Comparative testing and pharmacovigilance of biosimilars

Pure Red-Cell Aplasia “Epidemic”—Mystery Completely Revealed?

Starting in 1998, the number of pure red-cell aplasia (PRCA) cases in patients treated with recombinant human erythropoietin (rHuEPO) increased dramatically. Most cases were observed in patients treated with epoetin alfa produced outside the United States. The peak was observed in 2002; since then, the PRCA incidence has declined.

Many factors are likely to have contributed to this upsurge. The molecular structure of the various epoetins and patient characteristics do not seem to play a major role. The route of administration holds some importance, because most PRCA patients received rHuEPO subcutaneously. The peak of PRCA cases overlapped with the removal of human serum albumin from the Eprex formulation (Janssen-Pharmaceutica NV, Beerse, Belgium), for which polysorbate 80 and glycine were substituted. Polysorbate 80 may have increased the immunogenicity of Eprex by eliciting the formation of epoetin-containing micelles or by interacting with leachates released by the uncoated rubber stoppers of prefilled syringes. Compared with the previous formulation, the polysorbate 80 formulation has lower stability, making it more susceptible to stress conditions such as insufficient attention to the cold chain. This situation could facilitate protein denaturation or aggregate formation.

Uncoated rubber stoppers were replaced with coated stoppers, and the cold chain was reinforced; the Eprex formulation has remained unchanged.

Even though the incidence of PRCA returned to very low levels, discriminating the cause–effect relationship of a single action is difficult, given that all occurred with a similar chronology, and that PRCA develops after a relatively long exposure period. Careful observation of future trends of new PRCA cases is thus mandatory.

Biosimilarity Assessment of 2 Filgrastim Therapeutics in Healthy Volunteers

This study aimed to compare the pharmacokinetic, pharmacodynamic, and safety profiles of a proposed biosimilar and innovator filgrastim therapeutics in healthy volunteers. In a crossover design, 23 subjects received a single subcutaneous injection of 300-µg filgrastim, followed by a 7-day washout period. Assessed pharmacokinetic parameters were the maximum observed filgrastim serum concentration (C_max ), time to reach C_max (t_max ), the area under the concentration-time curve (AUC), and elimination half-life. Pharmacodynamics were assessed by the maximum observed absolute neutrophil count effect (E_max ), t_max,E (time to reach E_max ), and the area under the effect of the absolute neutrophil count -time curve. The test/reference ratio (90% confidence intervals) of C_max of 0.992 (0.860-1.143), AUC_0-inf of 0.995 (0.891-1.111), E_max of 0.952 (0.841, 1.078), and area under the effect of the absolute neutrophil count -time curve from time zero to 96 hours of 0.939 (0.854-1.032), were all well within the predefined equivalence boundaries of 80% and 125%. Obtained values for t_max (∼4 hours), t_max,E (∼15 hours), and elimination half-life (∼3.5 hours) were comparable between 2 treatment groups. The local tolerability and incidence of adverse events were comparable, with no clinically meaningful difference between biosimilar and innovator products. Altogether, the results suggested a high similarity of the proposed biosimilar to the innovator filgrastim in healthy volunteers.

Cross-sectional survey of biosimilar insulin utilization in Asia: The Joint Asia Diabetes Evaluation Program

Aims/Introduction

Biosimilar insulin can reduce treatment costs, although the extent of its use is largely unknown. We examined biosimilar insulin use and its associations with the quality of glycemic control using the Joint Asia Diabetes Evaluation register.

Materials and Methods

We carried out a cross‐sectional analysis in 81,531 patients with type 1 and type 2 diabetes enrolled into the Joint Asia Diabetes Evaluation Program from 2007 to 2014. All insulin related terms are extracted from the Joint Asia Diabetes Evaluation portal, and compared clinical profiles between biosimilar and originator insulin users. Multivariate analysis was performed to assess the association of biosimilar insulin compared with originator insulin with dosage, glycated hemoglobin and hypoglycemia events.

Results

Amongst 81,531 patients, 20.5% (n = 16,738) were insulin‐treated. In four countries with high use of biosimilar insulin, 4.7% (n = 719) of insulin users (n = 10,197) were treated with biosimilar insulin (India n = 507, 70.3%; the Philippines n = 90, 12.5%; China n = 62, 8.6%; Vietnam n = 60, 8.3%). Biosimilar insulin users were younger and had higher body mass index, glycated hemoglobin, insulin dosage and more frequent hypoglycemia than originator insulin users. These associations were non‐significant after adjustment for confounders. Only age, college education, diabetes education, lipid control, physical activity and history of cardiovascular complications were independently associated with these quality measures.

