What's fueling the biotech engine?

Comprehensive insight into exploring the potential of microbial enzymes in cancer therapy: Progress, challenges, and opportunities: A review

Microbial enzymes are crucial catalysts in various industries due to their versatility and efficiency. The microbial enzymes market has recently expanded due to increased demand for many reasons. Among them are eco-friendly solutions, developing novel microbial strains with enhanced enzymes that perform under harsh conditions, providing sustainability, and raising awareness about the benefits of enzyme-based products. By 2030, the global enzyme market is expected to account for $525 billion, with a growth rate of 6.7 %. L-asparaginase and L-glutaminase are among the leading applied microbial enzymes in antitumor therapy, with a growing market share of 16.5 % and 9.5 %, respectively. The use of microbial enzymes has opened new opportunities to fight various tumors, including leukemia, lymphosarcoma, and breast cancer, which has increased their demand in the pharmaceutical and medicine sectors. Despite their promising applications, commercial use of microbial enzymes faces challenges such as short half-life, immunogenicity, toxicity, and other side effects. Therefore, this review explores the industrial production, purification, formulation, and commercial utilization of microbial enzymes, along with an overview of the global enzyme market. With ongoing discoveries of novel enzymes and their applications, enzyme technology offers promising avenues for cancer treatment and other therapeutic interventions.

Mechanistic Insights into the Adsorption of Monoclonal Antibodies at the Water/Vapor Interface

Monoclonal antibodies (mAbs) are active components of therapeutic formulations that interact with the water-vapor interface during manufacturing, storage, and administration. Surface adsorption has been demonstrated to mediate antibody aggregation, which leads to a loss of therapeutic efficacy. Controlling mAb adsorption at interfaces requires a deep understanding of the microscopic processes that lead to adsorption and identification of the protein regions that drive mAb surface activity. Here, we report all-atom molecular dynamics (MD) simulations of the adsorption behavior of a full IgG1-type antibody at the water/vapor interface. We demonstrate that small local changes in the protein structure play a crucial role in promoting adsorption. Also, interfacial adsorption triggers structural changes in the antibody, potentially contributing to the further enhancement of surface activity. Moreover, we identify key amino acid sequences that determine the adsorption of antibodies at the water-air interface and outline strategies to control the surface activity of these important therapeutic proteins.

Protein Design: From the Aspect of Water Solubility and Stability

Water solubility and structural stability are key merits for proteins defined by the primary sequence and 3D-conformation. Their manipulation represents important aspects of the protein design field that relies on the accurate placement of amino acids and molecular interactions, guided by underlying physiochemical principles. Emulated designer proteins with well-defined properties both fuel the knowledge-base for more precise computational design models and are used in various biomedical and nanotechnological applications. The continuous developments in protein science, increasing computing power, new algorithms, and characterization techniques provide sophisticated toolkits for solubility design beyond guess work. In this review, we summarize recent advances in the protein design field with respect to water solubility and structural stability. After introducing fundamental design rules, we discuss the transmembrane protein solubilization and de novo transmembrane protein design. Traditional strategies to enhance protein solubility and structural stability are introduced. The designs of stable protein complexes and high-order assemblies are covered. Computational methodologies behind these endeavors, including structure prediction programs, machine learning algorithms, and specialty software dedicated to the evaluation of protein solubility and aggregation, are discussed. The findings and opportunities for Cryo-EM are presented. This review provides an overview of significant progress and prospects in accurate protein design for solubility and stability.

A Hybrid MCDM Model for Evaluating Strategic Alliance Partners in the Green Biopharmaceutical Industry

Since the rise of strategic alliances which play such an important role in industry today, the biopharmaceutical industry worldwide has entered an era of rapid change and collaborative thinking. The strategic alliance is one of the most important strategies for the green biopharmaceutical industry. Member organizations in these alliances work together to create more advantageous biotechnologies based on environmental protection to achieve mutual benefits. In the past, there have been only a few studies discussing partner evaluations and the selection process for the green biopharmaceutical industry, so the criteria or indicators are still not complete. Therefore, this study proposes a novel multi-criteria decision-making (MCDM) framework for strategic alliance partner evaluation that combines the best-worst method (BWM) and the fuzzy TOPSIS technique based on the concept of aspiration level (called fuzzy TOPSIS-AL) to evaluate the performance and priority rankings of strategic alliance partners. The BWM overcomes the shortcomings of small sample sizes and streamlines the number of conventional pairwise comparisons needed. The fuzzy TOPSIS-AL technique introduces the concept of the aspiration level, thereby leading to more reasonable suggestions for improvement. In addition, data from a multinational green biopharmaceutical company survey are utilized to demonstrate the validity and applicability of the proposed model.

