Rubella antibodies in Australian immunoglobulin products.

Rubella antibodies are not routinely measured in immunoglobulin products and there is a lack of information on the titer in Australian products. To facilitate future studies of the effectiveness of passive immunisation for preventing rubella and congenital rubella syndrome, this study measured the concentration of rubella-specific antibodies in Australian intramuscular (IM) and intravenous (IV) human immunoglobulin products suitable for post-exposure prophylaxis using a chemiluminescent immunoassay. The GMT ± GSD for the IM product was 19 ± 1.2 IU/mg (2980 ± 1.2 IU/mL). The GMT ± GSD for the IV product was 12 ± 1.5 IU/mg (729 ± 1.5 IU/mL). At present, Australian guidelines recommend offering non-immune pregnant women exposed to rubella 20 mL of intramuscular immunoglobulin within 72 hours of exposure. This equates to 42,160 IU of rubella antibodies if the lowest titer obtained for the Australian IM product is considered. The same dose would be delivered by 176 mL of the Australian IV product at the lowest measured rubella-specific antibody titer.

Intravenous Immunoglobulin Protects Against Severe Pandemic Influenza Infection.

Influenza is a highly contagious, acute, febrile respiratory infection that can have fatal consequences particularly in individuals with chronic illnesses. Sporadic reports suggest that intravenous immunoglobulin (IVIg) may be efficacious in the influenza setting. We investigated the potential of human IVIg to ameliorate influenza infection in ferrets exposed to either the pandemic H1N1/09 virus (pH1N1) or highly pathogenic avian influenza (H5N1). IVIg administered at the time of influenza virus exposure led to a significant reduction in lung viral load following pH1N1 challenge. In the lethal H5N1 model, the majority of animals given IVIg survived challenge in a dose dependent manner. Protection was also afforded by purified F(ab')2 but not Fc fragments derived from IVIg, supporting a specific antibody-mediated mechanism of protection. We conclude that pre-pandemic IVIg can modulate serious influenza infection-associated mortality and morbidity. IVIg could be useful prophylactically in the event of a pandemic to protect vulnerable population groups and in the critical care setting as a first stage intervention.

Do Australian immunoglobulin products meet international measles antibody titer standards?

The effectiveness of passive immunisation post-exposure to measles appears subject to a dose-response effect. New Zealand and the United Kingdom have increased the recommended dose of polyclonal human immunoglobulin for post-exposure prophylaxis within the last decade in response to concerns about decreasing levels of measles antibodies in these products. This study used the plaque-reduction neutralization test (PRNT) to measure the titer of measles-specific antibodies in Australian immunoglobulin products for post-exposure prophylaxis and compared the utility of an enzyme-linked immunosorbent assay (ELISA) to the PRNT in available Australian and international samples: Australian intramuscular (n = 10), Australian intravenous (n = 28), New Zealand intramuscular (n = 2), Hizentra (subcutaneous)(USA) (n = 3), and Privigen (intravenous)(USA) (n = 2). Measles titres in Australian IM and IV immunoglobulins ranged from 51 to 76 IU/mL and 6 to 24 IU/mL respectively, as measured by PRNT calibrated to the WHO 3rd international standard. ELISA titres were variable but higher than PRNT titres in all tested samples. Measles antibody titres in Australian immunoglobulin products meet consensus-prescribed international thresholds. Development of a convenient, standardized, readily accessible assay for determination of measles titres in immunoglobulin products would be useful for future studies and facilitate international comparisons.

Efficacy, safety and pharmacokinetics of a novel subcutaneous immunoglobulin, Evogam®, in primary immunodeficiency.

This phase III, open-label, multi-centre study investigated the efficacy, safety, pharmacokinetics and quality of life impact of Evogam(®), a new chromatographically fractionated 16% subcutaneous immunoglobulin, utilising a 1:1 dose transition ratio from previous immunoglobulin therapy. Thirty-five previously treated patients with primary immunodeficiency received weekly Evogam over 36 weeks. Primary endpoints were rate of serious bacterial infections (SBIs) and steady-state serum immunoglobulin G (IgG) trough concentrations. No SBIs were reported during the study. Evogam produced significantly higher mean trough IgG concentrations with 1:1 dose conversion compared to previous immunoglobulin treatment (8.94 versus 8.27 g/L, p = 0.0063). Evogam was efficacious in the prevention of infections and maintenance of trough levels using a 1:1 dose conversion. It was well tolerated with no withdrawals due to adverse events and was preferred to IVIg by the majority of patients.