Conclusions

Biosimilar insulin use is not uncommon in Asia. Data exclusion due to incomplete capturing of brand names suggests possibly higher use. The multiple determinants of the quality of glycemic control call for establishment of prospective cohorts and diabetes registers to monitor the safety and efficacy of different brands of biosimilar insulin and their impacts on clinical outcomes.

Urinary Versus Recombinant Gonadotropins for Ovarian Stimulation in Women Undergoing Treatment with Assisted Reproductive Technology

Globally, about 10%-15% couples are affected by infertility, with major role being played by the couple's lifestyle. Several gonadotropin preparations (urinary, purified urinary, recombinant, and biosimilars) are available for use. Purified urinary formulations offer numerous advantages over their predecessor, including lesser injection dose required, ability to be administered subcutaneously, less batch-to-batch variability, better efficacy, ability to individualize protocols as per patient's need, better control of developing follicles, less risk of multiple pregnancies, and hyperstimulation. Published results of Cochrane reviews and meta-analysis show no difference in efficacy or safety between urinary and recombinant gonadotropins. In the absence of any significant difference, cost plays an important role in deciding choice of gonadotropins. In this article, we have reviewed the results of comparative clinical trials, Cochrane analysis, and meta-analysis to derive consensus statements regarding efficacy, safety, and cost implications of urinary versus recombinant gonadotropin preparations.

Desafios ao controle da qualidade de medicamentos no Brasil

Resumo Introdução O desenvolvimento científico e tecnológico, assim como a adoção de políticas públicas voltadas à redução do custo dos medicamentos, tem ampliado o acesso da população a alternativas terapêuticas, as quais incluem medicamentos genéricos, biossimilares, nanomedicamentos e complexos não biológicos. As categorias já comercializadas exigem procedimentos próprios para a garantia de sua qualidade, eficácia terapêutica e segurança. Nesse contexto, o presente estudo procura realizar uma avaliação do cenário atual no Brasil sobre esse tema, apontando para situações que certamente terão de ser enfrentadas em um futuro próximo. Metodologia Foi realizado um levantamento de dados nas bases eletrônicas MEDLINE, PubMed e SCIELO, buscando artigos originais, tanto em português quanto em inglês, indexados retrospectivamente até 1999. Foram utilizados termos de busca relevantes em língua portuguesa e inglesa. Mais de 50 artigos científicos foram encontrados. Resultados e Discussão A maioria dos artigos avaliados aponta problemas tanto na fabricação quanto no controle de medicamentos genéricos e biossimilares, seja no mercado internacional, seja no nacional. No entanto, novas formas medicamentosas estão sendo criadas e necessitam do desenvolvimento de legislação e de metodologias específicas para a garantia da qualidade desses produtos. Uma avaliação do atual sistema brasileiro de registro e controle da qualidade aponta falhas e, especialmente, falta de uma farmacovigilância mais bem estruturada e ativa no país. Conclusão O atual cenário demonstra que os órgãos responsáveis no país necessitam rever a atual sistemática utilizada na fabricação e controle de medicamentos e aprimorá-la, bem como se preparar para o enfrentamento de outras demandas, algumas ainda mais complexas, que já se encontram em desenvolvimento.

The process defines the product: what really matters in biosimilar design and production?

Biologic drugs are highly complex molecules produced by living cells through a multistep manufacturing process. The key characteristics of these molecules, known as critical quality attributes (CQAs), can vary based on post-translational modifications that occur in the cellular environment or during the manufacturing process. The extent of the variation in each of the CQAs must be characterized for the originator molecule and systematically matched as closely as possible by the biosimilar developer to ensure bio-similarity. The close matching of the originator fingerprint is the foundation of the biosimilarity exercise, as the analytical tools designed to measure differences at the molecular level are far more sensitive and specific than tools available to physicians during clinical trials. Biosimilar development, therefore, has a greater focus on preclinical attributes compared with the development of an original biological agent. As changes in CQAs can occur at different stages of the manufacturing process, even small modifications to the process can alter biosimilar attributes beyond the point of similarity and impact clinical effectiveness and safety. The manufacturer's ability to provide consistent production and quality control will greatly influence the acceptance of biosimilars. To this end, preventing drift from the required specifications over time and avoiding the various implications brought by product shortage will enhance biosimilar integration into daily practice. As most prescribers are not familiar with this new drug development paradigm, educational programmes will be needed so that prescribers see biosimilars as fully equivalent, efficacious and safe medicines when compared with originator products.