Controlling the Glycosylation Profile in mAbs Using Time-Dependent Media Supplementation

In order to meet desired drug product quality targets, the glycosylation profile of biotherapeutics such as monoclonal antibodies (mAbs) must be maintained consistently during manufacturing. Achieving consistent glycan distribution profiles requires identifying factors that influence glycosylation, and manipulating them appropriately via well-designed control strategies. Now, the cell culture media supplement, MnCl2, is known to alter the glycosylation profile in mAbs generally, but its effect, particularly when introduced at different stages during cell growth, has yet to be investigated and quantified. In this study, we evaluate the effect of time-dependent addition of MnCl2 on the glycan profile quantitatively, using factorial design experiments. Our results show that MnCl2 addition during the lag and exponential phases affects the glycan profile significantly more than stationary phase supplementation does. Also, using a novel computational technique, we identify various combinations of glycan species that are affected by this dynamic media supplementation scheme, and quantify the effects mathematically. Our experiments demonstrate the importance of taking into consideration the time of addition of these trace supplements, not just their concentrations, and our computational analysis provides insight into what supplements to add, when, and how much, in order to induce desired changes.

Continuous countercurrent tangential chromatography for mixed mode post-capture operations in monoclonal antibody purification

Continuous Countercurrent Tangential Chromatography (CCTC) has been shown to demonstrate significant advantages over column chromatography including higher productivity, lower operational pressure, disposable flow path, and lower resin use. Previous applications of CCTC have been limited to initial capture of monoclonal antibodies (mAb) from clarified cell culture harvest. In this present article, a CCTC system was designed and tested for a post-capture antibody purification step. Mixed mode cation exchange-hydrophobic interaction chromatography resins with two different particle sizes were used to reduce host cell protein (HCP), leached protein A, DNA, and aggregates from a mAb stream after a protein A operation. Product output from CCTC was obtained at a steady-state concentration in sharp contrast to the periodic output of product in multi-column systems. The results show up to 101g of mAb/L of resin/hr productivity, which is 10× higher than in a batch column. A 5% yield increase (95% with CCTC vs. 90% in batch column) resulted from optimizing elution pH within a narrow operational window (pH 4-4.5). Contaminant removal was found to be similar to conventional column performance. Data obtained with the smaller particle size resin showed faster binding kinetics leading to reduced CCTC system volume and increased productivity. Buffer and water usage were modeled to show potential for utilization of in-line mixing and buffer tank volume reduction. The experimental results were used to perform a scale up exercise that predicts a compact CCTC flow path for 500 and 2000L batches using commercially available membranes. These results demonstrate the potential of using CCTC for post-capture operations as an alternative to packed bed chromatography, and provide a framework for the design and development of an integrated continuous bioprocessing platform based on CCTC technology.

History of Erythropoiesis-Stimulating Agents, the Development of Biosimilars, and the Future of Anemia Treatment in Nephrology

BACKGROUND

Exogenous replacement of erythropoietin (EPO) by recombinant human EPO has been considered a standard of care for the treatment of anemia in patients with chronic kidney disease for more than 20 years. Genetically engineered biologic proteins derived from human, animal, or microorganism sources are a major area of growth in modern medical care, accounting for one-third of new drug approvals in the past decade. Despite benefit to patients, the use of biologics comes at a significant cost, representing one of the fastest growing segments of strained healthcare budgets around the world.

