Immunogenicity of therapeutic proteins. Part 3: Impact of manufacturing changes

Induction of heat shock protein expression in SP2/0 transgenic cells and its effect on the production of monoclonal antibodies

The objective of the current investigation was to evaluate the induction of heat shock proteins (HSPs) in SP2/0 transgenic cells and the effect of these proteins on the production of monoclonal antibodies (mAbs). The SP2/0 cell line expressing the PSG-026 antibody, a biosimilar candidate of golimumab, the culture parameters, and the target protein expression were not justified for industrial production and were used for the experiments. Paracetamol and heat shock were used as chemical and physical inducers of HSPs, respectively. The results showed that paracetamol and heat shock increased the expression of HSP70 and HSP27 at the mRNA and protein levels. The expression of HSPs was greater in paracetamol-treated cells than in heat shock-treated cells. Paracetamol treatment at concentrations above 0.5 mM significantly reduced cell viability and mAb expression. However, treatment with 0.25 mM paracetamol results in delayed cell death and increased mAb production. Heat shock treatment at 45°C for 30 minutes after enhanced mAb expression was applied after pre-treatment with paracetamol. In bioreactor cultures, pretreatment of cells with paracetamol improved cell viability and shortened the lag phase, resulting in increased cell density. The production of mAbs in paracetamol-treated cultures was markedly greater than that in the control. Analysis of protein quality and charge variants revealed no significant differences between paracetamol-treated and control cultures, indicating that the induction of HSPs did not affect protein aggregation or charge variants. These findings suggest that inducing and manipulating HSP expression can be a valuable strategy for improving recombinant protein production in biopharmaceutical processes.

The FDA's New Guideline "Generally Accepted Scientific Knowledge" (GASK): An Opportunity to Expedite the Approval of Biosimilars

The US FDA's new guideline suggests using "Generally Accepted Science Knowledge" (GASK) to develop nonclinical testing protocols for developing drugs and biologicals to remove unnecessary testing. Interpreting acceptable scientific knowledge as a rational approach has motivated the author to suggest substantial changes to the development of biosimilars, as demonstrated in this paper. The FDA can accept these suggestions without requiring any legislative change to the Act that defines such requirements. Suggested here is the waiving of clinical efficacy testing due to its lower sensitivity compared to analytical and functional testing and pharmacokinetic profiling. Also questioned is the need to test pharmacodynamic markers that do not correlate with clinical response and find new biomarkers requiring extensive testing to validate their use. Should the FDA accept these scientifically rational suggestions, it will significantly reduce the time and cost of approving biosimilars without safety or efficacy risk, as justified based on acceptable scientific knowledge and rationality.

Integrated summary of immunogenicity of polatuzumab vedotin in patients with relapsed or refractory B-cell non-Hodgkin’s lymphoma

Polatuzumab vedotin, marketed under the trade name POLIVY®, is a CD79b-targeted antibody-drug conjugate that preferentially delivers a potent anti-mitotic agent (monomethyl auristatin E) to B cells, resulting in anti-cancer activity against B-cell malignancies. In 2019, polatuzumab vedotin in combination with rituximab and bendamustine was approved by the United States Food and Drug Administration for the treatment of adult patients with diffuse large B-cell lymphoma who have received at least two prior therapies. Recent Health Authority guidance recommendations for submitting an Integrated Summary of Immunogenicity were followed including a comprehensive immunogenicity risk assessment, bioanalytical strategy, and immunogenicity data to support the registration of polatuzumab vedotin. Key components of the polatuzumab vedotin Integrated Summary of Immunogenicity and data are presented. Validated semi-homogeneous bridging enzyme-linked immunosorbent assays were used to detect anti-drug antibodies (ADA) to polatuzumab vedotin and characterize the immune response in patients with non-Hodgkin’s lymphoma. The overall incidence of ADA observed for polatuzumab vedotin was low across seven clinical trials. The low incidence of ADA is likely due to the mechanism of action of polatuzumab vedotin that involves targeting and killing of B cells, thereby limiting the development to plasma cells and ADA secretion. Furthermore, patients are co-medicated with rituximab, which also targets B cells and results in B-cell depletion. Therefore, the immunogenicity risk is considered low and not expected to impact the polatuzumab vedotin benefit/risk profile.

