of adhesive molecules, we analyzed the anti-inflammatory effect on EC of two IVIG preparations: caprylated IVIG (IVIG-C) versus solvent/detergent-treated IVIG (IVIG-SD) preparation. We found that both IVIG preparations inhibit in an equivalent manner, the expression of different pro-inflammatory factors such as IL-6, IL-8, GM-CSF, IL-1beta and TNF-alpha and the adhesion molecules ICAM-1 and VCAM-1. Our results thus suggest that the caprylate while inactivating the virus and enhancing the yield of IgG during IVIG formulation, does not modulate the immunomodulatory properties of IVIG at EC level and that the two preparations show similar anti-inflammatory effects.

Safety and tolerability of increased rate of infusion of intravenous immunoglobulin G, 10% in antibody-deficient patients

The incidence and severity of infusion-related adverse events (AEs) after infusions of IGIV-C, 10%, (Gamunex) at 0.14 mL/kg/min versus 0.08 mL/kg/min (standard rate) were compared. Patients with confirmed PID received two infusions 3-4 weeks apart with IGIV-C, 10% 400-600 mg/kg. Patients received their first infusion at 0.08 or 0.14 mL/kg/min and their second infusion 3-4 weeks later at the alternate rate, at an established step-wise rate increase. Ninety-seven of 100 patients remained valid for safety assessment. There were three infusion-related reactions at the standard rate and five at the increased rate. The incidence of all reported AEs was similar for both rates. Despite the time required for step-wise increases in infusion rate, the increased rate resulted in a shortened overall infusion time. Increasing the rate of infusion of IGIV-C, 10% by 75% up to 0.14 mL/kg/min (840 mg/kg/h) was well tolerated, suggesting safe administration of IGIV-C, 10% at this rate.

Efficacy, safety and tolerability of a new 10% liquid intravenous immune globulin [IGIV 10%] in patients with primary immunodeficiency

The present clinical study was designed to evaluate the efficacy, pharmacokinetics and safety of a new 10% liquid intravenous immune globulin in patients with primary immunodeficiency diseases. Sixty-one adults and children with primary immuno-deficiency diseases received doses of 300-600 mg/kg body weight every 21-28 days for 12 months. No validated acute serious bacterial infections were reported. The 95% confidence interval for the annualized rate of acute serious bacterial infections (primary endpoint) was 0-0.060. A total of four predefined validated other bacterial infections commonly occurring in primary immunodeficiency disease subjects were observed; none were serious, severe or resulted in hospitalization. The median elimination half-life of IgG was 35 days. Median total IgG trough levels varied from 9.6 to 11.2 g/L. Temporally associated adverse experiences were determined for 72 h after each infusion and the most common adverse experience was headache, which was associated with 6.9% of infusions. The study met the primary endpoint for efficacy and demonstrated excellent tolerability of the new 10% liquid intravenous imunoglobulin preparation.

Protocol Recommendations for Administration of Intravenous Immunoglobulin in Canada

A group of Canadian nurses and transfusion safety officers developed 10 recommendations for the infusion of intravenous immunoglobulin (IVIG) in acute care hospitals and clinics. The recommendations address issues related to documentation, patient consent, difference among IVIG brands, selection of a brand on the basis of patients' risk factors, contraindications, needs, action plans for adverse events, rapid infusion protocols, and setup of infusion pumps, tubing, and filter equipment. The Canadian group encouraged institutions to include nurses on committees that examine infusion protocols.

Prospective open-label study of pharmacokinetics, efficacy and safety of a new 10% liquid intravenous immunoglobulin in patients with hypo- or agammaglobulinemia

BACKGROUND AND OBJECTIVES

The aim of this study was to evaluate the pharmacokinetics, efficacy and safety of a newly developed 10% liquid immunoglobulin preparation in patients with primary immunodeficiency diseases. This new preparation for intravenous use includes three dedicated virus clearance steps in its manufacturing process to ensure a high margin of viral safety.

MATERIALS AND METHODS

This was a prospective, open-label, non-controlled, multicentre study. Twenty-two subjects with primary immunodeficiency were treated initially with three infusions of a licensed intravenous immunoglobulin to standardize the immunoglobulin G (IgG) replacement therapy of all subjects to the same intravenous product. A total of nine infusions of the new 10% liquid preparation were subsequently administered.

RESULTS

The median terminal half-life of total IgG following administration of the new preparation was 30.1 days. Median terminal half-lives for IgG subclasses IgG(1), IgG(2), IgG(3) and IgG(4) were 28.3, 31.3, 20.9 and 24.2 days, respectively. The median total serum IgG steady-state trough level was 8.51 g/l. No severe infection episodes started after initiation of treatment with the new preparation. The median rate of mild or moderate infection episodes was 0.48 per month. A total of 194 infusions with the new 10% liquid immunoglobulin preparation were administered. The mean dose per infusion was 0.41 g/kg body weight and the maximum infusion rates recorded were 8 ml/kg/h. Adverse experiences were mostly mild and unrelated to the study drugs. Only 4% of infusions with the new product were followed by one or more related adverse experiences.