Biologicals and biosimilars: safety issues in Europe

INTRODUCTION

Medicinal products of a biological origin are approved by the EMA at a centralized level. However, there is no harmonization about their use in Europe. The current regulation referring to the safety of biological medicinal products and biosimilars in Europe has been identified. The safety associated with medicinal products of a biological origin is assured by the pharmacovigilance system, which has evolved, but doesn't yet incorporate all of the specific information from this market segment, namely that related to the identification of drugs, and its use - including the prescription and dispensing, given the possibility of interchangeability and substitution. The terminology, information systems and traceability systems aren't entirely appropriate to ensure the safety requirements for therapy with medicinal products of a biological origin. Areas covered: This article aims to identify the prescription and dispensing profiles of reference biological medicines and biosimilars in the EU, and the determinants that support their safe use. Expert opinion: The European pharmacovigilance system must evolve to ensure the safety along all of the biologicals' therapeutic cycle. It must consider the safety for each of the medicines in addition to their safety pattern related to the eventual switching procedure.

Biosimilars in allergic diseases

PURPOSE OF REVIEW

This article realizes an overview on the world of biological and biosimilar drugs in allergic and immunologic diseases' treatment strategies. We started talking about the history of asthma treatment's progresses, continuing to daily biological therapies, concluding with the economic point of view.

RECENT FINDINGS

Nowadays, the only pharmacological-biological approach approved for allergic diseases is omalizumab. Several other monoclonal antibodies are currently running premarketing studies but the costs of these therapies are difficult to be sustained by healthcare systems.

SUMMARY

Several biological treatments have gone or are going off-patent, opening the drug market to biosimilars. In this way, in future, it will be possible to reduce health costs and increase accessibility to therapies that currently are not affordable to all patients.

Biosimilars - terms of use

The impending expiry of the patent on a number of leading biologic drugs has led to a surge in the development of 'biosimilar' or 'follow-on' products. However, in contrast to generic small-molecule medicines, biosimilars are not identical to their reference products. The differences and complexities surrounding both the molecular structure and the manufacturing process for biologics and biosimilars have resulted in a lack of clarity regarding the terms used in different parts of the world to define various aspects of development and utilization such as regulatory approval, pharmacovigilance, interchangeability and treatment-naivety. This makes quantitative evaluation of biosimilars a great challenge to both the scientific community and regulatory agencies. This manuscript attempts to clarify the terms used and address an important knowledge gap which is currently resulting in an increasing rush to position biosimilars for certain indications and patients in the absence of agreed upon definitions.

Key considerations in the preclinical development of biosimilars

Biosimilar development requires several steps: selection of an appropriate reference biologic, understanding the key molecular attributes of that reference biologic and development of a manufacturing process to match these attributes of the reference biologic product. The European Medicines Agency (EMA) and the FDA guidance documents state that, in lieu of conducting extensive preclinical and clinical studies typically required for approval of novel biologics, biosimilars must undergo a rigorous similarity evaluation. The aim of this article is to increase understanding of the preclinical development and evaluation process for biosimilars, as required by the regulatory agencies, that precedes the clinical testing of biosimilars in humans.

Formulary Selection Criteria for Biosimilars: Considerations for US Health-System Pharmacists

Pharmacists will play a key role in evaluating biosimilars for formulary inclusion in the United States. As defined by US law, a biosimilar is a biologic that is highly similar to its reference product, notwithstanding minor differences in clinically inactive components, and should not have clinically meaningful differences from its reference product in safety, purity, and potency. We review biosimilars and the current European Union and US regulatory pathways for biosimilars. Furthermore, we propose a checklist of considerations to ensure that US pharmacists thoroughly evaluate future biosimilars for formulary inclusion. Included in the checklist are considerations related to the availability of preapproval and postapproval safety and efficacy data; differences in product characteristics and immunogenicity between the biosimilar and reference product; manufacturer-related parameters that can affect a reliable supply of quality products; health-system and patient perspectives on product packaging, labeling, storage, and administration; costs and insurance coverage; patient education; interchangeability and differences in the range of indications; and evaluation of institutions' information technology systems.