SUMMARY

Biosimilars, or biologic drugs that are designed to be highly similar to approved reference biologic drugs, have been available in Europe for more than 10 years with no unusual or unexpected effects compared to their reference biologics whose patents have expired. Given the success of the biosimilar approval pathway pioneered in Europe, it has served as a global reference for other regulatory authorities to establish and implement biosimilar licensure frameworks, including the United States (US), the largest pharmaceutical market in the world. Given 10 of the top 25 drugs sold in 2014 were biologics, and considering the rising costs of healthcare, biosimilars have the potential to become a significant part of the US market. Key Messages: For the nephrology community, the recent patent expiries for epoetin alfa (Epogen®, Amgen and Procrit®, Johnson & Johnson) have created the opportunity to develop biosimilar EPOs. And while no biosimilar in this therapeutic class is approved in the US, there are proposed biosimilars in development.

Performance optimization of continuous countercurrent tangential chromatography for antibody capture

Recent studies have demonstrated that continuous countercurrent tangential chromatography (CCTC) can effectively purify monoclonal antibodies from clarified cell culture fluid. CCTC has the potential to overcome many of the limitations of conventional packed bed protein A chromatography. This paper explores the optimization of CCTC in terms of product yield, impurity removal, overall productivity, and buffer usage. Modeling was based on data from bench-scale process development and CCTC experiments for protein A capture of two clarified Chinese Hamster Ovary cell culture feedstocks containing monoclonal antibodies provided by industrial partners. The impact of resin binding capacity and kinetics, as well as staging strategy and buffer recycling, was assessed. It was found that optimal staging in the binding step provides better yield and increases overall system productivity by 8-16%. Utilization of higher number of stages in the wash and elution steps can lead to significant decreases in buffer usage (∼40% reduction) as well as increased removal of impurities (∼2 log greater removal). Further reductions in buffer usage can be obtained by recycling of buffer in the wash and regeneration steps (∼35%). Preliminary results with smaller particle size resins show that the productivity of the CCTC system can be increased by 2.5-fold up to 190 g of mAb/L of resin/hr due to the reduction in mass transfer limitations in the binding step. These results provide a solid framework for designing and optimizing CCTC technology for capture applications. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:430-439, 2016.

The Effects of Light-Accelerated Degradation on the Aggregation of Marketed Therapeutic Monoclonal Antibodies Evaluated by Size-Exclusion Chromatography With Diode Array Detection

Research into the effects that exposure to light can have on therapeutic proteins is essential for ensuring the quality and safety of the medicines in which they are used. It is important to understand the effects of light on aggregation to help avoid undesirable colloidal instabilities, both in the original medicines and in the formats in which they are finally administered. In this study, 5 marketed therapeutic mAbs, namely bevacizumab, cetuximab, infliximab, rituximab, and trastuzumab, were investigated for this purpose. The medicines and 2 diluted preparations in 0.9 NaCl (2 mg/mL and 5 mg/mL)-commonly used in clinical practice-were subjected to controlled light-accelerated degradation. The formation of aggregates was monitored by size-exclusion chromatography. The results indicated that light induced protein aggregation. This process of protein damage was influenced above all by mAb concentration, although the particular characteristics of each mAb were also important. Photodegradation also produced the fragmentation of the mAbs. The damage caused to the mAbs as a result of light-induced aggregation and/or fragmentation was demonstrated both in the medicines and in the diluted preparation forms. These findings should be carefully considered when handling the medicines for administration and when recommending beyond-use dates in normal hospital conditions.

Higher order structure characterization of protein therapeutics by hydrogen/deuterium exchange mass spectrometry

Characterization of therapeutic drugs is a crucial step in drug development in the biopharmaceutical industry. Analysis of protein therapeutics is a challenging task because of the complexities associated with large molecular size and 3D structures. Recent advances in hydrogen/deuterium-exchange mass spectrometry (HDX-MS) have provided a means to assess higher-order structure of protein therapeutics in solution. In this review, the principles and procedures of HDX-MS for protein therapeutics characterization are presented, focusing on specific applications of epitope mapping for protein-protein interactions and higher-order structure comparison studies for conformational dynamics of protein therapeutics.

