Pathogen safety of human C1 esterase inhibitor concentrate

Safety profile of plasma for fractionation donated in the United Kingdom, with respect to variant Creutzfeldt-Jakob disease

Plasma-derived medicinal products (PDMPs) are life-saving and life-improving therapies, but the raw material is in short supply: Europe depends on importation from countries including the United States. Plasma from donors resident in the United Kingdom has not been fractionated since 1999 when a precautionary measure was introduced in response to the outbreak of variant Creutzfeldt-Jakob disease (vCJD). Cases of vCJD have been far fewer than originally predicted in the 1990s. Since the introduction of leucodepletion in 1999, and accounting for the incubation period, more than 40 million UK-derived blood components have been issued with no reports of TT vCJD. In February 2021, the UK Government authorized manufacture of immunoglobulin from UK plasma. Following separate reviews concluding no significant difference in the risk posed, the United States, Australia, Ireland and Hong Kong also lifted their deferrals of blood donors with a history of living in the United Kingdom. Other countries are actively reviewing their position. Demand is rising for PDMPs, and Europe faces a threat of supply shortages. Industry and patient groups are clear that using UK plasma would bring significant immediate benefits to patients and to the resilience of the European supply chain. From this scientific review, we conclude that UK plasma is safe for fractionation and urge blood regulators and operators to take account of this safety profile when considering fractionation of UK plasma, and to revise their guidelines on the deferral of donors who have lived in, or received a transfusion in, the United Kingdom.

The international WAO/EAACI guideline for the management of hereditary angioedema - The 2021 revision and update

Hereditary Angioedema (HAE) is a rare and disabling disease for which early diagnosis and effective therapy are critical. This revision and update of the global WAO/EAACI guideline on the diagnosis and management of HAE provides up-to-date guidance for the management of HAE. For this update and revision of the guideline, an international panel of experts reviewed the existing evidence, developed 28 recommendations, and established consensus by an online DELPHI process. The goal of these recommendations and guideline is to help physicians and their patients in making rational decisions in the management of HAE with deficient C1-inhibitor (type 1) and HAE with dysfunctional C1-inhibitor (type 2), by providing guidance on common and important clinical issues, such as: 1) How should HAE be diagnosed? 2) When should HAE patients receive prophylactic on top of on-demand treatment and what treatments should be used? 3) What are the goals of treatment? 4) Should HAE management be different for special HAE patient groups such as children or pregnant/breast feeding women? 5) How should HAE patients monitor their disease activity, impact, and control? It is also the intention of this guideline to help establish global standards for the management of HAE and to encourage and facilitate the use of recommended diagnostics and therapies for all patients.

The international WAO/EAACI guideline for the management of hereditary angioedema-The 2021 revision and update

Hereditary angioedema (HAE) is a rare and disabling disease for which early diagnosis and effective therapy are critical. This revision and update of the global WAO/EAACI guideline on the diagnosis and management of HAE provides up-to-date guidance for the management of HAE. For this update and revision of the guideline, an international panel of experts reviewed the existing evidence, developed 28 recommendations, and established consensus by an online DELPHI process. The goal of these recommendations and guideline is to help physicians and their patients in making rational decisions in the management of HAE with deficient C1 inhibitor (type 1) and HAE with dysfunctional C1 inhibitor (type 2), by providing guidance on common and important clinical issues, such as: (1) How should HAE be diagnosed? (2) When should HAE patients receive prophylactic on top of on-demand treatment and what treatments should be used? (3) What are the goals of treatment? (4) Should HAE management be different for special HAE patient groups such as children or pregnant/breast-feeding women? and (5) How should HAE patients monitor their disease activity, impact, and control? It is also the intention of this guideline to help establish global standards for the management of HAE and to encourage and facilitate the use of recommended diagnostics and therapies for all patients.