Large-Scale Postmarketing Surveillance of Biological Drugs for Immune-Mediated Inflammatory Diseases Through an Italian Distributed Multi-Database Healthcare Network: The VALORE Project

BACKGROUND

Biological drugs have improved the management of immune-mediated inflammatory diseases (IMIDs) despite being associated with important safety issues such as immunogenicity, infections, and malignancies in real-world settings.

OBJECTIVE

The aim of this study was to explore the potential of a large Italian multi-database distributed network for use in the postmarketing surveillance of biological drugs, including biosimilars, in patients with IMID.

METHODS

A retrospective cohort study was conducted using 13 Italian regional claims databases during 2010-2019. A tailor-made R-based tool developed for distributed analysis of claims data using a study-specific common data model was customized for this study. We measured the yearly prevalence of biological drug users and the frequency of switches between originator and biosimilars for infliximab, etanercept, and adalimumab separately and stratified them by calendar year and region. We then calculated the cumulative number of users and person-years (PYs) of exposure to individual biological drugs approved for IMIDs. For a number of safety outcomes (e.g., severe acute respiratory syndrome coronavirus 2 [SARS-COV-2] infection), we conducted a sample power calculation to estimate the PYs of exposure required to investigate their association with individual biological drugs approved for IMIDs, considering different strengths of association.

RESULTS

From a total underlying population of almost 50 million inhabitants from 13 Italian regions, we identified 143,602 (0.3%) biological drug users, with a cumulative exposure of 507,745 PYs during the entire follow-up. The mean age ± standard deviation of biological drug users was 49.3 ± 16.3, with a female-to-male ratio of 1.2. The age-adjusted yearly prevalence of biological drug users increased threefold from 0.7 per 1000 in 2010 to 2.1 per 1000 in 2019. Overall, we identified 40,996 users of biosimilars of tumor necrosis factor (TNF)-α inhibitors (i.e., etanercept, adalimumab, and infliximab) in the years 2015-2019. Of these, 46% (N = 18,845) switched at any time between originator and biosimilars or vice versa. To investigate a moderate association (incidence rate ratio 2) between biological drugs approved for IMIDs and safety events of interest, such as optic neuritis (lowest background incidence rate 10.4/100,000 PYs) or severe infection (highest background incidence rate 4312/100,000 PYs), a total of 43,311 PYs and 104 PYs of exposure to individual biological drugs, respectively, would be required. As such, using this network, of 15 individual biological drugs approved for IMIDs, the association with those adverse events could be investigated for four (27%) and 14 (93%), respectively.

CONCLUSION

The VALORE project multi-database network has access to data on more than 140,000 biological drug users (and > 0.5 million PYs) from 13 Italian regions during the years 2010-2019, which will be further expanded with the inclusion of data from other regions and more recent calendar years. Overall, the cumulated amount of person-time of exposure to biological drugs approved for IMIDs provides enough statistical power to investigate weak/moderate associations of almost all individual compounds and the most relevant safety outcomes. Moreover, this network may offer the opportunity to investigate the interchangeability of originator and biosimilars of several TNFα inhibitors in different therapeutic areas in real-world settings.

Factors affecting the quality of therapeutic proteins in recombinant Chinese hamster ovary cell culture

Chinese hamster ovary (CHO) cells are the most widely used mammalian host cells for the commercial production of therapeutic proteins. Fed-batch culture is widely used to produce therapeutic proteins, including monoclonal antibodies, because of its operational simplicity and high product titer. Despite technical advances in the development of culture media and cell cultures, it is still challenging to maintain high productivity in fed-batch cultures while also ensuring good product quality. In this review, factors that affect the quality attributes of therapeutic proteins in recombinant CHO (rCHO) cell culture, such as glycosylation, charge variation, aggregation, and degradation, are summarized and categorized into three groups: culture environments, chemical additives, and host cell proteins accumulated in culture supernatants. Understanding the factors that influence the therapeutic protein quality in rCHO cell culture will facilitate the development of large-scale, high-yield fed-batch culture processes for the production of high-quality therapeutic proteins.

Biosimilars accessible in the market for the treatment of cancer

Biosimilars are the biological product clinically identical to a biologic reference standard regarding their strength, purity, and safety. A large segment of biosimilars has been developed for the treatment of cancer. This review aims to discuss various facets of biosimilars and explicates on biosimilars accessible in the market for cancer clinical intervention. It also illustrates the outcomes of recent clinical trial studies concerning biosimilars. Further, it also crosstalk the safety profiles, regulatory approval requirements, and allied challenges therein. The work will be of significant interest to researchers working in the field of biologics and biosimilars.