The use of hyperimmune serum for severe influenza infections*.

BACKGROUND AND PURPOSE: Although use of hyperimmune serum to treat patients with severe influenza infection, infections resistant to antiviral drugs, or as an interim therapy during a pandemic is frequently proposed, there have been no randomized case-control trials to investigate its efficacy. Reports of the use of hyperimmune serum in human influenza infection are sporadic and studies in animal models are limited. METHODS: Ferrets exposed to an otherwise lethal dose of highly pathogenic avian influenza H5N1 were used as a model of severe human disease. Hyperimmune serum was administered 24 hrs before virus exposure, during early fever, or at the onset of initial clinical signs of influenza (lethargy, lack of appetite) to reflect clinically relevant intervention points. Animals were monitored for 14 days after challenge and assessed for local and constitutional signs of influenza as measured by survival, weight loss, activity scores, viral shedding, and seroconversion. RESULTS: All animals administered hyperimmune serum homologous to the challenge virus before challenge survived the infection with no significant morbidity. The majority of animals receiving hyperimmune serum after virus exposure and during early fever survived the period of observation but showed significant morbidity and prolonged convalescence. The majority of animals that received serum later in the disease course died of acute infection. CONCLUSION: In highly pathogenic systemic influenza infections, the window for successful intervention by administration of hyperimmune serum may be narrow.

Comparison of the pharmacokinetics of two von Willebrand factor concentrates [Biostate and AHF (High Purity)] in people with von Willebrand disorder. A randomised cross-over, multi-centre study.

Plasma-derived factor concentrates are important in the management of von Willebrand disorder (VWD). In our geographic locality, a single viral inactivation step concentrate (AHF [High Purity]), has been replaced with one using a double viral inactivation step (Biostate). The aim of this study was to compare the pharmacokinetics of von Willebrand factor (VWF) and factor VIII (FVIII) after administration of AHF (High Purity) and Biostate. This study was a single-blind, randomised cross-over, multi-centre investigation in twelve people with VWD, comprising four type 3, two type 2B, one type 2M and five type 1 VWD. The subjects received a single infusion of 60 IU/kg ristocetin cofactor activity (VWF:RCo) of either AHF (High Purity) or Biostate, and after a minimum 15-day wash-out period they received the alternative product. Blood samples were collected for up to 48 hours after each dose for assay of FVIII coagulant activity (FVIII:C) and VWF by VWF:RCo, collagen binding capacity (VWF:CB) and antigen (VWF:Ag). As a measure of delivered VWF 'functionality' we calculated the area-under-the-concentration-time-curve (AUC) ratios of VWF:RCo to VWF:Ag and VWF:CB to VWF:Ag. The effect on platelet adhesiveness by PFA-100 closure times (CTs) was measured prior to and 30 minutes post infusion. VWF multimers were also assessed pre and post infusion. Pharmacokinetic parameters after AHF (High Purity) and Biostate were in close agreement for VWF:RCo (confirming dosing equivalence). Parameters for other study markers were also similar, although Biostate tended to yield relatively lower VWF:Ag and higher VWF:CB levels. Although AHF (High Purity) and Biostate resulted in similar levels of high-molecular-weight (HMW) multimers post-infusion, the relative level of HMW to low-molecular-weight (LMW) multimers were determined to be higher following Biostate. The relative levels of functional VWF (i.e. VWF:CB and VWF:RCo) to VWF:Ag were also higher in Biostate compared to AHF (High Purity). With both study products, PFA-100 CTs 30 minutes post infusion showed minor improvement for only some subjects. In conclusion, the pharmacokinetics of FVIII:C and VWF are not significantly different after administration of AHF (High Purity) and Biostate. Study parameters considered as 'in-vitro' markers of VWF 'functionality' or potential clinical efficacy (i.e. VWF:CB and VWF:RCo relative to VWF:Ag, level of HMW VWF relative to LMW-VWF) were determined to be higher for Biostate than AHF (High Purity). PFA-100 CTs did not adequately reflect changes in these VWF parameters. Based on these results, one would expect Biostate to be at least as effective, if not superior to AHF (High Purity) for the treatment of VWD.

