我国生物医药企业发展建议

近年来,国外生物医药产业发展迅速,在发达国家,生物医药产品在药品市场中已占有了重要地位,哺乳动物细胞表达的产品已经占据生物医药的主流地位。相比之下,我国生物医药品种主要采用简单的大肠杆菌、酵母表达技术,技术难度较高的哺乳动物细胞药品与国外差距显著,因此,哺乳动物表达的生物药品将成为国内生物医药企业的重要发展机会。多年来,鉴于我国从发达国家获得生物技术转让少,国内生物医药发展需立足于自主研发,建立高效的研发技术平台,选择合适的开发项目,促进企业的发展。     

关于我国药典重组DNA技术产品总论的思考

自1982年全球第一个生物技术药物“基因重组人胰岛素”、1989年中国批准第一个生物技术药物“重组人干扰素α1b”上市以来,生物技术药物已成为制药业中发展最快、活力最强和技术含量最高的领域。药品的规范生产与质量控制与其安全有效性密切相关,欧美药典中均设有对此类药品质量控制的总体要求。《中国药典》2010版三部已收录包括12类共计34个品种的重组DNA技术产品各论,在进一步保障药品安全、提高质量控制水平的编制指导思想下,《中国药典》2015版拟纳入对重组DNA技术产品的总体要求,本文就相关起草工作从产品涉及范畴、制造与产品检定等方面进行阐述。     

美国、欧盟和中国生物技术药物的比较

按照相同表达系统表达的相同氨基酸序列的产品视为同种产品,而不同表达系统表达的相同氨基酸序列的产品视为不同产品的原则,归纳总结了美国、欧盟和中国已批准上市的生物技术药物。美国FDA批准的以基因工程产品、抗体工程产品和细胞工程产品为主要代表的生物技术药物共79种(18种为大肠杆菌表达,8种为酵母表达,53种为哺乳动物细胞培养生产),其中基因重组蛋白质药物为64种。欧盟批准了49种基因重组酶、激素或细胞因子,11种基因重组治疗性抗体和5种基因重组疫苗。在欧美60％-70％的产品由哺乳动物细胞表达。中国批准了27种生物技术药物。比较了美国、欧盟和中国生物制药的特点。     

Recombinant protein production and streptomycetes

The biopharmaceutical market has come a long way since 1982, when the first biopharmaceutical product, recombinant human insulin, was launched. Just over 200 biopharma products have already gained approval. The global market for biopharmaceuticals which is currently valued at over US$99 billion has been growing at an impressive compound annual growth rate over the previous years. To produce these biopharmaceuticals and other industrially important heterologous proteins, different prokaryotic and eukaryotic expression systems are used. All expression systems have some advantages as well as some disadvantages that should be considered in selecting which one to use. Choosing the best one requires evaluating the options--from yield to glycosylation, to proper folding, to economics of scale-up. No host cell from which all the proteins can be universally expressed in large quantities has been found so far. Therefore, it is important to provide a variety of host-vector expression systems in order to increase the opportunities to screen for the most suitable expression conditions or host cell. In this overview, we focus on Streptomyces lividans, a Gram-positive bacterium with a proven excellence in secretion capacity, as host for heterologous protein production. We will discuss its advantages and disadvantages, and how with systems biology approaches strains can be developed to better producing cell factories.     

全球生物制药产业发展态势

传统化学制药的黄金时代结束,新化学药品数量下降,而生物技术药物已成为当今最活跃和发展最迅速的领域。随着基因组和蛋白质组研究的深入,越来越多与人类疾病发展相关的靶标被确定,生物制药将有更多的机会获得突破性进展。综述了全球生物制药产业发展的几个态势,主要有：（1）全球生物制药产业的研究成果数量增长迅速;（2）生物制药依然是生物技术产业的重点领域,生物技术药物市场发展规模逐渐扩大,市场集中度高,主要集中于美国和大的跨国公司;（3）生物技术新药在新药研发中的比重越来越大,逐渐成为新药研发主流;（4）生物制药企业间通过加强联盟,来增强新药研发能力和降低新药研发成本;（5）各国政府均重视生物制药产业的发展,出台一系列相关政策。（6）生物疫苗、基因工程药物和基因药物具有良好的市场前景。     