C1-Inhibitor: Structure, Functional Diversity and Therapeutic Development

Human C1-Inhibitor (C1INH), also known as C1-esterase inhibitor, is an important multifunctional plasma glycoprotein that is uniquely involved in a regulatory network of complement, contact, coagulation, and fibrinolytic systems. C1INH belongs to a superfamily of serine proteinase inhibitor (serpins) and exhibits its inhibitory activities towards several target proteases of plasmatic cascades, operating as a major anti-inflammatory protein in the circulation. In addition to its inhibitory activities, C1INH is also involved in non-inhibitory interactions with some endogenous proteins, polyanions, cells and infectious agents. While C1INH is essential for multiple physiological processes, it is better known for its deficiency with regards to Hereditary Angioedema (HAE), a rare autosomal dominant disease clinically manifested by recurrent acute attacks of increased vascular permeability and edema. Since the link was first established between functional C1INH deficiency in plasma and HAE in the 1960s, tremendous progress has been made in the biochemical characterization of C1INH and its therapeutic development for replacement therapies in patients with C1INH-dependent HAE. Various C1INH biological activities, recent advances in the HAE-targeted therapies, and availability of C1INH commercial products have prompted intensive investigation of the C1INH potential for treatment of clinical conditions other than HAE. This article provides an updated overview of the structure and biological activities of C1INH, its role in HAE pathogenesis, and recent advances in the research and therapeutic development of C1INH; it also considers some trends for using C1INH therapeutic preparations for applications other than angioedema, from sepsis and endotoxin shock to severe thrombotic complications in COVID-19 patients.

Nanofiltration as a robust method contributing to viral safety of plasma-derived therapeutics: 20 years' experience of the plasma protein manufacturers

BACKGROUND

Nanofiltration entails the filtering of protein solutions through membranes with pores of nanometric sizes that have the capability to effectively retain a wide range of viruses.

STUDY DESIGN AND METHODS

Data were collected from 754 virus validation studies (individual data points) by Plasma Protein Therapeutics Association member companies and analyzed for the capacity of a range of nanofilters to remove viruses with different physicochemical properties and sizes. Different plasma product intermediates were spiked with viruses and filtered through nanofilters with different pore sizes using either tangential or dead-end mode under constant pressure or constant flow. Filtration was performed according to validated scaled-down laboratory conditions reflecting manufacturing processes. Effectiveness of viral removal was assessed using cell culture infectivity assays or polymerase chain reaction (PCR).

RESULTS

The nanofiltration process demonstrated a high efficacy and robustness for virus removal. The main factors affecting nanofiltration efficacy are nanofilter pore size and virus size. The capacity of nanofilters to remove smaller, nonenveloped viruses was dependent on filter pore size and whether the nanofiltration process was integrated and designed with the intention to provide effective parvovirus retention. Volume filtered, operating pressure, and total protein concentration did not have a significant impact on the effectiveness of virus removal capacity within the investigated ranges.

CONCLUSIONS

The largest and most diverse nanofiltration data collection to date substantiates the effectiveness and robustness of nanofiltration in virus removal under manufacturing conditions of different plasma-derived proteins. Nanofiltration can enhance product safety by providing very high removal capacity of viruses including small non-enveloped viruses.

Polysaccharide-based chromatographic adsorbents for virus purification and viral clearance

Viruses still pose a significant threat to human and animal health worldwide. In the fight against viral infections, high-purity viral stocks are needed for manufacture of safer vaccines. It is also a priority to ensure the viral safety of biopharmaceuticals such as blood products. Chromatography techniques are widely implemented at both academic and industrial levels in the purification of viral particles, whole viruses and virus-like particles to remove viral contaminants from biopharmaceutical products. This paper focuses on polysaccharide adsorbents, particulate resins and membrane adsorbers, used in virus purification/removal chromatography processes. Different chromatographic modes are surveyed, with particular attention to ion exchange and affinity/pseudo-affinity adsorbents among which commercially available agarose-based resins (Sepharose®) and cellulose-based membrane adsorbers (Sartobind®) occupy a dominant position. Mainly built on the development of new ligands coupled to conventional agarose/cellulose matrices, the development perspectives of polysaccharide-based chromatography media in this antiviral area are stressed in the conclusive part.

[Angioedema prophylaxis]

Angioedema is a spontaneous, edematous swelling of the deep layers of the skin or mucous membrane. Angioedema in the respiratory tract is potentially life-threatening. The classification of angioedema into mast-cell-mediated (e. g. urticaria) or bradykinin-mediated (e. g. hereditary angioedema) is important for correct and rational treatment. Generally, two therapeutic strategies are available for angioedema treatment. On-demand treatment of angioedema symptoms that already have emerged aims to stop the further development of the attack and, thus, limits the severity and duration of the attack. This strategy is well established in the treatment of patients with hereditary angioedema, whereas in chronic spontaneous urticaria on-demand therapy plays no role in the guideline recommendations. In contrast, the therapeutic strategy of prophylaxis aims to prevent the occurrence of spontaneous and induced attacks as far as possible. Prophylaxis is the sole therapy strategy for chronic urticaria and is applied at all stages of the treatment algorithm. In the case of hereditary angioedema, on-demand therapy can be complemented by prophylaxis after careful and individual indication. In hereditary angioedema, prophylaxis is currently gaining in importance due to improved treatment options. Patients who use a prophylactic regime are much less likely to be forced to wait for the unpredictable occurrence of an attack and then to react with an on-demand treatment. Prophylactic treatment takes place at times determined by the patient himself, in contrast to treatment on an as-needed basis. The loss of unpredictability is a decisive moment in improving the quality of life.