CONCLUSION

The new 10% liquid immunoglobulin preparation was well tolerated and shown to have an excellent pharmacokinetic, efficacy and safety profile. The liquid formulation provides convenience to patients and healthcare professionals.

The pocketbook: Pharmacoeconomic issues related to intravenous immunoglobulin therapy

Two analyses were conducted to compare the cost-effectiveness of different intravenous immunoglobulin (IGIV) formulations: IGIV purified by caprylate precipitation and chromatography (IGIV-C) and IGIV manufactured by an older solvent-detergent method (IGIV-S/D). The results indicated that IGIV-C is associated with cost savings for patients with primary immunodeficiency or idiopathic (immune) thrombocytopenic purpura (ITP). With primary immunodeficiency, the largest cost driver was hospitalizations, whereas with ITP, it was ancillary product use and, more specifically, additional IGIV therapy. Although differences were noted between the two IGIV formulations, the long-term cost consequences of administering these IGIV products are unclear. Further work is necessary to determine whether the results of these analyses can be generalized beyond these particular patients and to evaluate the effects on long-term health care costs.

The product: All intravenous immunoglobulins are not equivalent

The first intravenous formulation of intravenous immunoglobulin (IGIV) was introduced in the United States in the early 1980s. At that time, the only indication was for treatment of primary immunodeficiency. By the mid-1990s, IGIV was mainly used for indications approved by the United States Food and Drug Administration, but as new indications are found, use of IGIVs is increasing. In fact, today, IGIV is mostly used for off-label indications. The specific characteristics of individual IGIV products must be directly addressed in the manufacturing process, as clinical efficacy may be affected. In addition, the safety profile of the ideal IGIV should be maximized by ensuring inactivation of the widest spectrum of viruses and prions. Some IGIV products are more suitable than others for certain patients; the challenge is to understand the different characteristics among products and select the most appropriate IGIV product for each patient. Convenience factors must be considered, for both the health care provider and the patient, without jeopardizing the more important features of the IGIV, such as tolerability and safety.

Differences between IGIV products: impact on clinical outcome

The use of immune globulin intravenous (IGIV) as replacement therapy in immunodeficiency disease and as anti-inflammatory or immunomodulatory therapy in a variety of autoimmune and inflammatory diseases has expanded dramatically over the last decade. With this expansion, new challenges and concerns have emerged. As well, new products have been introduced while others have been discontinued. This evolution poses the important issue of product selection, choosing the "right" product for an individual patient. As the manufacturing process, virus reduction methods, and final formulation and composition differ widely among these products, it is intuitive that clinical outcomes, including both safety and efficacy, could also differ. This review examines such differences among currently available products in the United States and their potential to affect clinical outcomes.

Use of intravenous immunoglobulin G (IVIG)

Intravenous immunoglobulin G (IVIG) has become increasingly important both as replacement therapy in primary and acquired humoral immunodeficiency and as an immunomodulatory therapy in autoimmune disease and transplantation. Multiple potential mechanisms for the effects of IVIG have now been recognized but the contribution of each mechanism in different diseases is uncertain. IVIG is generally well tolerated but serious side effects can occur and need to be addressed. IVIG has Food and Drug Administration (FDA) approval for a half dozen indications but these account for only about half the use of IVIG. This chapter reviews the development of IVIG for primary immunodeficiency, the evidence for efficacy of IVIG in autoimmune and inflammatory conditions, the risks associated with administration of IVIG, and steps that can be taken to minimize adverse events.

Critical Decisions in Selecting an Intravenous Immunoglobulin Product

Use of intravenous immunoglobulin (IVIG) therapy has expanded enormously in the past two to three decades, targeting a large number of autoimmune and inflammatory disorders as well as primary immunodeficiency disease, human immunodeficiency virus, and Kawasaki disease. Increased use, particularly at higher doses and in older patients, has presented certain challenges related to safety and tolerability. All IVIGs are not the same. They differ in manufacturing processes, methods of virus elimination, and final composition. Carefully evaluating patient risk factors and matching them to potential IVIG product risks and benefits are becoming increasingly important in the selection of a particular IVIG.

Cost savings from intravenous immunoglobulin manufactured from chromotography/caprylate (IGIV-C) in persons with primary humoral immunodeficiency disorder

OBJECTIVE

Human intravenous immunoglobulin manufactured with chromatography and caprylate methods (IGIV-C, 10%) was associated with a reduction in validated infections (pneumonia and sinusitis) compared with treatment with a licensed immunoglobulin product manufactured using standard solvent-detergent methods (IGIV-SD, 10%) in participants with primary humoral immunodeficiency disorder (PIDD). Our objective was to determine the cost-consequences of using IGIV-C instead of IGIV-SD.