Biosimilars--global issues, national solutions

Biotechnology derived medicinal products are presently the best characterized biologicals with considerable production and clinical experience, and have revolutionized the treatment of some of the most difficult-to-treat diseases, prolonging and improving the quality of life and patient care. They are also currently one of the fastest growing segments of the pharmaceutical industry market. The critical challenge that the biopharmaceutical industry is facing is the expiry of patents for the first generation of biopharmaceuticals, mainly recombinant DNA derived products, such as interferons, growth hormone and erythropoetin. The question that immediately arose was how should such copies of the originator products be licensed, bearing in mind that they are highly complex biological molecules produced by equally complex biological production processes with their inherent problem of biological variability. Copying biologicals is much more complex than copying small molecules and the critical issue was how to handle the licensing of products if relying in part on data from an innovator product. Since 2004 there has been considerable international consultation on how to deal with biosimilars and biological copy products. This has led to a better understanding of the challenges in the regulatory evaluation of the quality, safety and efficacy of "biosimilars", to the exchange of information between regulators, as well as to the identification of key issues. The aim of this article is to provide a brief overview of the scientific and regulatory challenges faced in developing and evaluating similar biotherapeutic products for global use. It is intended as an introduction to the series of articles in this special issue of Biologicals devoted to similar biotherapeutic products.     

Proteomic studies support the use of multi-product immunoassays to monitor host cell protein impurities

In the biopharmaceutical industry, recombinant protein drugs are commonly produced in Chinese hamster ovary (CHO) cells. During the development process, removal of CHO cell-derived proteins from the biopharmaceutical product is monitored using multi-product immunoassays. Such immunoassays are developed by raising antibodies to a single CHO cell protein preparation. However, these assays are utilized to monitor CHO cell protein impurities during the recovery of products from different CHO cell lines. To address whether underlying differences between CHO cell lines result in sufficient protein expression changes to exclude the suitability of multi-product immunoassays, a comparative proteomics study of three independently generated CHO cell lines was performed. Statistical analysis of over 1000 proteins resolved by 2-D PAGE demonstrated that the protein expression profiles of three different CHO cell lines exhibit very few differences in protein expression. Only 11 qualitative changes in protein expression and 26 quantitative changes greater than two-fold were observed. Identification of protein spots by mass spectrometry revealed that many of the observed changes were due to post-translational modifications rather than expression of novel proteins in each cell line. These results suggest that multi-product immunoassays are suitable for monitoring host cell proteins in biopharmaceuticals produced in different CHO cell lines.     

Biosimilars: a regulatory perspective from America

Biosimilars are protein products that are sufficiently similar to a biopharmaceutical already approved by a regulatory agency. Several biotechnology companies and generic drug manufacturers in Asia and Europe are developing biosimilars of tumor necrosis factor inhibitors and rituximab. A biosimilar etanercept is already being marketed in Colombia and China. In the US, several natural source products and recombinant proteins have been approved as generic drugs under Section 505(b)(2) of the Food, Drug, and Cosmetic Act. However, because the complexity of large biopharmaceuticals makes it difficult to demonstrate that a biosimilar is structurally identical to an already approved biopharmaceutical, this Act does not apply to biosimilars of large biopharmaceuticals. Section 7002 of the Patient Protection and Affordable Care Act of 2010, which is referred to as the Biologics Price Competition and Innovation Act of 2009, amends Section 351 of the Public Health Service Act to create an abbreviated pathway that permits a biosimilar to be evaluated by comparing it with only a single reference biological product. This paper reviews the processes for approval of biosimilars in the US and the European Union and highlights recent changes in federal regulations governing the approval of biosimilars in the US.     

Large scale production of recombinant human lactoferrin in the milk of transgenic cows

The limited capacity of current bioreactors has led the biopharmaceutical industry to investigate alternative protein expression systems. The milk of transgenic cattle may provide an attractive vehicle for large-scale production of biopharmaceuticals, but there have been no reports on the characteristics of such recombinant proteins. Here we describe the production of recombinant human lactoferrin (rhLF), an iron-binding glycoprotein involved in innate host defense, at gram per liter concentrations in bovine milk. Natural hLF from human milk and rhLF had identical iron-binding and -release properties. Although natural hLF and rhLF underwent differential N-linked glycosylation, they were equally effective in three different in vivo infection models employing immunocompetent and leukocytopenic mice, and showed similar localization at sites of infection. Taken together, the results illustrate the potential of transgenic cattle in the large-scale production of biopharmaceuticals.     

Recent developments in miRNA based recombinant protein expression in CHO

Biotechnology Letters - It is widely accepted that the growing demand for recombinant therapeutic proteins has led to the expansion of the biopharmaceutical industry and the development of...     