Complementary MS methods assist conformational characterization of antibodies with altered S-S bonding networks

As therapeutic monoclonal antibodies (mAbs) become a major focus in biotechnology and a source of the next-generation drugs, new analytical methods or combination methods are needed for monitoring changes in higher order structure and effects of post-translational modifications. The complexity of these molecules and their vulnerability to structural change provide a serious challenge. We describe here the use of complementary mass spectrometry methods that not only characterize mutant mAbs but also may provide a general framework for characterizing higher order structure of other protein therapeutics and biosimilars. To frame the challenge, we selected members of the IgG2 subclass that have distinct disulfide isomeric structures as a model to evaluate an overall approach that uses ion mobility, top-down MS sequencing, and protein footprinting in the form of fast photochemical oxidation of proteins (FPOP). These three methods are rapid, sensitive, respond to subtle changes in conformation of Cys → Ser mutants of an IgG2, each representing a single disulfide isoform, and may be used in series to probe higher order structure. The outcome suggests that this approach of using various methods in combination can assist the development and quality control of protein therapeutics.

The roots--a short history of industrial microbiology and biotechnology

Early biotechnology (BT) had its roots in fascinating discoveries, such as yeast as living matter being responsible for the fermentation of beer and wine. Serious controversies arose between vitalists and chemists, resulting in the reversal of theories and paradigms, but prompting continuing research and progress. Pasteur's work led to the establishment of the science of microbiology by developing pure monoculture in sterile medium, and together with the work of Robert Koch to the recognition that a single pathogenic organism is the causative agent for a particular disease. Pasteur also achieved innovations for industrial processes of high economic relevance, including beer, wine and alcohol. Several decades later Buchner, disproved the hypothesis that processes in living cells required a metaphysical 'vis vitalis' in addition to pure chemical laws. Enzymes were shown to be the chemical basis of bioconversions. Studies on the formation of products in microbial fermentations, resulted in the manufacture of citric acid, and chemical components required for explosives particularly in war time, acetone and butanol, and further products through fermentation. The requirements for penicillin during the Second World War lead to the industrial manufacture of penicillin, and to the era of antibiotics with further antibiotics, like streptomycin, becoming available. This was followed by a new class of high value-added products, mainly secondary metabolites, e.g. steroids obtained by biotransformation. By the mid-twentieth century, biotechnology was becoming an accepted specialty with courses being established in the life sciences departments of several universities. Starting in the 1970s and 1980s, BT gained the attention of governmental agencies in Germany, the UK, Japan, the USA, and others as a field of innovative potential and economic growth, leading to expansion of the field. Basic research in Biochemistry and Molecular Biology dramatically widened the field of life sciences and at the same time unified them considerably by the study of genes and their relatedness throughout the evolutionary process. The scope of accessible products and services expanded significantly. Economic input accelerated research and development, by encouraging and financing the development of new methods, tools, machines and the foundation of new companies. The discipline of 'New Biotechnology' became one of the lead sciences. Although biotechnology has historical roots, it continues to influence diverse industrial fields of activity, including food, feed and other commodities, for example polymer manufacture, biofuels and energy production, providing services such as environmental protection, and the development and production of many of the most effective drugs. The understanding of biology down to the molecular level opens the way to create novel products and efficient environmentally acceptable methods for their production.

Analysis of the landscape of biologically-derived pharmaceuticals in Europe: dominant production systems, molecule types on the rise and approval trends

A thorough sort of the human drugs approved by the European Medicines Agency (EMA) between its establishment in 1995 until June 2012 is presented herein with a focus on biologically-derived pharmaceuticals. Over 200 (33%) of the 640 approved therapeutic drugs are derived from natural sources, produced via recombinant DNA technology, or generated through virus propagation. A breakdown based on production method, type of molecule and therapeutic category is presented. Current EMA approvals demonstrate that mammalian cells are the only choice for glycoprotein drugs, with Chinese hamster ovary cells being the dominant hosts for their production. On the other hand, bacterial cells and specifically Escherichia coli are the dominant hosts for protein-based drugs, followed by the yeast Saccharomyces cerevisiae. The latter is the dominant host for recombinant vaccine production, although egg-based production is still the main platform of vaccine provision. Our findings suggest that the majority of biologically-derived drugs are prescribed for cancer and related conditions, as well as the treatment of diabetes. The approval rate for biologically-derived drugs shows a strong upward trend for monoclonal antibodies and fusion proteins since 2009, while hormones, antibodies and growth factors remain the most populous categories. Despite a clear pathway for the approval of biosimilars set by the EMA and their potential to drive sales growth, we have only found approved biosimilars for three molecules. In 2012 there appears to be a slow-down in approvals, which coincides with a reported decline in the growth rate of biologics sales.