Regulatory density as a means to refine current regulatory approaches for increasingly complex medicines

The continuous scientific, societal, and technological advancements have shifted drug development toward increasingly complex and ever more targeted treatments. This creates new and unprecedented challenges for global regulatory systems. To address the increased risks and uncertainties of increasingly complex medicine, we advocate for a more tailored and flexible regulatory approach, which is explained here with the concept of 'regulatory density'. In the context of this paper, 'regulatory density' describes the relative amount of obligatory standards, measures and procedures applied to certain medicinal products or product classes and the resources required to meet these requirements. Given that risk and uncertainty are dynamic variables that can change over time, with this paper, we want to stimulate (re)thinking of regulatory approaches for managing the challenges of future complex medicines.

Biologics in Dermatology: Off-Label Indications

Skin and subcutaneous diseases affect millions of people worldwide, causing significant morbidity. Biologics are becoming increasingly useful for the treatment of many skin diseases, particularly as alternatives for patients who have failed to tolerate or respond to conventional systemic therapies. Biological therapies provide a targeted approach to treatment through interaction with specific components of the underlying immune and inflammatory disease processes. Advances in the understanding of disease pathophysiology for inflammatory skin diseases and in drug development have ushered in biologic therapies in dermatology. Biologic therapies are molecules that target specific proteins implicated in immune-mediated disease. This review article highlights the increasing evidence base for biologics in dermatology for off-label use.

The UK BIO-TRAC Study: A Cross-Sectional Study of Product and Batch Traceability for Biologics in Clinical Practice and Electronic Adverse Drug Reaction Reporting in the UK

Introduction

Due to the complexity of biologics and the inherent challenges for manufacturing, it is important to know the specific brand name and batch number of suspected biologics in adverse drug reaction (ADR) reports.

Objective

The aim of this study was to assess the extent to which biologics are traceable by brand name and batch number in UK hospital practice and in ADRs reported by patients and healthcare professionals.

Methods

We performed an online hospital pharmacist survey to capture information on how specific product details are recorded during the processes of prescribing, dispensing and administration of biologics in routine UK hospital practice. We also assessed the proportion of ADR reports specifying brand name and batch number from electronic ADR reports submitted to the UK national spontaneous reporting database, the Yellow Card Scheme, between 1 January 2009 and 30 September 2017.

Results

Brand name recording in routine hospital processes ranged from 79 to 91%, whereas batch numbers were less routinely recorded, ranging from 38 to 58%. Paper-based recording of product details was more commonly used for recording information. A total of 6108 electronic ADR reports were submitted to the Yellow Card Scheme for recombinant biologics, of which 38% and 15%, respectively, had an identifiable brand name and batch numbers. Whereas batch number traceability in electronic ADR reports improved slightly after the implementation of the European Union pharmacovigilance legislation in 2012, no improvement of brand name traceability was observed.

Conclusion

Brand name and batch number traceability for biologics in UK ADR reports are generally low. Shortcomings in the systematic recording of product details in UK clinical practice may contribute to the limited traceability.

Electronic supplementary material

The online version of this article (10.1007/s40264-019-00891-6) contains supplementary material, which is available to authorized users.

Automated High-Throughput Capillary Circular Dichroism and Intrinsic Fluorescence Spectroscopy for Rapid Determination of Protein Structure

Assessing the physical stability of proteins is one of the most important challenges in the development, manufacture, and formulation of biotherapeutics. Here, we describe a method for combining and automating circular dichroism and intrinsic protein fluorescence spectroscopy. By robotically injecting samples from a 96-well plate into an optically compliant capillary flow cell, complementary information about the secondary and tertiary structural state of a protein can be collected in an unattended manner from considerably reduced volumes of sample compared to conventional techniques. We demonstrate the accuracy and reproducibility of this method. Furthermore, we show how structural screening can be used to monitor unfolding of proteins in two case studies using (i) a chaotropic denaturant (urea) and (ii) low-pH buffers used for monoclonal antibody (mAb) purification during Protein A chromatography.