The international WAO/EAACI guideline for the management of hereditary angioedema-The 2017 revision and update

Hereditary Angioedema (HAE) is a rare and disabling disease. Early diagnosis and appropriate therapy are essential. This update and revision of the global guideline for HAE provides up-to-date consensus recommendations for the management of HAE. In the development of this update and revision of the guideline, an international expert panel reviewed the existing evidence and developed 20 recommendations that were discussed, finalized and consented during the guideline consensus conference in June 2016 in Vienna. The final version of this update and revision of the guideline incorporates the contributions of a board of expert reviewers and the endorsing societies. The goal of this guideline update and revision is to provide clinicians and their patients with guidance that will assist them in making rational decisions in the management of HAE with deficient C1-inhibitor (type 1) and HAE with dysfunctional C1-inhibitor (type 2). The key clinical questions covered by these recommendations are: (1) How should HAE-1/2 be defined and classified?, (2) How should HAE-1/2 be diagnosed?, (3) Should HAE-1/2 patients receive prophylactic and/or on-demand treatment and what treatment options should be used?, (4) Should HAE-1/2 management be different for special HAE-1/2 patient groups such as pregnant/lactating women or children?, and (5) Should HAE-1/2 management incorporate self-administration of therapies and patient support measures?

Optimum Use of Acute Treatments for Hereditary Angioedema: Evidence-Based Expert Consensus

Acute treatment of hereditary angioedema due to C1 inhibitor deficiency has become available in the last 10 years and has greatly improved patients’ quality of life. Two plasma-derived C1 inhibitors (Berinert and Cinryze), a recombinant C1 inhibitor (Ruconest/Conestat alpha), a kallikrein inhibitor (Ecallantide), and a bradykinin B2 receptor inhibitor (Icatibant) are all effective. Durably good response is maintained over repeated treatments and several years. All currently available prophylactic agents are associated with breakthrough attacks, therefore an acute treatment plan is essential for every patient. Experience has shown that higher doses of C1 inhibitor than previously recommended may be desirable, although only recombinant C1 inhibitor has been subject to full dose–response evaluation. Treatment of early symptoms of an attack, with any licensed therapy, results in milder symptoms, more rapid resolution and shorter duration of attack, compared with later treatment. All therapies have been shown to be well-tolerated, with low risk of serious adverse events. Plasma-derived C1 inhibitors have a reassuring safety record regarding lack of transmission of virus or other infection. Thrombosis has been reported in association with plasma-derived C1 inhibitor in some case series. Ruconest was associated with anaphylaxis in a single rabbit-allergic volunteer, but no further anaphylaxis has been reported in those not allergic to rabbits despite, in a few cases, prior IgE sensitization to rabbit or milk protein. Icatibant is associated with high incidence of local reactions but not with systemic effects. Ecallantide may cause anaphylactoid reactions and is given under supervision. For children and pregnant women, plasma-derived C1 inhibitor has the best evidence of safety and currently remains first-line treatment.

Cellulose-based virus-retentive filters: a review

Viral filtration is a critical step in the purification of biologics and in the monitoring of microbiological water quality. Viral filters are also essential protection elements against airborne viral particles. The present review first focuses on cellulose-based filter media currently used for size-exclusion and/or adsorptive filtration of viruses from biopharmaceutical and environmental water samples. Data from spiking studies quantifying the viral filtration performance of cellulosic filters are detailed, i.e., first, the virus reduction capacity of regenerated cellulose hollow fiber filters in the manufacturing process of blood products and, second, the efficiency of virus recovery/concentration from water samples by the viradel (virus adsorption-elution) method using charge modified, electropositive cellulosic filters or conventional electronegative cellulose ester microfilters. Viral analysis of field water samples by the viradel technique is also surveyed. This review then describes cellulose-based filter media used in individual protection equipment against airborne viral pathogens, presenting innovative filtration media with virucidal properties. Some pros and cons of cellulosic viral filters and perspectives for cellulose-based materials in viral filtration are underlined in the review.