Gene expression profiling for mechanistic understanding of cellular aggregation in mammalian cell perfusion cultures

Aggregation of baby hamster kidney (BHK) cells cultivated in perfusion mode for manufacturing recombinant proteins was characterized. The potential impact of cultivation time on cell aggregation for an aggregating culture (cell line A) was studied by comparing expression profiles of 84 genes in the extracellular adhesion molecules (ECM) pathway by qRT-PCR from 9 and 25 day shake flask samples and 80 and 94 day bioreactor samples. Significant up-regulation of THBS2 (4.4- to 6.9-fold) was seen in both the 25 day shake flask and 80 and 94 day bioreactor samples compared to the 9 day shake flask while NCAM1 was down-regulated 5.1- to 8.9-fold in the 80 and 94 day bioreactor samples. Subsequent comparisons were made between cell line A and a non-aggregating culture (cell line B). A 65 day perfusion bioreactor sample from cell line B served as the control for 80 and 94 day samples from four different perfusion bioreactors for cell line A. Of the 84 genes in the ECM pathway, four (COL1A1, COL4A1, THBS2, and VCAN) were consistently up-regulated in cell line A while two (NCAM1 and THBS1) were consistently down-regulated. The magnitudes of differential gene expression were much higher when cell lines were compared (4.1- to 44.6-fold) than when early and late cell line B samples were compared (4.4- to 6.9-fold) indicating greater variability between aggregating and non-aggregating cell lines. Based on the differential gene expression results, two mechanistic models were proposed for aggregation of BHK cells in perfusion cultures.

Analyzing the dynamics of cell growth and protein production in mammalian cell fed-batch systems using logistic equations

The logistic modeling approach was used to describe experimental viable cell density (X) and product concentration (P) data from two industrial fed-batch mammalian cell culture processes with maximum product concentrations in the 3.0-9.4 g/l range. In both cases, experimental data were well described by the logistic equations and the resulting specific growth rate and protein productivity profiles provided useful insights into the process kinetics. Subsequently, sensitivity equations for both the X and P models were analyzed which helped characterize the influence of model parameters on X and P time courses. This was augmented by conventional sensitivity analyses where five values of each model parameter, 25% apart, were used to generate X and P time courses. Finally, results from sensitivity analysis were used to simulate X and P time courses that were reflective of typical early- and late-stage fed-batch cell culture processes. Different combinations of the logistic model parameters were used to arrive at the same final product concentration demonstrating the ability of the logistic approach to describe the multitude of process paths that result in the same final product concentration. Overall, the capability of the logistic equations to well describe X and P data from fed-batch cultures, coupled with their ability to simulate the multitude of paths leading up to the desired cell density and product concentration profiles, make them a useful tool during mammalian cell fed-batch process development.

Computer programs for modeling mammalian cell batch and fed-batch cultures using logistic equations

A MATLAB(®) toolbox was developed for applying the logistic modeling approach to mammalian cell batch and fed-batch cultures. The programs in the toolbox encompass sensitivity analyses and simulations of the logistic equations in addition to cell specific rate estimation. The toolbox was first used to generate time courses of the sensitivity equations for characterizing the relationship between the logistic variable and the model parameters. Subsequently, the toolbox was used to describe CHO cell data from batch and fed-batch mammalian cell cultures. Cell density, product, glucose, lactate, glutamine, and ammonia data were analyzed for the batch culture while fed-batch analysis included cell density and product concentration. In all instances, experimental data were well described by the logistic equations and the resulting specific rate profiles were representative of the underlying cell physiology. The 6-variable batch culture data set was also used to compare the logistic specific rates with those from polynomial fitting and discrete derivative methods. The polynomial specific rates grossly misrepresented cell behavior in the initial and final stages of culture while those based on discrete derivatives had high variability due to computational artifacts. The utility of logistic specific rates to guide process development activities was demonstrated using specific protein productivity versus growth rate trajectories for the 3 cultures examined in this study. Overall, the computer programs developed in this study enable rapid and robust analysis of data from mammalian cell batch and fed-batch cultures which can help process development and metabolic flux estimation.