METHODS

Economic analysis of a double-blind, randomized, clinical trial was used. Participants were randomly assigned to IGIV-C (N = 87) or IGIV-SD (N = 85) and monitored for the development of validated infections over the course of 9 months. Consumed resources were enumerated including cost of physician and emergency room visits, medications (prescription and over-the-counter), work productivity losses, and hospitalizations. Resource data was obtained from case report forms, patient diaries and the trial medication database. Because the amount of IGIV-SD used exceeded that of IGIV-C (nonstatistically significant difference) and the products are equivalently priced, we conservatively excluded investigational product acquisition cost to avoid artificially biasing incremental cost differences. We used a societal perspective with indirect costs, measured in 2003 US dollars. Pricing of both IGIV products is anticipated to be equivalent.

RESULTS

In a multivariate analysis, annual mean per participant costs were significantly lower between those receiving IGIV-C compared with IGIV-SD for prescription medications [-US 302 dollars, 95% confidence interval (CI) -US 598 dollars to -US 6 dollars], hospitalization (-US 1454 dollars, 95% CI -US 1828 dollars to -US 1080 dollars) and total costs (-US 1304 dollars, 95% CI -US 1867 dollars to -US 742 dollars). Costs associated with lost work productivity and physician visits were similar in both groups (P > 0.10). In sensitivity analyses, varying costs of concomitant medications, hospitalization and outpatient care, did not significantly change our results.

CONCLUSION

IGIV-C is cost-saving compared with IGIV-SD among persons with PIDD.

Clinical immunology in practice, new opportunities

While research provides new opportunities for diagnosing and treating patients with allergic and immunological disorders, there are significant challenges to putting these advances into use in clinical practice. Each new test may require clinicians in private practice to battle with a health insurer's designated clinical laboratory in an effort to get this new test and other accurate immunological laboratory studies. A new test may or may not be covered by some health care plans and may or may not be available from their designated laboratories. Many of these laboratories send time-sensitive samples across the country with risk of time delays and poor specimen handling leading to inaccurate results and/or the need to send repeat specimens. The growing role of managed care in every medical decision has led to frustrations for the patient and physician. This frequently requires a consult at a tertiary care center, where laboratory studies may be more easily accessible with fewer restrictions. Where are the new opportunities? Some are found in the enhanced ability to make intelligent decisions in the diagnosis and treatment of immunological diseases. There is now a greater selection and availability of intravenous gamma-globulin (IVIG), that can be matched to individual patient needs. The appropriate selection of these products will decrease adverse reactions and increase safety. There was a major advance in the treatment of moderate and severe asthma with the addition of omalizumab therapy. It provides allergists and immunologists with their first monoclonal humanized anti-IgE antibody.

A prospective controlled crossover trial of a new presentation (10% vs. 5%) of a heat-treated intravenous immunoglobulin

Thirty-five patients with primary or secondary immunoglobulin deficiency were included in a crossover study to test the tolerance, clinical efficacy, and safety of a liquid pasteurized 10% concentrated intravenous gammaglobulin versus a 5% concentrated presentation. No statistically significant differences were found between these parameters. Total serum immunoglobulin-(Ig)G and IgG subclass levels were similar in both groups. No modifications in serum alanine transferase (ALT) levels and viral status (HBsAg, HCV-RNA, p24 antigen or RNA for HIV) were observed throughout treatment. Adverse reactions were reported in 3 out of 70 infusions (4.3%), 2 in the experimental group and 1 in the control group. The maximum recommended rate of infusion for the 10% gammaglobulin is the same as for the 5% gammaglobulin product (0.04 ml/kg/min); generally speaking, this means that infusion time is halved. We conclude that a 10% gammaglobulin product is a well-tolerated, clinically efficacious and safe intravenous preparation, and that it could be a short infusion time alternative for primary and secondary antibody deficiencies.

Treatment of paediatric non-cystic fibrosis bronchiectasis

Non-cystic fibrosis (CF) bronchiectasis, the abnormal dilatation of bronchial airways, is a heterogeneous condition caused by a variety of lung insults and results in significant morbidity and mortality. Although frequently reported as being an uncommon respiratory disease in the developed world, its impact on the respiratory health of specific populations has recently received increased attention. There are limited data on which to base management strategies. This article reviews the evidence for current treatment practices, provides an opinion on best practice, and discusses likely new therapies. Consideration is also given to the pharmacoeconomic hurdles that face the populations most affected.