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.

Bioanalytical challenges of biosimilars

Biologics such as monoclonal antibodies and recombinant proteins represent a significant portion of the pharmaceutical market. With many of the first generation biologics’ patents expiring, an increasing number of biosimilars will be submitted for approval in the near future. The successful development of a biosimilar requires the demonstration of biosimilarity in terms of efficacy, safety and purity to an innovator-approved product. While regulatory frameworks have been established for the approval of biosimilars in several countries, there is not an established guidance for bioanalytical testing of biosimilars. Although there are regulatory guidances and White Papers on testing requirements for biologics in general, there is a need to address the bioanalytical challenges and solutions that apply specifically to the analysis of biosimilars in biological samples. This paper will focus on components of the PK and immunogenicity assays that are critical to biosimilar drug development.

Biosimilars: company strategies to capture value from the biologics market

Patents for several biologic blockbusters will expire in the next few years. The arrival of biosimilars, the biologic equivalent of chemical generics, will have an impact on the current biopharmaceuticals market. Five core capabilities have been identified as paramount for those companies aiming to enter the biosimilars market: research and development, manufacturing, supporting activities, marketing, and lobbying. Understanding the importance of each of these capabilities will be key to maximising the value generated from the biologics patent cliff.

From "blockbusters" to "biosimilars": an opportunity for patients, medical specialists and health care providers

Advances in basic research and research and development plans of pharmaceutical companies are radically changing the kind of available drugs and therapeutic targets. We are switching from predominantly chemical molecules, aimed at treating large populations of patients (blockbuster drugs), to a new generation of products, mostly biotech, aimed at modifying a specific pathogenetic mechanism. In other word we are moving fast to targeted therapy, which represents the first step toward personalized therapy, where the right drug at the right dose is administered to the right person, at the right time. Like the patent expiration of chemical products has corresponded to the development of generic drugs, the expiration of new biotech products will witness the appearance of biosimilars. The latter are biologic products that are highly similar but not identical to the reference medical products in terms of quality, safety and efficacy. This implies specific research, clinical monitoring, physicians updating of knowledge for a safe and appropriate use of these products. We are the beginning of a devolution in patient's care and physicians' practice.

Challenges of developing and validating immunogenicity assays to support comparability studies for biosimilar drug development

Imminent patent expiry for a number of biological products currently on the market (many of which are blockbusters) has created an increasing opportunity for the development of biosimilars in the biotechnology industry. The key for successful biosimilar development is to demonstrate biosimilarity to the originator drug. In addition to demonstrating the similarity of physical and chemical properties between biosimilar and originator compounds, regulatory agencies require that immunogenicity be evaluated in comparative studies between biosimilar and originator drugs. Immunogenicity assays are generally non-quantitative (qualitative) and proving similarity/comparability based on qualitative assays can be very challenging. This review will discuss the challenges of developing and validating immunogenicity assays to support preclinical and clinical comparative studies for biosimilar drug development as well as the challenges in association with the interpretation of the data.

Biosimilars: current perspectives and future implications

Biosimilars are biological products that are the replicas of their innovator biopharmaceuticals. These are developed after patent expiration of innovator biopharmaceuticals and are submitted for separate marketing approval. In view of the structural and manufacturing complexities of biopharmaceuticals, biosimilars should not be considered as “biological generics”. These are rather unique molecules with limited data at time of approval, so there are concerns about the safety and efficacy of biosimilars. This article will address the differences between biosimilars and chemical generics, issues of concern with the use of biosimilars and need of appropriate regulations for their approval.

Tolerability, pharmacokinetics and pharmacodynamics of CMAB007, a humanized anti-immunoglobulin E monoclonal antibody, in healthy Chinese subjects