Interspecies scaling and prediction of human clearance: comparison of small- and macro-molecule drugs

Human clearance prediction for small- and macro-molecule drugs was evaluated and compared using various scaling methods and statistical analysis. Human clearance is generally well predicted using single or multiple species simple allometry for macro- and small-molecule drugs excreted renally. The prediction error is higher for hepatically eliminated small-molecules using single or multiple species simple allometry scaling, and it appears that the prediction error is mainly associated with drugs with low hepatic extraction ratio (Eh). The error in human clearance prediction for hepatically eliminated small-molecules was reduced using scaling methods with a correction of maximum life span (MLP) or brain weight (BRW). Human clearance of both small- and macro-molecule drugs is well predicted using the monkey liver blood flow method. Predictions using liver blood flow from other species did not work as well, especially for the small-molecule drugs.

Exploiting the interactions between poly-histidine fusion tags and immobilized metal ions

Immobilized metal affinity chromatography (IMAC) of proteins containing poly-histidine fusion tags is an efficient research tool for purifying recombinant proteins from crude cellular feedstocks at laboratory scale. Nevertheless, to achieve successful purification of large amounts of the target protein for critical therapeutic applications that demand the precise removal of fusion tags, it is important to also take into consideration issues such as protein quality, efficiency, cost effectiveness, and optimal affinity tag choice and design. Despite the many considerations described in this article, it is expected that enhanced selectivity, the primary consideration in the field of protein separation, will continue to see the use of IMAC in solving new purification challenges. In addition, the platform nature of this technology makes it an ideal choice in purifying proteins with unknown properties. Finally, the unique interaction between immobilized metal ions and poly-histidine fusion tag has enabled new developments in the areas of biosensor, immunoassay, and other analytical technologies.

Recombinant immunotherapeutics: current state and perspectives regarding the feasibility and market

Recombinant immunotherapeutics are important biologics for the treatment and prevention of various diseases. Immunotherapy can be divided into two categories, passive and active. For passive immunotherapy, the successes of antibody and cytokine therapeutics represent a promising future and opportunities for improvements. Efforts, such as cell engineering, antibody engineering, human-like glycosylation in yeast, and Fab fragment development, have led the way to improve antibody efficacy while decreasing its high manufacturing costs. Both new cytokines and currently used cytokines have demonstrated therapeutic effects for different indications. As for active immunotherapy, recently approved HPV vaccines have encouraged the development of preventative vaccines for other infectious diseases. Immunogenic antigens of pathogenic bacteria can now be identified by genomic means (reverse vaccinology). Due to the recent outbreaks of pandemic H1N1 influenza virus, recombinant influenza vaccines using virus-like particles and other antigens have also been engineered in several different recombinant systems. However, limitations are found in existing immunotherapeutics for cancer treatment, and recent development of therapeutic cancer vaccines such as MAGE-A3 and NY-ESO-1 may provide alternative therapeutic strategy.

Into the unknown: expression profiling without genome sequence information in CHO by next generation sequencing

The arrival of next-generation sequencing (NGS) technologies has led to novel opportunities for expression profiling and genome analysis by utilizing vast amounts of short read sequence data. Here, we demonstrate that expression profiling in organisms lacking any genome or transcriptome sequence information is feasible by combining Illumina’s mRNA-seq technology with a novel bioinformatics pipeline that integrates assembled and annotated Chinese hamster ovary (CHO) sequences with information derived from related organisms. We applied this pipeline to the analysis of CHO cells which were chosen as a model system owing to its relevance in the production of therapeutic proteins. Specifically, we analysed CHO cells undergoing butyrate treatment which is known to affect cell cycle regulation and to increase the specific productivity of recombinant proteins. By this means, we identified sequences for >13 000 CHO genes which added sequence information of ∼5000 novel genes to the CHO model. More than 6000 transcript sequences are predicted to be complete, as they covered >95% of the corresponding mouse orthologs. Detailed analysis of selected biological functions such as DNA replication and cell cycle control, demonstrated the potential of NGS expression profiling in organisms without extended genome sequence to improve both data quantity and quality.