Impact of manufacturing improvements on clinical safety of albumin: Australian pharmacovigilance data for 1988-2005.

OBJECTIVE: To evaluate the impact of manufacturing improvements on the clinical safety of human albumin solutions in Australia. METHODS: This retrospective study examined the incidence of spontaneously reported post-market adverse drug reactions (ADRs) in Australia associated with successive generations of albumin products manufactured by the Bioplasma Division of CSL Limited (CSL Bioplasma) over 18 years (1988-2005). Key characteristics of each product generation which could affect clinical safety, such as purity, aggregates and prekallikrein activator (PKA) levels, were also identified from CSL batch release records. RESULTS: A total of 3.7 million bottles of iso-oncotic and hyperoncotic albumin products were distributed in Australia over the period. Improvements to manufacturing processes resulted in products with increased albumin purity, lower levels of impurities such as aggregates and PKA, and reduced batch-to-batch variation. The total ADR incidence (number of ADRs per 100 000 bottles distributed) associated with the products currently supplied was 1.5 and 1.7 for Albumex 4 (2VI) and Albumex 20 (2VI), respectively. This was a significant reduction compared with the earlier generation products Stable Plasma Protein Solution (14.1) and 20% Normal Serum Albumin (11.5), respectively (P<0.0001). In particular, hypotensive reactions declined substantially. CONCLUSION: Post-market pharmacovigilance data collected for successive generations of human albumin products supplied in Australia over 18 years indicates that manufacturing improvements have significantly improved the clinical safety profile of this product.

Phase 1 study of HPV16-specific immunotherapy with E6E7 fusion protein and ISCOMATRIX adjuvant in women with cervical intraepithelial neoplasia.

PURPOSE: Persistent infection of cervical epithelium with "high risk" human papillomavirus (HPV) results in cervical intraepithelial neoplasia (CIN) from which squamous cancer of the cervix can arise. A study was undertaken to evaluate the safety and immunogenicity of an HPV16 immunotherapeutic consisting of a mixture of HPV16 E6E7 fusion protein and ISCOMATRIX adjuvant (HPV16 Immunotherapeutic) for patients with CIN. EXPERIMENTAL DESIGN: Patients with CIN (n = 31) were recruited to a randomised blinded placebo controlled dose ranging study of immunotherapy. RESULTS: Immunotherapy was well tolerated. Immunised subjects developed HPV16 E6E7 specific immunity. Antibody, delayed type hypersensitivity, in vitro cytokine release, and CD8 T cell responses to E6 and E7 proteins were each significantly greater in the immunised subjects than in placebo recipients. Loss of HPV16 DNA from the cervix was observed in some vaccine and placebo recipients. CONCLUSIONS: The HPV16 Immunotherapeutic comprising HPV16E6E7 fusion protein and ISCOMATRIX adjuvant is safe and induces vaccine antigen specific cell mediated immunity.

Recombinant NY-ESO-1 protein with ISCOMATRIX adjuvant induces broad integrated antibody and CD4(+) and CD8(+) T cell responses in humans.

NY-ESO-1 is a "cancer-testis" antigen expressed in many cancers. ISCOMATRIX is a saponin-based adjuvant that induces antibody and T cell responses. We performed a placebo-controlled clinical trial evaluating the safety and immunogenicity of recombinant NY-ESO-1 protein with ISCOMATRIX adjuvant. Forty-six evaluable patients with resected NY-ESO-1-positive tumors received three doses of vaccine intramuscularly at monthly intervals. The vaccine was well tolerated. We observed high-titer antibody responses, strong delayed-type hypersensitivity reactions, and circulating CD8(+) and CD4(+) T cells specific for a broad range of NY-ESO-1 epitopes, including known and previously unknown epitopes. In an unplanned analysis, vaccinated patients appeared to have superior clinical outcomes to those treated with placebo or protein alone. The vaccine is safe and highly potent immunologically.