Moss-based production of asialo-erythropoietin devoid of Lewis A and other plant-typical carbohydrate determinants

Protein therapeutics represent one of the most increasing areas in the pharmaceutical industry. Plants gain acceptance as attractive alternatives for high-quality and economical protein production. However, as the majority of biopharmaceuticals are glycoproteins, plant-specific N-glycosylation has to be taken into consideration. In Physcomitrella patens (moss), glyco-engineering is an applicable tool, and the removal of immunogenic core xylose and fucose residues was realized before. Here, we present the identification of the enzymes that are responsible for terminal glycosylation (α1,4 fucosylation and β1,3 galactosylation) on complex-type N-glycans in moss. The terminal trisaccharide consisting of α1,4 fucose and β1,3 galactose linked to N-acetylglucosamine forms the so-called Lewis A epitope. This epitope is rare on moss wild-type proteins, but was shown to be enriched on complex-type N-glycans of moss-produced recombinant human erythropoietin, while unknown from the native human protein. Via gene targeting of moss galactosyltransferase and fucosyltransferase genes, we identified the gene responsible for terminal glycosylation and were able to completely abolish the formation of Lewis A residues on the recombinant biopharmaceutical.     

The production of biopharmaceuticals in plant systems

Biopharmaceuticals present the fastest growing segment in the pharmaceutical industry, with an ever widening scope of applications. Whole plants as well as contained plant cell culture systems are being explored for their potential as cheap, safe, and scalable production hosts. The first plant-derived biopharmaceuticals have now reached the clinic. Many biopharmaceuticals are glycoproteins; as the Golgi N-glycosylation machinery of plants differs from the mammalian machinery, the N-glycoforms introduced on plant-produced proteins need to be taken into consideration. Potent systems have been developed to change the plant N-glycoforms to a desired or even superior form compared to the native mammalian N-glycoforms. This review describes the current status of biopharmaceutical production in plants for industrial applications. The recent advances and tools which have been utilized to generate glycoengineered plants are also summarized and compared with the relevant mammalian systems whenever applicable.     

Transgenic plants as factories for biopharmaceuticals

Plants have considerable potential for the production of biopharmaceutical proteins and peptides because they are easily transformed and provide a cheap source of protein. Several biotechnology companies are now actively developing, field testing, and patenting plant expression systems, while clinical trials are proceeding on the first biopharmaceuticals derived from them. One transgenic plant-derived biopharmaceutical, hirudin, is now being commercially produced in Canada for the first time. Product purification is potentially an expensive process, and various methods are currently being developed to overcome this problem, including oleosin-fusion technology, which allows extraction with oil bodies. In some cases, delivery of a biopharmaceutical product by direct ingestion of the modified plant potentially removes the need for purification. Such biopharmaceuticals and edible vaccines can be stored and distributed as seeds, tubers, or fruits, making immunization programs in developing countries cheaper and potentially easier to administer. Some of the most expensive biopharmaceuticals of restricted availability, such as glucocerebrosidase, could become much cheaper and more plentiful through production in transgenic plants.     

Genetic engineering approaches to improve posttranslational modification of biopharmaceuticals in different production platforms

The number of approved biopharmaceuticals, where product quality attributes remain of major importance, is increasing steadily. Within the available variety of expression hosts, the production of biopharmaceuticals faces diverse limitations with respect to posttranslational modifications (PTM), while different biopharmaceuticals demand different forms and specifications of PTMs for proper functionality. With the growing toolbox of genetic engineering technologies, it is now possible to address general as well as host- or biopharmaceutical-specific product quality obstacles. In this review, we present diverse expression systems derived from mammalians, bacteria, yeast, plants, and insects as well as available genetic engineering tools. We focus on genes for knockout/knockdown and overexpression for meaningful approaches to improve biopharmaceutical PTMs and discuss their applicability as well as future trends in the field.     

The cost-effectiveness of biopharmaceuticals: A look at the evidence

Due to the increasing availability and costs of biopharmaceuticals, policymakers are questioning whether they provide good value relative to other health interventions and many are increasingly relying on cost-utility analyses (CUAs) to supplement decision-making. Analyzing data from the Tufts Medical Center Cost-Effectiveness Analysis Registry, this study critically reviewed the cost-utility literature for biopharmaceuticals and compared their value to other health interventions. Of 2,383 studies in the registry through 2009, biopharmaceutical CUAs comprised the sixth largest category of interventions at 11%. Characteristics of biopharmaceutical articles were similar to other CUAs; however, they displayed slightly better quality. The median cost-effectiveness ratio of biopharmaceuticals was less favorable (i.e., higher) than other interventions, though many seem to provide value for money. A logistic regression showed that among biopharmaceuticals the cost-effectiveness of industry-sponsored studies and products that treat infectious diseases were significantly more likely to be favorable (less than the overall median), while cancer and neurological treatments were significantly less likely.Key words: biopharmaceuticals, cost-effectiveness, cost-utility analysis, value for money, quality adjusted life-year, economic analysis     