Safety of Biologics, Including Biosimilars: Perspectives on Current Status and Future Direction

In recent years, marketing of highly innovative and costly biologics improved the management of high-burden diseases such as autoimmune diseases, cancers, and chronic renal failure. Several widely prescribed biologics have recently lost or will shortly lose their patents, thus opening avenues to the marketing of a growing number of biosimilars worldwide, which are products similar in terms of quality, safety, and efficacy to already licensed reference products, thus allowing for potential savings in pharmaceutical expenditure. Numerous debates about the interchangeability between biosimilars and reference products are still ongoing, owing to concerns about potential immunogenicity raised by switching, which may cause a lack of effect and toxicity. Patients successfully treated with biologic therapy may theoretically receive biosimilars to contain costs, if reference product and related biosimilar are judged as interchangeable. However, the positions of regulatory agencies on the interchangeability and automatic substitution of biologics with biosimilars are very different. The benefit-risk profile of biosimilars has been often questioned by clinicians owing to the limited amount of pre-marketing information on clinical efficacy and safety, despite biosimilarity being based on a comparability exercise with the reference product to gain the biosimilar approval. Nevertheless, after more than 10 years of marketing from the first biosimilar approval in Europe, no proof of differences in terms of the safety profile of biosimilars and originators has been reported. In this context, post-marketing evaluation of both biologics and biosimilars safety profiles through analyses from spontaneous reporting databases and claims databases is crucial. An important issue for the pharmacovigilance of biologics concerns the traceability, indicating the brand name and batch number in spontaneous adverse drug reaction reports, but this requirement is not frequently addressed. This review aims to provide an overview of the characteristics and potential challenges in the safety profile assessment of biologics with a focus on the post-marketing setting.

Risk-Based Comparability Assessment for Monoclonal Antibodies During Drug Development: A Clinical Pharmacology Perspective

Due to complexities in the structure, function, and manufacturing process of antibody-based therapeutic proteins, comparability assessment for supporting manufacturing changes can sometimes be a challenging task. Regulatory guidance recommends a hierarchical risk-based approach, starting with Chemistry, Manufacturing, and Controls (CMC) analytical characterizations, followed by non-clinical and/or clinical studies to ensure that any potential changes in quality attributes have no adverse impact on efficacy and safety of the product. This review focuses on the changes in quality attributes which may potentially affect the pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of a monoclonal antibody (mAb) product, and provides general guidelines in designing non-clinical and clinical PK/PD studies to help support comparability assessments. A decision tree for comparability assessment is proposed depending on the nature of the changes in quality attributes, the potential impact of such changes, and the timing of the manufacturing change relative to the development process. Ideally, the optimization of manufacturing process should take place in the early stage of drug development (i.e., preclinical to phase 2a) as more stringent comparability criteria would have to be met if manufacturing changes occur in the late stage of drug development (i.e., phase 2b and after), and consequently, major changes in manufacturing process should be avoided during confirmatory phase 3 studies and post-approval of drug products.

Experience with host cell protein impurities in biopharmaceuticals

In the 40-year history of biopharmaceuticals, there have been a few cases where the final products contained residual host cell protein (HCP) impurities at levels high enough to be of concern. This article summarizes the industry experience in these cases where HCP impurities have been presented in public forums and/or published. Regulatory guidance on HCP impurities is limited to advising that products be as pure as practical, with no specified numerical limit because the risk associated with HCP exposure often depends on the clinical setting (route of administration, dose, indication, patient population) and the particular impurity. While the overall safety and purity track record of the industry is excellent, these examples illustrate several important lessons learned about the kinds of HCPs that co-purify with products (e.g., product homologs, and HCPs that react with product), and the kinds of clinical consequences of HCP impurities (e.g., direct biological activity, immunogenicity, adjuvant). The literature on industry experience with HCP impurities is scattered, and this review draws in to one reference documented examples where the data have been presented in meetings, patents, product inserts, or press releases, in addition to peer-reviewed journal articles. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:828-837, 2018.

Low Bioavailability and High Immunogenicity of a New Brand of E. colil-Asparaginase with Active Host Contaminating Proteins