The goal of the studies presented here was to determine the tolerability, pharmacokinetic and pharmacodynamic profiles of CMAB007, a biosimilar of omalizumab (Xolair; a humanized anti-immunoglobulin E monoclonal antibody), in healthy, male Chinese subjects. Thirty-six healthy Chinese men participated in two open-label, dose-escalation studies: 27 in a single-dose study (150, 300 or 600 mg) and 9 in a multiple-dose study (150 or 300 mg every 4 weeks for 20 weeks). The safety profiles of both studies were generally unremarkable. No drug-related adverse event was observed. CMAB007 exhibited a linear PK profile over the dose range of 150-600 mg. In the single-dose study, maximum concentration (Cmax) was reached within 6-8 d, and Cmax and area under concentration-time curve (AUC) increased linearly with the dose. In the multiple-dose study, steady-state appeared to have been achieved after the third dose. Css-max and AUCτ also showed dose-linearity. A dose-dependent suppression of free IgE was observed during treatment, as a median percentage change from baseline, 91.9-98.8%, in the three single-dose groups. No anti-CMAB007 antibodies were detected after dosing in any subject. Subcutaneous administration of CMAB007 was well-tolerated and seemed to be effective in reducing free IgE in healthy Chinese volunteers, which provides important information for further clinical studies.

Erythropoiesis-stimulating agents in renal medicine

The four currently available erythropoiesis-stimulating agents (ESAs), the main drugs for correcting anemia in patients with chronic kidney disease (CKD), are epoetin alfa, epoetin beta, darbepoetin alfa, and continuous erythropoietin receptor activator. The last two have much longer half-lives, which means they can be administered less frequently. The expiry of the patents for epoetin alfa and epoetin beta some years ago opened up the way for the production of a number of biosimilars that are now marketed in the European Union. Because biosimilars cannot be identical to their originator, a complex and still-evolving regulatory policy has been generated, but there are still a number of issues concerning international naming, automatic substitution, and safety. All ESAs are effective in correcting renal anemia and increasing hemoglobin levels, but the choice of which to use should also take into account their pharmacokinetics and pharmacodynamics, their administration route, and economic issues. Following the publication of a number of trials indicating no benefit (and even possible harm) when ESAs are used to aim at near-normal hemoglobin levels in CKD patients, the hemoglobin target has become a major subject of discussion. According to the position statement of the Anemia Group of the European Renal Best Practice, it should generally be about 11-12 g/dL; however, a risk-benefit evaluation is warranted in individual patients, and high ESA doses driven by hyporesponsiveness should be avoided.

Emerging patient safety issues under health care reform: follow-on biologics and immunogenicity

US health care reform includes an abbreviated pathway for follow-on biologics, also known as biosimilars, in an effort to speed up access to these complex therapeutics. However, a key patient safety challenge emerges from such an abbreviated pathway: immunogenicity reactions. Yet immunogenicity is notoriously difficult to predict, and even cooperative approaches in licensing between companies have resulted in patient safety concerns, injury, and death. Because approval pathways for follow-on forms do not involve cooperative disclosure of methods and manufacturing processes by innovator companies and follow-on manufacturers, the potential for expanded immunogenicity must be taken into account from a risk management and patient safety perspective. The US Institute of Safe Medication Practices (ISMP) has principles of medication safety that have been applied in the past to high-risk drugs. We propose adapting ISMP principles to follow-on biologic forms and creating systems approaches to warn, rapidly identify, and alert providers regarding this emerging patient safety risk. This type of system can be built upon and provide lessons learned as these new drug forms are developed and marketed more broadly.

Biosimilar agents in oncology/haematology: from approval to practice

The regulation of biosimilars is a process that is still developing. In Europe, guidance regarding the approval and use of biosimilars has evolved with the products under consideration. It is now more than 3 years since the first biosimilar agents in oncology support, erythropoiesis-stimulating agents, were approved in the EU. More recently, biosimilar granulocyte colony-stimulating factors have received marketing approval in Europe. This review considers general issues surrounding the introduction of biosimilars and highlights current specific issues pertinent to their use in clinical practice in oncology. Information on marketing approval, extrapolation, labelling, substitution, immunogenicity and traceability of each biosimilar product is important, especially in oncology where patients are treated in repeated therapy courses, often with complicated protocols, and where biosimilars are not used as a unique therapy for replacement of e.g. growth hormone or insulin. While future developments in the regulation of biosimilars will need to address multiple issues, in the interim physicians should remain aware of the inherent differences between biosimilar and innovator products.