What's fueling the biotech engine--2008

Despite the global economic slowdown, biologics managed single-digit growth in 2008, driven mainly by continued high growth in sales of antibodies and insulins. Novel biologics in development look promising, but crowding, pricing and reimbursement are emerging as longer-term concerns.

Design of therapeutic proteins with enhanced stability

Therapeutic proteins such as antibodies constitute the most rapidly growing class of pharmaceuticals for use in diverse clinical settings including cancer, chronic inflammatory diseases, kidney transplantation, cardiovascular medicine, and infectious diseases. Unfortunately, they tend to aggregate when stored under the concentrated conditions required in their usage. Aggregation leads to a decrease in antibody activity and could elicit an immunological response. Using full antibody atomistic molecular dynamics simulations, we identify the antibody regions prone to aggregation by using a technology that we developed called spatial aggregation propensity (SAP). SAP identifies the location and size of these aggregation prone regions, and allows us to perform target mutations of those regions to engineer antibodies for stability. We apply this method to therapeutic antibodies and demonstrate the significantly enhanced stability of our mutants compared with the wild type. The technology described here could be used to incorporate developability in a rational way during the screening of antibodies in the discovery phase for several diseases.

Recent drug approvals from the US FDA and EMEA: what the future holds

The decreased productivity of the pharmaceutical industry in terms of new medical entities approved by the US FDA and the European Medicines Agency (EMEA) on a yearly basis has long been debated. This review will analyze overall new drug applications (NDAs) approved by both the FDA and EMEA in 2007, with the aim of finding trends (also looking at the past) that can be used to predict what the future may be. After a general introduction to the regulatory terminology, NDA approvals in 2007 are divided into categories (new applications of old medicines, metabolites, enantiomers and prodrugs, biological products, natural products and small organic molecule new molecular entities) and discussed. General aspects of the NDA approvals, such as historical trends, the length of the drug-discovery process, geography, differences among therapeutic areas, and the relative role of biotech and pharma industries are also outlined. From this analysis, a perspective is gained on some aspects that will probably influence future drug approvals. The conclusion is that 2007 may represent an inflexion point, in terms of quality if not quantity of new approvals, and that the future may be brighter than previously forecast.

mAbs: a business perspective

The twenty two monoclonal antibodies (mAbs) currently marketed in the U.S. have captured almost half of the top-20 U.S. therapeutic biotechnology sales for 2007. Eight of these products have annual sales each of more than $1 B, were developed in the relatively short average period of six years, qualified for FDA programs designed to accelerate drug approval, and their cost has been reimbursed liberally by payers. With growth of the product class driven primarily by advancements in protein engineering and the low probability of generic threats, mAbs are now the largest class of biological therapies under development. The high cost of these drugs and the lack of generic competition conflict with a financially stressed health system, setting reimbursement by payers as the major limiting factor to growth. Advances in mAb engineering are likely to result in more effective mAb drugs and an expansion of the therapeutic indications covered by the class. The parallel development of biomarkers for identifying the patient subpopulations most likely to respond to treatment may lead to a more cost-effective use of these drugs. To achieve the success of the current top-tier mAbs, companies developing new mAb products must adapt to a significantly more challenging commercial environment.

Immunotherapy in acute leukemia

Recent advances in immunotherapy of cancer may represent a successful example in translational research, in which progress in knowledge and technology in immunology has led to new strategies of immunotherapy, and even past failures in many clinical trials have led to a better understanding of basic cancer immunobiology. This article reviews the latest concepts in antitumor immunology and its application in the treatment of cancer, with particular focus on acute leukemia.

Economic issues with follow-on protein products

The economic effects of the possible introduction of 'follow-on' protein products have been the subject of recent debate. Here, we aim to explore the economic issues surrounding this debate using three measures: total sales, product complexity and patent expiry. Our analysis shows that the sales of therapeutic protein products are concentrated in a relatively small number of branded products, which may be the most attractive targets for follow-on development. For the years 2013-2015, we estimate that products representing US$20 billion in annual sales--approximately half of all sales in 2006--can be expected to lose patent protection.