The drug l-asparaginase is a cornerstone in the treatment of acute lymphoblastic leukemia (ALL). The native E. colil-asparaginase used in Brazil until recently has been manufactured by Medac/Kyowa. Then a decision was taken by the Ministry of Health in 2017 to supply the National Health System with a cheaper alternative l-asparaginase manufactured by Beijing SL Pharmaceutical, called Leuginase®. As opposed to Medac, the asparaginase that has been in use in Brazil under the trade name of Aginasa®, it was not possible to find a single entry with the terms Leuginase in the Pubmed repository. The apparent lack of clinical studies and the scarcity of safety information provided to the hospitals by the drug distributor created a debate among Brazilian pediatric oncologists about issues of safety and efficacy that culminated eventually in a court decision to halt the distribution of the new drug all over the country. Boldrini Children's Center, a non-profit pediatric oncohematology hospital, has conducted its own evaluation of Leuginase®. Mass spectrometry analyses found at least 12 different contaminating host-cell proteins (HCP) in Leuginase®. The presence of two HCP (beta-lactamase and malate dehydrogenase) was confirmed by orthogonal methodologies. The relative number of HCP peptides ranged from 19 to 37% of the total peptides identified by mass spectrometry. In vivo studies in mice injected with Leuginase® revealed a 3 times lower plasma bioavailability and the development of higher antibody titres against l-asparaginase in comparison to Aginasa®-injected animals. The decision to buy a new drug based on its price alone is not safe. Developing countries are especially vulnerable to cheaper alternatives that lack solid quality assurance.

Characterization of Aggregation Propensity of a Human Fc-Fusion Protein Therapeutic by Hydrogen/Deuterium Exchange Mass Spectrometry

Aggregation of protein therapeutics has long been a concern across different stages of manufacturing processes in the biopharmaceutical industry. It is often indicative of aberrant protein therapeutic higher-order structure. In this study, the aggregation propensity of a human Fc-fusion protein therapeutic was characterized. Hydrogen/deuterium exchange mass spectrometry (HDX-MS) was applied to examine the conformational dynamics of dimers collected from a bioreactor. HDX-MS data combined with spatial aggregation propensity calculations revealed a potential aggregation interface in the Fc domain. This study provides a general strategy for the characterization of the aggregation propensity of Fc-fusion proteins at the molecular level.Graphical Abstract.

Comparative study of idursulfase beta and idursulfase in vitro and in vivo

Hunter syndrome is an X-linked lysosomal storage disease caused by a deficiency in the enzyme iduronate-2-sulfatase (IDS), leading to the accumulation of glycosaminoglycans (GAGs). Two recombinant enzymes, idursulfase and idursulfase beta are currently available for enzyme replacement therapy for Hunter syndrome. These two enzymes exhibited some differences in various clinical parameters in a recent clinical trial. Regarding the similarities and differences of these enzymes, previous research has characterized their biochemical and physicochemical properties. We compared the in vitro and in vivo efficacy of the two enzymes on patient fibroblasts and mouse model. Two enzymes were taken up into the cell and degraded GAGs accumulated in fibroblasts. In vivo studies of two enzymes revealed similar organ distribution and decreased urinary GAGs excretion. Especially, idursulfase beta exhibited enhanced in vitro efficacy for the lower concentration of treatment, in vivo efficacy in the degradation of tissue GAGs and improvement of bones, and revealed lower anti-drug antibody formation. A biochemical analysis showed that both enzymes show largely a similar glycosylation pattern, but the several peaks were different and quantity of aggregates of idursulfase beta was lower.

Traceability of Biologics in The Netherlands: An Analysis of Information-Recording Systems in Clinical Practice and Spontaneous ADR Reports

Introduction and Objective

Pharmacovigilance requirements for biologics mandate that EU Member States shall ensure that any biologic that is the subject of a suspected adverse drug reaction (ADR) is identifiable by brand name and batch number. Recent studies showed that brand name identification is well established, whereas batch numbers are (still) poorly reported. We evaluated information-recording systems and practices in the Dutch hospital setting to identify determinants for brand name and batch number recording as well as success factors and bottlenecks for traceability.

Methods

We surveyed Dutch hospital pharmacists with an online questionnaire on systems and practices in hospitals for recording brand names and batch numbers. Additionally, we performed an analysis of the traceability of recombinant biologics in spontaneous ADR reports (received between 2009 and 2014) from the Netherlands Pharmacovigilance Centre Lareb.

Results

The survey showed that brand names are not routinely recorded in the clinical practice of Dutch hospitals, whereas batch numbers are poorly recorded. Seventy-six percent of the 1523 ADR reports for recombinant biologics had a traceable brand name whereas 5 % of these reports contained a batch number. The results suggest a possible relationship between the availability of brand and batch number information in clinical practice and the inclusion of this information in ADR reports for biologics.

Conclusion

The limited traceability of brand names and batch numbers in ADR reports may be primarily caused by the shortcomings in the recording of information in clinical practice. We recommend efforts to improve information-recording systems as a first step to improve the traceability of biologics in ADR reporting.