New and Generic Anticoagulants and Biosimilars: Safety Considerations

The recent health care changes and approval of a generic low-molecular-weight heparin (LMWH) by the US Food and Drug Administration (FDA) merit a review of the facts regarding the new and generic anticoagulants. Fatal hypotension from anaphylactoid type reactions following heparin administration was responsible for more than 149 deaths all over the world. Researchers detected a heparin-like semisynthetic contaminant, over-sulfated chondroitin sulfate (OSCS), that appeared to be intentional. Low-molecular-weight heparins are produced using unfractionated heparin and OSCS has been found in various batches of LMWHs. Some newer anticoagulants are claiming to be free from the need to monitor for therapeutic effect and bleeding risk. Therefore, monitoring assays are not being developed and there is no antidote to reverse bleeding. In addition, there are concerns about reproducibility, product variation, and quality. In conclusion, although the generic LMWHs and newer anticoagulants may appear to be effective for qualified indications, their safety remains to be a concern.

The new world of biosimilars: what diabetologists need to know about biosimilar insulins

Biosimilar pharmaceuticals are emerging as patent protection on the original biopharmaceutical products expires. However, biopharmaceuticals are particularly complex molecules, and biosimilar insulins present special challenges. In part this reflects their structure and chemical modification after synthesis to attain a biologically active form. Their therapeutic window is narrow and the accuracy of their dosing is highly dependent on the formulation and quality of the administration device. For these reasons, the European Medicines Agency has issued stringent guidelines that must be fulfilled in order to receive approval as a biosimilar soluble insulin. Prescribers should therefore consider issues of manufacture, protein quality, formulation, reliability of supply, and other factors that might affect efficacy, safety and tolerability when making choices regarding the selection of biosimilar products.

Are biosimilars really generics?

IMPORTANCE OF THE FIELD

Ever since the formation of the first biotechnology company almost three decades ago, more than 150 biopharmaceutical products have been marketed across the globe. The oldest of these biotechnology-derived products are now at the end of their patent lives, as a result of which, the development of 'biosimilars' is increasing.

AREAS COVERED IN THE REVIEW

The review highlights aspects in which biosimilars differ from generic drugs.

WHAT THE READER WILL GAIN

The active substance of a biosimilar medicine is similar to the one of the biological reference medicine; however, biosimilars differ from generics of pharmacological drugs in aspects like size and complexity of the active substance, and the nature of the manufacturing process. The manufacture of a biopharmaceutical product is complex and involves several isolation and purification steps. These procedures are proprietary to the manufacturer of the originator product and hence even minor changes in production can have serious implications in terms of safety and efficacy of the product.

TAKE HOME MESSAGE

Biosimilars should not be brought to market using the same procedure applied to generics, and existing and future regulation should prevent inappropriate and automatic substitution of a biosimilar for a reference biopharmaceutical product.

Bioequivalence between novel ready-to-use liquid formulations of the recombinant human GH Omnitrope and the original lyophilized formulations for reconstitution of Omnitrope and Genotropin

OBJECTIVE

Two strengths of a novel ready-to-use liquid preparation of the recombinant human GH (rhGH) Omnitrope were developed to increase the convenience for the patients.

DESIGN

Omnitrope 3.3 mg/ml solution or Omnitrope 6.7 mg/ml solution was compared to Omnitrope 5 mg/ml powder and Genotropin 5 mg/ml powder in terms of pharmacokinetics, pharmacodynamics, safety, and local tolerance after a single s.c. dose of 5 mg.

METHODS

Two randomized, double-blind, single-dose, three-way crossover studies were carried out in 36 young healthy volunteers each. Endogenous GH secretion was suppressed with a 25-h continuous i.v. infusion of octreotide (40 microg/h) starting 1 h before rhGH administration.

RESULTS

Pharmacokinetic parameters were similar for the three treatments in both studies respectively. Bioequivalence criteria were met for area under the concentration-time curve (AUC) and C(max). Likewise, the pharmacodynamic parameters for IGF1, IGF-binding protein 3, and non-esterified fatty acid were similar for all preparations. No differences in adverse events were observed between groups.

CONCLUSIONS

Omnitrope 3.3 mg/ml solution, 6.7 mg/ml solution, and 5 mg/ml powder, and Genotropin 5 mg/ml powder are bioequivalent, have similar pharmacokinetic and pharmacodynamic profiles, and are equally safe. Overall, the products can be considered to be therapeutically interchangeable.