New challenges to medicare beneficiary access to mAbs

Precision binding of monoclonal antibodies (mAbs) to biological targets, their relative clinical success, and expansion of indications following initial approval, are distinctive clinical features. The relatively high cost of mAbs, together with the absence of a regulatory pathway to generics, stand out as distinctive economic features. Based on both literature review and primary data collection we enumerated mAb original approvals, supplemental indications and off-label uses, assessed payer formulary management of mAbs, and determined new challenges to Medicare beneficiary access to mAbs. We found that the FDA has approved 22 mAbs and 30 supplemental indications pertaining to the originally approved mAbs. In addition, there are 46 off-label use citations in officially recognized pharmaceutical compendia. Across Part B carriers and Part D plans, we found considerable variation in terms of coverage and conditions of reimbursement related to on- and off-label uses of mAbs. Our results point to four major challenges facing mAb developers, health care providers, Medicare beneficiaries, payers and policymakers. These include administrative price controls, coverage variation, projected shift from physician- to self-administered mAbs, and comparative effectiveness. We suggest more systematic use of "coverage with evidence development" as a means of optimally addressing these challenges.

Drug-sensing hydrogels for the inducible release of biopharmaceuticals

Drug-dependent dissociation or association of cellular receptors represents a potent pharmacologic mode of action for regulating cell fate and function. Transferring the knowledge of pharmacologically triggered protein-protein interactions to materials science will enable novel design concepts for stimuli-sensing smart hydrogels. Here, we show the design and validation of an antibiotic-sensing hydrogel for the trigger-inducible release of human vascular endothelial growth factor. Genetically engineered bacterial gyrase subunit B (GyrB) (ref. 4) coupled to polyacrylamide was dimerized by the addition of the aminocoumarin antibiotic coumermycin, resulting in hydrogel formation. Addition of increasing concentrations of clinically validated novobiocin (Albamycin) dissociated the GyrB subunits, thereby resulting in dissociation of the hydrogel and dose- and time-dependent liberation of the entrapped protein pharmaceutical VEGF(121) for triggering proliferation of human umbilical vein endothelial cells. Pharmacologically controlled hydrogels have the potential to fulfil the promises of stimuli-sensing materials as smart devices for spatiotemporally controlled delivery of drugs within the patient.

Considerations for the development of therapeutic monoclonal antibodies

An increasing number of Investigational New Drug (IND) applications for therapeutic monoclonal antibodies (mAbs) have been submitted to US FDA over the past several years. Monoclonal antibodies and related products are under development for a wide range of indications. In addition, the diversity of antibody-related products is increasing including IgG2/IgG4 subclasses and engineered Fc regions to enhance or reduce antibody effector functionality. Recent findings highlight the need to more fully characterize these products and their activity. Advances in product characterization tools, immunogenicity assessments, and other bioanalytical assays can be used to better understand product performance and facilitate development.

Assessment of cell engineering strategies for improved therapeutic protein production in CHO cells

Recombinant glycoprotein therapeutics have proven to be invaluable pharmaceuticals for the treatment of various diseases. Chinese hamster ovary (CHO) cells are widely used in industry for the production of these proteins. Several strategies for engineering CHO cells for improved protein production have been tried with considerable results. The focus has mainly been to increase the specific productivity and to extend the culture longevity by preventing programmed cell death. These CHO cell engineering strategies, particularly those developed in Korea, are reviewed here.

Laying the foundations for a bio-economy

Biological technologies are becoming an important part of the economy. Biotechnology already contributes at least 1% of US GDP, with revenues growing as much as 20% annually. The introduction of composable biological parts will enable an engineering discipline similar to the ones that resulted in modern aviation and information technology. As the sophistication of biological engineering increases, it will provide new goods and services at lower costs and higher efficiencies. Broad access to foundational engineering technologies is seen by some as a threat to physical and economic security. However, regulation of access will serve to suppress the innovation required to produce new vaccines and other countermeasures as well as limiting general economic growth.