Electronic supplementary material

The online version of this article (doi:10.1007/s40264-015-0383-8) contains supplementary material, which is available to authorized users.

Molecular perspective of antibody aggregates and their adsorption on Protein A resin

Antibody aggregate is a common issue in therapeutic antibodies, which may compromise product efficacy and cause adverse effects. Antibody aggregate level is normally controlled in bioprocessing by polishing steps after Protein A capture. This paper studied the Higher Order Structures (HOS) of antibody aggregates (dimer H1 and H2) and their adsorption on Protein A resin and thus elucidated the mechanism using Protein A capture for enhanced aggregate removal. The HOS of antibody aggregates and their complex with Protein A were characterized using HDX-MS combined with SEC-MALS, Protein Conformational Array (PCA), and molecular modeling. The aggregate size and Protein A binding ratio suggested that H2 has much more compact structure than H1. HDX-MS and PCA further revealed that H1 was formed by single Fab-Fab interaction while H2 formed by Fab-Fab and likely Fc-Fc interaction. On Protein A resin, both the molar binding ratio and the correlation between protein size and ligand distance support that each monomer can only bind one Protein A ligand, while each dimer can bind two ligands, thus resulting in stronger resin binding. Furthermore, dimer H2 binds stronger than dimer H1 due to its compact structure. By integrating biophysical analysis and molecular modeling with process development, this study revealed the antibody aggregate structures and the mechanism of aggregate removal using Protein A chromatography. It also provided a general strategy for in-depth product and process understanding in antibody and other biologics development.

Functionalized micro-capillary film for the rapid at-line analysis of IgG aggregates in a cell culture bioreactor

A micro-capillary film has been developed that offers the potential for an at-line analytical tool for rapid aggregate analysis during biopharmaceutical antibody production. A non-porous walled micro-capillary film (NMCF) with cation exchange functionality was demonstrated to act as a chromatography medium that could be operated with high linear fluid velocities and was highly resistant to blockage by entrained particulates, including cells. The NMCF containing 19 parallel microcapillaries was prepared using a melt extrusion process from poly(ethylene-vinyl alcohol) copolymer (EVOH). The NMCF-EVOH was modified to have cation-exchange functionality (NMCF-EVOH-SP) and shown to differentially bind monomer and aggregated species of IgG antibody directly from a bioreactor. The use of NMCF-EVOH-SP to quantify aggregate concentrations in monoclonal antibody preparations in less than 20 minutes was demonstrated.

Biosimilar: what it is not

A biosimilar is a high quality biological medicine shown to be in essence the same as an original product. The European Medicines Agency (EMA) paved the way in the regulatory arena by creating a safeguarding framework for the development of biosimilars. Biosimilar is thus a regulatory term that alludes to the evidence-based studies required to demonstrate such very high similarity. They are therefore not innovative products but the pathway laid down by the EMA for their approval represented a new paradigm. This has brought some confusion and has cast doubts among healthcare professionals about the scientific evidence behind their authorization. Many papers have been published to clarify the concept, and to reassure those professionals, but misconceptions frequently still arise. Unfortunately, this prevents biosimilars from deploying their full therapeutic added value. This paper is intended to approach those misconceptions from a new angle, by explaining what a biosimilar is not…and why. A biosimilar is neither a generic, nor an original product. It is not a biobetter or a 'stand-alone'. Therefore, it should not be managed as such therapeutically, commercially or from a healthcare policy viewpoint. The EMA's criteria were acknowledged by other agencies, but a significant regulatory gap with a vast majority of regulatory bodies still remains. This leaves room for the so-called non-original biologics (NOB), i.e. non-biosimilar biologics, to be launched in many regions. Raising awareness of what a biosimilar is and what it is not, will generate trust in biosimilars among healthcare professionals and will ultimately benefit patients.

Developing oncology biosimilars: an essential approach for the future

The treatment of many diseases, particularly cancer, has been profoundly impacted by the introduction of biologic therapies (biologics), which are incorporated into the treatment algorithms of most oncology clinical practice guidelines. Biologics are large molecular weight, structurally complex proteins that are produced via complex manufacturing processes. With the patents of key biologics, including many widely used in oncology, set to expire in the near future, a number of pharmaceutical companies have focused on developing biosimilars. While the goal of development is to demonstrate that the biosimilar product is highly similar to the reference biologic product, biosimilars should not be viewed as "generic" biologics. Generic drugs are small chemical moieties that are identical to the patent-expired "reference" small-molecule drugs. It is not possible to produce an identical copy of a biologic, so the term "biosimilar" was chosen to define an appropriately similar biologic product. Improving patient access to cancer therapies such as biologics and reducing healthcare costs are key initiatives of the US Government; the integration of approved biosimilars into clinical practice will be instrumental in accomplishing these goals.