Lessons learned from biosimilar epoetins and insulins

Patients with diabetes and renal failure may already be receiving biosimilar epoetin and may receive biosimilar insulin in the near future. Because these biosimilar pharmaceuticals (or follow-on biologics) are complex protein molecules manufactured in lengthy and inherently variable processes involving living organisms, they have the potential to induce an immunogenic, rather than a therapeutic, response. This response is dependent as much on the method of manufacture and formulation, as on the protein itself. Apparently small and innocuous differences in manufacture and formulation can lead to unforeseen clinical consequences. This article discusses two case studies illustrating this principle, that of three insulin formulations which were physicochemically similar to comparator insulins, but with pharmacokinetic and pharmacodynamic profiles sufficiently different to have potentially serious clinical consequences and that of Eprex, for which an apparently minor change in one formulation caused an upsurge of cases of pure red cell aplasia which resulted in fatalities or complete transfusion dependence. Comprehensive and rigorous testing and long-term pharmacovigilance programmes are essential to detect and forestall such consequences.

Mammalian target of rapamycin (mTOR) induces proliferation and de-differentiation responses to three coordinate pathophysiologic stimuli (mechanical strain, hypoxia, and extracellular matrix remodeling) in rat bladder smooth muscle

Maladaptive bladder muscle overgrowth and de-differentiation in human bladder obstructive conditions is instigated by coordinate responses to three stimuli: mechanical strain, tissue hypoxia, and extracellular matrix remodeling.( 1,2) Pathway analysis of genes induced by obstructive models of injury in bladder smooth muscle cells (BSMCs) identified a mammalian target of rapamycin (mTOR)-specific inhibitor as a potential pharmacological inhibitor. Strain-induced mTOR-specific S6K activation segregated differently from ERK1/2 activation in intact bladder ex vivo. Though rapamycin's antiproliferative effects in vascular smooth muscle cells are well known, its effects on BSMCs were previously unknown. Rapamycin significantly inhibited proliferation of BSMCs in response to mechanical strain, hypoxia, and denatured collagen. Rapamycin inhibited S6K at mTOR-sensitive phosphorylation sites in response to strain and hypoxia. Rapamycin also supported smooth muscle actin expression in response to strain or hypoxia-induced de-differentiation. Importantly, strain plus hypoxia synergistically augmented mTOR-dependent S6K activation, Mmp7 expression and proliferation. Forced expression of wild-type and constitutively active S6K resulted in loss of smooth muscle actin expression. Decreased smooth muscle actin, increased Mmp7 levels and mTOR pathway activation during in vivo partial bladder obstruction paralleled our in vitro studies. These results point to a coordinate role for mTOR in BSMCs responses to the three stimuli and a potential new therapeutic target for myopathic bladder disease.

Follow-on protein products: scientific issues, developments and challenges

Scientific and regulatory issues around approval of follow-on protein products, referred to as biosimilars in Europe, have been a topic of great interest and debate recently. The central issue is our limited understanding of how the different quality attributes of a product have an impact on its safety and efficacy. Crucial gaps in our knowledge include a lack of standardization in the way in which data are collected, analyzed and reported, and limitations in the ability of non-clinical tools for predicting clinical safety and efficacy. Complexity of protein products with respect to the numerous quality attributes and complexity of the biotechnology processes and the raw materials add to the challenges. In this paper, recommendations are presented to help at least partially alleviate these challenges.

Optimizing the management of renal anemia: challenges and new opportunities

Erythropoiesis stimulating agents (ESAs) are the main tool to achieve anemia correction in CKD patients. At present six different ESAs are available: epoetin alpha, epoetin beta, epoetin omega, epoetin delta, darbepoetin alpha, and very recently CERA. From one side the patent of older ESAs have expired, and biosimilars (for the moment only of epoetin alpha) have been approved for use in Europe by the European Medicines Agency. However, a number of issues about bioequivalence and how to test it are still to be solved completely. In the mean time pharmaceutical research has kept on working, developing new ESAs and alternative strategies for stimulating erythropoiesis. In this review we present and discuss these points.

Biosimilar therapeutics-what do we need to consider?