Pathogen safety and characterisation of a highly purified human alpha1-proteinase inhibitor preparation

Alpha₁-proteinase inhibitor (A₁PI) deficiency is a genetic condition predisposing to emphysema. Respreeza/Zemaira, a therapeutic preparation of A₁PI, is prepared from human plasma. This article describes the purity and stability of Respreeza/Zemaira and the capacity of virus and prion reduction steps incorporated into its manufacturing process. Purity and stability of Respreeza/Zemaira were analysed using established methods. To test pathogen clearance capacity, high levels of test viruses/prions were spiked into aliquots of production intermediates and clearance studies were performed for selected manufacturing steps, under production and robustness conditions, using validated scale-down models. Respreeza/Zemaira had a purity of 99% A₁PI and consisted of 96% monomers. It remained stable after storage for 3 years at 25 °C. Specific activity was 0.895 mg active A₁PI/mg protein. Pasteurisation inactivated enveloped viruses and the non-enveloped hepatitis A virus. 20 N/20 N virus filtration was highly effective and robust at removing all tested viruses, including parvoviruses, to below the limit of detection. Cold ethanol fractionation provided substantial reduction of prions. The manufacturing process of Respreeza/Zemaira ensures the production of a stable and pure product. Taking into consideration the donor selection process, the testing of donations, and the highly effective virus and prion reduction, Respreeza/Zemaira has a high safety margin.

Inactivation of viruses by pasteurization at 60 °C for 10 h with and without 40% glucose as stabilizer during a new manufacturing process of α2-Macroglobulin from Cohn Fraction IV

Pasteurization is regularly used to inactivate viruses for the safety of plasma derivatives. Influence of pasteurization at 60 °C for 10 h on α2-Macroglobulin activity and virus inactivation were studied. With 40% sugar as stabilizers more than 70% α2-Macroglobulin activity was reserved after pasteurization compared with 20% in control. Glucose presented a better activity protection effect than sucrose and maltose. By pasteurization without stabilizer the virus titers of pseudorabies virus, Sindbis virus, porcine parvovirus and encephalomyocarditis virus were reduced more than 5.88 log₁₀, 7.50 log₁₀, 4.88 log₁₀, and 5.63 log₁₀ respectively within 2 h. By pasteurization with 40% glucose vesicular stomatitis virus was inactivated more than 5.88 log₁₀ within 1 h. Only 2.71 log₁₀ reduction was achieved for encephalomyocarditis virus after 10 h. 40% glucose protected α2-M activity and viruses simultaneously from pasteurization. Other viral inactivation methods need to be incorporated to ensure viral safety of this manufacturing process of α2-Macroglobulin.

Pathogen safety of a pasteurized four-factor human prothrombin complex concentrate preparation using serial 20N virus filtration

BACKGROUND

Beriplex P/N/Kcentra/Coaplex/Confidex is a four-factor human prothrombin complex concentrate (PCC). Here, we describe the pathogen safety profile and biochemical characteristics of an improved manufacturing process that further enhances the virus safety of Beriplex P/N.

STUDY DESIGN AND METHODS

Samples of product intermediates were spiked with test viruses, and prions were evaluated under routine production and robustness conditions of the scale-down version of the commercial manufacturing process for their capacity to inactivate or remove pathogens. The PCC was characterized by determining the activity of Factor (F)II, FVII, FIX, FX, protein C, and protein S and the concentration of heparin and antithrombin III in nine product lots.

RESULTS

The manufacturing process had a very high virus reduction capacity for a broad variety of virus challenges (overall reduction factors ≥15.5 to ≥18.4 log for enveloped viruses and 11.5 to ≥11.9 log for nonenveloped viruses). The high virus clearance capacity was provided by two dedicated virus reduction steps (pasteurization and serial 20N virus filtration) that provided effective inactivation and removal of viruses and a purification step (ammonium sulfate precipitation and adsorption to calcium phosphate) that contributed to the overall virus removal capacity. The diethylaminoethyl (DEAE) chromatography and ammonium sulfate precipitation steps removed prions to below the limit of detection. The levels of different clotting factors in the final product were well balanced.

CONCLUSION

The improved manufacturing process of Beriplex P/N further enhances the margin of pathogen safety based on its capacity to remove and inactivate a wide range of virus challenges.

Diagnostic and therapeutic management of hereditary angioedema due to C1-inhibitor deficiency: the Italian experience

PURPOSE OF REVIEW

Hereditary angioedema (HAE) due to C1-inhibitor (C1-INH) deficiency (C1-INH-HAE) is a rare disease, with a reported prevalence of about 1 : 50 000. C1-INH-HAE causes disabling symptoms, which may be life-threatening if swelling affects upper airways. Diagnostic procedures are now well established and the role of bradykinin as the main mediator of plasma outflow eliciting angioedema formation has been clearly elucidated.