Preparing for Subsequent Entry Biologies in Dermatology and Rheumatology in Canada

Background:

Patents on several biologies will expire in Canada in the coming years. As they expire, applications to market subsequent entry biologies (SEBs) may be filed in Canada.

Objective:

To provide an understanding of the regulatory pathway and types of trials used for SEB authorization in Canada.

Methods:

Health Canada's draft guidance on SEBs was reviewed in regards to key issues and challenges in the development and authorization of SEBs.

Results:

Health Canada states that SEBs are not “generic biologies” and their authorization is not a declaration of pharmaceutical or therapeutic equivalence to the originator. The agency recommends that physicians make well-informed decisions regarding therapeutic interchange.

Conclusions:

Decisions on how to determine the place of SEBs in clinical practice for biologic-naive patients and those already receiving biologies should be made on a case-by-case basis, considering the patient's needs, the characteristics of the biologic required, and the clinical development programs of the applicable SEB.

Analytical tools for characterizing biopharmaceuticals and the implications for biosimilars

Biologics such as monoclonal antibodies are much more complex than small-molecule drugs, which raises challenging questions for the development and regulatory evaluation of follow-on versions of such biopharmaceutical products (also known as biosimilars) and their clinical use once patent protection for the pioneering biologic has expired. With the recent introduction of regulatory pathways for follow-on versions of complex biologics, the role of analytical technologies in comparing biosimilars with the corresponding reference product is attracting substantial interest in establishing the development requirements for biosimilars. Here, we discuss the current state of the art in analytical technologies to assess three characteristics of protein biopharmaceuticals that regulatory authorities have identified as being important in development strategies for biosimilars: post-translational modifications, three-dimensional structures and protein aggregation.

Fabry disease, enzyme replacement therapy and the significance of antibody responses

Fabry disease is an X-linked disorder caused by a deficiency of α-galactosidase A. This leads to a progressive accumulation of globotriaosylceramide in tissues throughout the body. Cardiac, renal and neurological manifestations are common and life expectancy is significantly reduced relative to the general population. Management of Fabry disease involves the administration of intravenous enzyme replacement therapy (ERT). Two forms - agalsidase alfa and agalsidase beta - have been licensed in certain jurisdictions and are generally well tolerated; however, some patients develop antibodies to the infused enzyme, which may impair the efficacy and safety of treatment. Agalsidase alfa and agalsidase beta are produced in different systems; this leads to certain differences in post-translational modification that may affect immunogenicity. Immunoglobulin (Ig) G antibodies have frequently been reported in patients with Fabry disease receiving ERT; IgG responses are reported in a greater proportion of patients receiving agalsidase beta than in patients receiving agalsidase alfa. IgE antibodies are less common than IgG antibodies, and have not been observed in patients receiving agalsidase alfa. However, these data are difficult to interpret due to methodological differences in the assessment of seropositivity, and in the doses of enzyme used. The clinical impact of the development of IgG antibodies to ERT in patients with Fabry disease remains unclear, due to lack of data and to the marked heterogeneity of patients both in terms of disease manifestations and response to therapy. Further studies that examine the development of antibodies in patients with Fabry disease and the potential impact of such antibodies on the outcome of ERT are necessary.

Tungsten-induced denaturation and aggregation of epoetin alfa during primary packaging as a cause of immunogenicity

Purpose

Following two cases of neutralizing antibodies to epoetin alfa in an investigational clinical study, a small number of individual syringes of two drug product batches were found to contain unusually high levels of aggregation at the end of the clinical trial.

Methods

We undertook an extensive analytical approach to determine the root-cause of the increased aggregation in the affected batches.

Results

Soluble tungsten was found in the syringes, most likely derived from the pins used to manufacture the syringes. Spiking of epoetin alfa with sodium polytungstate or an extract of tungsten pins used to manufacture the syringes induced the formation of aggregates, both dimers that appeared to be covalently linked by disulphide bonds as well as higher-order aggregates. Sodium polytungstate had also a strong denaturing effect on the protein.

Conclusions

We propose tungsten-mediated unfolding and aggregation of epoetin alfa in pre-filled syringes as a potential root cause for increased immunogenicity. This finding may be more broadly applicable to this and other classes of therapeutic proteins.