Patents for the first generation of approved biopharmaceuticals have either expired or are about to expire. Thus the market is opening for generic versions, referred to as 'biosimilars' (European Union) or 'follow-on protein products' (United States). Healthcare professionals need to understand the critical issues surrounding the use of biosimilars to make informed treatment decisions.The complex high-molecular-weight three-dimensional structures of biopharmaceuticals, their heterogeneity and dependence on production in living cells makes them different from classical chemical drugs. Current analytical methods cannot characterize these complex molecules sufficiently to confirm structural equivalence with reference molecules. Verification of the similarity of biosimilars to innovator biopharmaceuticals remains a key challenge. Furthermore, a critical safety issue, the immunogenicity of biopharmaceuticals, has been highlighted in recent years, confirming a need for comprehensive immunogenicity testing prior to approval and extended post-marketing surveillance.Biosimilars present a new set of challenges for regulatory authorities when compared with conventional generics. While the demonstration of a pharmacokinetic similarity is sufficient for conventional, small-molecule generic agents, a number of issues will make the approval of biosimilars more complicated. Documents recently published by the European Medicines Agency (EMEA) outlining requirements for the market approval of biosimilars provide much-needed guidance. The EMEA has approved a number of biosimilar products in a scientifically rigorous and balanced process. Outstanding issues include the interchangeability of biosimilars and innovator products, the possible need for unique naming to differentiate the various biopharmaceutical products, and more comprehensive labelling for biosimilars to include relevant clinical data.

Biosimilars: opinion of an expert panel in the Middle East

BACKGROUND

Several biotechnology-derived drugs are reaching the end of their patent lives. As a result, so-called biosimilar products are in development, and a few have already gained approval in Europe and other countries such as the USA. Biosimilars, unlike generic versions of conventional drugs, are not identical to their reference product, and their production is complex and sensitive to even slight changes in the manufacturing and storage process. Therefore, the registration of these products requires more stringent evaluation than that for conventional generics.

METHODS AND SCOPE

A consensus group of experts from the Near and Middle East discussed the currently available guidelines for registration of biosimilars--including those produced by the European Medicines Agency (EMEA)--and their application in this region. To inform this report, a literature search was also conducted on PubMed in January 2008, using the search terms 'biosimilar' and 'follow-on biologic'. This paper provides an overview of the issues in the development and registration of biosimilars, a description of the EMEA guidelines and the recommendations of the consensus group for the registration of biosimilars in the Middle East.

FINDINGS

Because of the complex nature of biosimilars and their potential immunogenicity, these products cannot undergo the abbreviated approval process used for generic agents. Instead demonstration of their quality, safety and efficacy, in comparison with their reference biological product, is required.

CONCLUSIONS

The consensus group recommended the implementation of the EMEA guidelines as the basis of Regional guidelines for the registration of biosimilars in the Near and Middle East. Registration would, therefore, require demonstration of the robustness of the manufacturing process and quality-control methods, the comparability of pharmacokinetics, pharmacodynamics, efficacy and safety between the biosimilar and reference product and plans for post-marketing surveillance of the long-term risks and immunogenicity of new biosimilars.

Pharmacy and pharmacology of biosimilars

Biosimilar medicines are biological medicinal products that can obtain a marketing authorization in the EU after the original product (biological reference medicine) has run out of patent. As a prerequisite, studies including clinical trials are to be conducted to compare the quality, safety, and efficacy of the biosimilar and reference medicine. Due to the specific characteristics of biopharmaceuticals like complex 3-dimensional (glyco) protein structure, immunogenicity, production in living organisms, which causes heterogeneity, complex manufacturing process and analysis, interchangeability of the biosimilar with its reference drug product is not guaranteed. In addition, INN (international non-proprietary name) naming and interchangeability, pharmacovigilance, and traceability are subjects for discussion. The aim of this article is to describe the pharmaceutical and pharmacological specialties of biosimilars and to inform about points to consider (like manufacturer, good handling practice, pharmacovigilance, costs), when the use of biosimilars comes into question.

Basic Facts about Biosimilars

Biotechnological drugs have become an essential part of modern pharmacotherapy and are expected to reach a 50% share in the pharmaceutical market in the next few years. The expiry of patent protection for many original biotechnological medicines has led to the development of what are called biosimilars or follow-on biologics. Biosimilars attempt to copy the original technology leading to the production of innovative biotechnological medicines to obtain a product which is similar to the original one. The first two biosimilars have recently been approved in the European Union and one application was rejected. Many more biosimilars will likely see approval in the near future. Our experience with biosimilars has been very limited to date and long-term safety data including immunogenicity are not available. Although biosimilars will likely lower the cost of modern therapies there are issues which have to be discussed at this stage among physicians regarding in particular the differences between biosimilars and generics of the classical chemical drugs, need for appropriate regulations as well as identification of potential problems with biosimilars. Other specific problems which will also be addressed in this review are safety of biosimilars, pharmacovigilance, automatic substitution, naming and labeling/prescription rules.