RECENT FINDINGS

Increased understanding of the pathogenesis of C1-INH-HAE allowed in recent years the development of new drugs targeted to inhibit bradykinin synthesis (Ecallantide) or activity (Icatibant). At the same time, a recombinant C1-INH concentrate (Ruconest) was produced from the milk of transgenic rabbits and two plasma-derived C1-INHs (Berinert, Cinryze) underwent controlled trials to obtain marketing authorization. In 2012, an Italian network for C1-INH-HAE (ITACA) was established by physicians of 17 HAE reference centres to collect data from Italian patients and to homogenize and improve the diagnostic and therapeutic approach to the disease.

SUMMARY

Although there is a widespread agreement on therapeutic goals and treatment of C1-INH-HAE acute attacks, different approaches to prophylaxis are still present among HAE experts. The clinical experience of ITACA on a large population of C1-INH-HAE patients followed for several years may help in identifying the most effective strategies for the management of the disease.

The safety of treatments for angioedema with hereditary C1 inhibitor deficiency

INTRODUCTION

Angioedema is a localized and self-limiting edema of the subcutaneous and submucosal tissue. Hereditary angioedema with C1 inhibitor deficiency (C1-INH-HAE) is the best characterized form of hereditary angioedema. In C1-INH-HAE, the reduced plasma levels of C1-INH cause instability of the contact system with release of bradykinin, the key mediator of angioedema. C1-INH-HAE is characterized by recurrent skin swelling, abdominal pain, and potentially life-threatening upper airways obstruction. Knowledge of the molecular mechanisms leading from C1-INH deficiency to angioedema allowed the development of several therapies.

AREAS COVERED

The aim of this review article is to discuss the safety of currently available treatments of C1-INH-HAE. The authors give an insight on the mechanism of action and safety profile of drugs for treatment of acute attacks and for short- and long-term prophylaxis. Evidence from systematic reviews, clinical trials, retrospective studies, and case reports is summarized in this review.

EXPERT OPINION

C1-INH-HAE is a disabling, life-threatening condition that lasts life-long. Different therapeutic approaches with different drugs provide significant benefit to patients. Safety profiles of these therapies are critical for optimal therapeutic decision and need to be known by C1-INH-HAE treating physicians for appropriate risk/benefit evaluation.

Biochemical comparison of four commercially available C1 esterase inhibitor concentrates for treatment of hereditary angioedema

Background

For safe and efficacious treatment of hereditary angioedema, C1 esterase inhibitor (C1-INH) concentrates should have high purity and high amounts of functional protein. As no pharmacopoeia requirements exist for C1-INH concentrate lot release, biochemical characteristics as declared by the manufacturers may not be compared directly. This study compared the characteristics and purity profiles of four commercially available C1-INH concentrates.

Study Design and Methods

The analysis included one transgenic (Ruconest) and three plasma-derived (Berinert, Cetor, Cinryze) C1-INH concentrates. C1-INH antigen concentration was determined by nephelometry, total protein (specific activity) with a Bradford assay, purity by size-exclusion chromatography and gel electrophoresis, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was performed.

Results

Functionality (inversely proportional to antigen-to-activity ratio) was lowest for Ruconest (1.67), followed by Cetor (1.42), Berinert (1.24), and Cinryze (1.22). Specific activity (U/mg) and purity (%) were highest in Ruconest (12.13; 98.6) and Berinert (11.57; 97.0), followed by Cinryze (10.41; 89.5) and Cetor (9.01; 88.6). Main protein bands were found for all plasma-derived products at approximately 105 kDa, and for Ruconest, at approximately 98 kDa. Additional bands in the plasma-derived products were α1-antichymotrypsin, ceruloplasmin, Factor C3 (Cinryze/Cetor), and immunoglobulin heavy constant mu (Berinert).

Conclusion

Ruconest has a very high purity profile but is not identical to the human C1-INH protein. Of the plasma-derived products, Berinert has the highest purity profile. The impact of the nontherapeutic proteins identified has not yet been evaluated. For harmonization of the analysis for drug release, we recommend the establishment of regulatory requirements for purity determination and the implementation of threshold levels in C1-INH concentrates.

WAO Guideline for the Management of Hereditary Angioedema

Hereditary Angioedema (HAE) is a rare disease and for this reason proper diagnosis and appropriate therapy are often unknown or not available for physicians and other health care providers. For this reason we convened a group of specialists that focus upon HAE from around the world to develop not only a consensus on diagnosis and management of HAE, but to also provide evidence based grades, strength of evidence and classification for the consensus. Since both consensus and evidence grading were adhered to the document meets criteria as a guideline. The outcome of the guideline is to improve diagnosis and management of patients with HAE throughout the world and to help initiate uniform care and availability of therapies to all with the diagnosis no matter where the residence of the individual with HAE exists.