Biosimilars 2.0: guiding principles for a global "patients first" standard

In the European Union, biosimilar products have been approved since 2006 under an abbreviated pathway that leverages their similarity to an existing "reference" biological product. The products approved to date are based on recombinant versions of endogenous proteins with well-understood structures and pharmacology, but complicated safety and immunogenicity profiles. The period during the 2000s that included the first reviews, approvals, sale and use of biosimilars, is referred to herein as "Biosimilars 1.0." Over the next several years, a new and advanced tranche of biosimilars will be developed for complex reference products, including medicines used in the treatment of cancer and autoimmune diseases. A global market for biosimilars is developing, and this may well foreshadow the beginning of the second era of product development. This Biosimilars 2.0 period will likely be characterized by the development of complex products, global harmonization of standards, and the increasing demand for long-term monitoring of pharmaceuticals. The products developed in this period should exhibit high levels of fidelity to the reference products and should be rigorously evaluated in analytical, non-clinical and clinical comparisons. Additionally, Biosimilars 2.0 manufacturers should strive for transparency in their labels and take proactive strides to be accountable to providers and patients for the quality of their products. An important opportunity now exists for the healthcare community, industry and regulators to work in partnership to outline the appropriate standards for these products to facilitate increased access while meeting patients' needs.

Biosimilar epoetins and other "follow-on" biologics: update on the European experiences

After the patents of biopharmaceuticals have expired, based on specific regulatory approval pathways copied products ("biosimilars" or "follow-on biologics") have been launched in the EU. This article summarizes experiences with hematopoietic medicines, namely the epoetins (two biosimilars traded under five different brand names) and the filgrastims (two biosimilars, six brand names). Physicians and pharmacists should be familiar with the legal and pharmacological specialities of biosimilars: The production process can differ from that of the original, clinical indications can be extrapolated, glycoproteins contain varying isoforms, the formulation may differ from the original, and biopharmaceuticals are potentially immunogenic. Only on proof of quality, efficacy and safety, biosimilars are a viable option because of their lower costs.

Impact of product-related factors on immunogenicity of biotherapeutics

All protein therapeutics have the potential to be immunogenic. Several factors, including patient characteristics, disease state, and the therapy itself, influence the generation of an immune response. Product-related factors such as the molecule design, the expression system, post-translational modifications, impurities, contaminants, formulation and excipients, container, closure, as well as degradation products are all implicated. However, a critical examination of the available data shows that clear unequivocal evidence for the impact of these latter factors on clinical immunogenicity is lacking. No report could be found that clearly deconvolutes the clinical impact of the product attributes on patient susceptibility. Aggregation carries the greatest concern as a risk factor for immunogenicity, but the impact of aggregates is likely to depend on their structure as well as on the functionality (e.g., immunostimulatory or immunomodulatory) of the therapeutic. Preclinical studies are not yet capable of assessing the clinically relevant immunogenicity potential of these product-related factors. Simply addressing these risk factors as part of product development will not eliminate immunogenicity. Minimization of immunogenicity has to begin at the molecule design stage by reducing or eliminating antigenic epitopes and building in favorable physical and chemical properties.

Evaluation of the immuno-stimulatory potential of stopper extractables and leachables by using dendritic cells as readout

Recombinant protein pharmaceuticals may bear some risks and undesirable side effects, such as the appearance of immunogenic reactions. The increased incidence of antibody-mediated pure red cell aplasia (PRCA) outside the United States after administration of a human serum albumin (HSA)-free EPREX (recombinant human erythropoietin alpha) formulation was explained with the generation of rubber stopper related leachables, possibly acting as immunogenic adjuvants. In our study, we have investigated the potential of extractable and leachable preparations of three different pharmaceutical relevant stoppers to generate a "danger signal" in a dendritic cell assay. Furthermore, the investigated extractable and leachable preparations were characterized by NMR and a micelle-based polysorbate quantification method. In summary, we could demonstrate that stopper extractables, either generated by extraction or by leaching conditions, were not acting as danger signals for dendritic cells. Instead we identified degradation products of polysorbate 80, oleic acid and follow-up products, occur only under very accelerated conditions (100 degrees C for 4 days) as a potential stimulator for these immune cells. As this degradation did not occur at real-time, the authors however do not consider their finding to be linked to any direct safety implications of polysorbate-containing formulations in clinical practice.