生物制药的现状和未来（二）：发展趋势与希望

随着基因组和蛋白质组研究的深入,越来越多的与人类疾病发展相关的靶标被确定,使得我们能够研发更精确的药物来防治这些疾病。这意味着生物制药将有更多机会获得突破性进展,最终将使更多更好的生物技术药物被批准上市。综述了生物制药发展的几个趋势,主要有:(1)哺乳动物细胞表达的产品将在相当长的时间内占统治地位;(2)治疗性抗体将会是生物制药领域第二次创新高潮;(3)越来越多分子量大、结构复杂的功能蛋白将被开发成生物技术药物,尤其是用于治疗遗传性疾病的药物;(4)对已批准上市的生物技术药物的化学修饰尤其是PEG化以改善药物性能;(5)通过某些药物的定点突变获得第二代新生物技术药物,如胰岛素、EPO和t-PA的突变体;(6)组织工程、细胞治疗和基因治疗充满了机遇和挑战。     

A new large‐scale manufacturing platform for complex biopharmaceuticals

Complex biopharmaceuticals, such as recombinant blood coagulation factors, are addressing critical medical needs and represent a growing multibillion‐dollar market. For commercial manufacturing of such, sometimes inherently unstable, molecules it is important to minimize product residence time in non‐ideal milieu in order to obtain acceptable yields and consistently high product quality. Continuous perfusion cell culture allows minimization of residence time in the bioreactor, but also brings unique challenges in product recovery, which requires innovative solutions. In order to maximize yield, process efficiency, facility and equipment utilization, we have developed, scaled‐up and successfully implemented a new integrated manufacturing platform in commercial scale. This platform consists of a (semi‐)continuous cell separation process based on a disposable flow path and integrated with the upstream perfusion operation, followed by membrane chromatography on large‐scale adsorber capsules in rapid cycling mode. Implementation of the platform at commercial scale for a new product candidate led to a yield improvement of 40% compared to the conventional process technology, while product quality has been shown to be more consistently high. Over 1,000,000 L of cell culture harvest have been processed with 100% success rate to date, demonstrating the robustness of the new platform process in GMP manufacturing. While membrane chromatography is well established for polishing in flow‐through mode, this is its first commercial‐scale application for bind/elute chromatography in the biopharmaceutical industry and demonstrates its potential in particular for manufacturing of potent, low‐dose biopharmaceuticals. Biotechnol. Bioeng. 2012; 109: 3049–3058. © 2012 Wiley Periodicals, Inc.     

Fractionation of follicle stimulating hormone charge isoforms in their native form by preparative electrophoresis technology

Complex glycoprotein biopharmaceuticals, such as follicle stimulating hormone (FSH), erythropoietin and tissue plasminogen activator consist of a range of charge isoforms due to the extent of sialic acid capping of the glycoprotein glycans. Sialic acid occupies the terminal position on the oligosaccharide chain, masking the penultimate sugar residue, galactose from recognition and uptake by the hepatocyte asialoglycoprotein receptor. It is therefore well established that the more acidic charge isoforms of glycoprotein biopharmaceuticals have higher in vivo potencies than those of less acidic isoforms due to their longer serum half-life. Current strategies for manipulating glycoprotein charge isoform profile involve cell engineering or altering bioprocesss parameters to optimise expression of more acidic or basic isoforms, rather than downstream separation of isoforms. A method for the purification of a discrete range of bioactive recombinant human FSH (rhFSH) charge isoforms based on Gradiflowtrade mark preparative electrophoresis technology is described. Gradiflowtrade mark electrophoresis is scaleable, and incorporation into glycoprotein biopharmaceutical production bioprocesses as a potential final step facilitates the production of biopharmaceutical preparations of improved in vivo potency.     

Process analytical technology (PAT) tools for the cultivation step in biopharmaceutical production

The process analytical technology (PAT) initiative is now 10 years old. This has resulted in the development of many tools and software packages dedicated to PAT application on pharmaceutical processes. However, most applications are restricted to small molecule drugs, mainly for the relatively simple process steps like drying or tableting where only a limited number of parameters need to be controlled. A big challenge for PAT still lies in applications for biopharmaceuticals and then especially in the cultivation process step, where the quality of a biopharmaceutical product is largely determined. This review gives an overview of the currently available tools for monitoring and controlling the biopharmaceutical cultivation step and of the main challenges for the most common cell platforms (i.e. Escherichia coli, yeast, and mammalian cells) used in biopharmaceutical manufacturing. The real challenge is to understand how intracellular mechanisms (from synthesis to excretion) influence the quality of biopharmaceuticals and how these mechanisms can be monitored and controlled to yield the desired end product quality. Modern “omics” tools and advanced process analyzers have opened up the way for PAT applications for the biopharmaceutical cultivation process step.     

用多孔微载体大规模长期培养动物细胞的方法

长期大规模高密度动物细胞培养是生物制药产业中的关键技术,文中介绍了利用多孔微载体在中试规模生物反应器中长期大规模连续培养分泌尿激酶 原的DNA重组中国仓鼠卵巢细胞（rCHO)的方法。