Immunoglobulin replacement therapy in primary antibody deficiency diseases--maximizing success

Antibody or humoral immunodeficiencies comprise the largest group of primary immunodeficiency diseases. Since the first description of patients with low gammaglobulin levels more than four decades ago, a great wealth of information has been accumulated. Especially in the last several years, the application of molecular and genetic techniques has unraveled many of these disorders, identifying disorders of B cell development, failure of class switch recombination and abnormalities of specific antibody production. Regardless of the underlying defect, the mainstay of therapy has been and remains immunoglobulin (Ig) replacement therapy, currently by intravenous infusion or subcutaneous injection. With advances in manufacturing, a number of products are not only safe for intravenous administration but doses can be increased to provide even more effective infection prophylaxis. However, manufacturing processes, methods of viral inactivation and removal and final composition differ widely among the available preparations. How these variables impact clinical outcome is not clear, but they have the potential to do so. As a result, careful selection of an intravenous immunoglobulin (IVIG), matching patient needs and risks to those risks associated with a specific IVIG, is necessary to optimize outcomes and maximize the success of Ig replacement therapy.

The use of intravenous immunoglobulin in the treatment of autoimmune neuromuscular diseases: evidence-based indications and safety profile

Intravenous immunoglobulin (i.v.Ig) has multiple actions on the immunoregulatory network that operate in concert with each other. For each autoimmune neuromuscular disease, however, there is a predominant mechanism of action that relates to the underlying immunopathogenetic cause of the respective disorder. The best understood actions of i.v.Ig include the following: (a) modulation of pathogenic autoantibodies, an effect relevant in myasthenia gravis (MG), Lambert-Eaton myasthenic syndrome (LEMS), Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), and stiff-person syndrome (SPS); (b) inhibition of complement activation and interception of membranolytic attack complex (MAC) formation, an action relevant to the complement-mediated mechanisms involved in GBS, CIDP, MG, and dermatomyositis (DM); (c) modulation of the inhibitory or activation Fc receptors on macrophages invading targeted tissues in nerve and muscle, as seen in CIDP, GBS, and inflammatory myopathies; (d) down-regulation of pathogenic cytokines and adhesion molecules; (e) suppression of T-cell functions; and (f) interference with antigen recognition. Controlled clinical trials have shown that i.v.Ig is effective as first-line therapy in patients with GBS, CIDP, and multifocal motor neuropathy (MMN), and as second-line therapy in DM, MG, LEMS, and SPS. In paraproteinemic IgM anti-MAG (myelin-associated glycoprotein) demyelinating polyneuropathies and inclusion body myositis (IBM), the benefit is variable, marginal, and not statistically significant. i.v.Ig has a remarkably good safety record for long-term administration, however, the following side effects have been observed: mild, infusion-rate-related reactions, such as headaches, myalgia, or fever; moderate but inconsequential events, such as aseptic meningitis and skin rash; and severe, but rare, complications, such as thromboembolic events and renal tubular necrosis. Future studies are needed to (a) find the appropriate dose and frequency of infusions that maintain a response; (b) address pharmacoeconomics, comparing the high cost of i.v.Ig to the cost of the other therapies, which, although less expensive, cause significantly more long-term side effects; (c) determine why some patients respond better than others; and (d) examine the merits of combining i.v.Ig with other immunosuppressive drugs.

Subcutaneous immunoglobulin replacement in primary immunodeficiencies

The use of small portable pumps for subcutaneous infusion of IgG in patients with primary immunodeficiencies was introduced more than 20 years ago. In the US, i.v.i.g. became more popular, but in other countries, many patients use the subcutaneous route. Pharmacokinetics of IgG differ when smaller doses are given more frequently, as is commonly done with subcutaneous regimens, as compared to the large boluses given every 21-28 days in most i.v. regimens. Differences include lower peaks and higher troughs, which may be preferable for some patients. Advantages of the subcutaneous route include increased patient autonomy, decreased systemic adverse effects, and the lack of a requirement for vascular access. Disadvantages include limitation in the volume that can be administered at any one time, necessitating frequent dosing; and the requirement for reliability if a patient is to self or home infuse. Obstacles may be encountered because no preparation of IgG is currently licensed for subcutaneous use in the US. Subcutaneous IgG replacement may be preferable to i.v. infusions or i.m. injections for carefully selected patients.

Intravenous immunoglobulin for infectious diseases: back to the pre-antibiotic and passive prophylaxis era?

The dramatic increase in both the number of novel infectious agents and resistance to antimicrobial drugs has incited the need for adjunct therapies in the war against infectious diseases. Exciting recent studies have demonstrated the use of antibodies in the form of intravenous immunoglobulin (IVIg) against infections. By virtue of the diverse repertoire of immunoglobulins that possess a wide spectrum of antibacterial and antiviral specificities, IVIg provides antimicrobial efficacy independently of pathogen resistance and represents a promising alternative strategy for the treatment of diseases for which a specific therapy is not yet available.