Since the mid-1970’s, when Kohler and Milstein first discovered the process by which myeloma cells and splenocytes could be fused to produce monoclonal antibodies (MAbs), a whole new world of important therapeutic, prophylactic and diagnostic products has opened up, bringing in huge benefits for patients and manufacturers. The total sales of therapeutic MAbs reached more than $13 billion in 2005. Sixteen of the 18 FDA-approved MAbs came to the market after 1997, and over 150 are currently in clinical development, suggesting their increasing medical importance and the remarkable, recent advancements in development technology…
Tag: <span>monoclonal antibody</span>
The outstanding success and safety record of first generation monoclonal products has created an immense increase in the number of product candidates that need to be evaluated clinically. The concept of platform purification has emerged in response to this need. A platform is a semigeneric, multistep purification procedure that can be applied to a wide range of monoclonal antibodies without extensive method-scouting and optimization. This approach can substantially accelerate process development and hasten inception of clinical trials…
Total market share of biopharmaceuticals is estimated to increase from $33 billion now to more than $45 billion in 2007. These numbers are accounted for by the 64 products approved by European and US regulators and some of the 500 products currently under clinical evaluation. More than 2,000 products are in discovery and preclinical development. Monoclonal antibodies (MAbs) and recombinant glycoproteins constitute a major part of these new biotech leads. The estimated demands for MAbs alone are more than 6,000 kg per year in 2006. Currently, 16 MAbs are licensed by the U.S. Food and Drug Administration (FDA) for pharmaceutical use and more than 130 are in clinical trials. This fast-growing class of biotherapeutics is expected to reach worldwide sales of more than $15 billion per year in 2008. In the coming years, mammalian cell culture technology will remain the production system of choice for MAbs and other recombinant glycoproteins. Therefore, efficient, cost-effective production systems need to be in place to meet the demands…
A growing number of separations’ scientists and process developers are looking beyond protein A sorbents for capture and initial purification of monoclonal antibodies. A variety of strategic and operational goals have prompted examination of alternative immunoglobulin-selective sorbents. Most broadly, many workers wish to eliminate design considerations associated with leached protein A. Also cited is a preference for sorbents that can withstand stringent cleanup using 1 M sodium hydroxide. In some applications, it is desirable to avoid the low-pH elution conditions typically employed with protein A sorbents — conditions that can foster aggregate formation. In still other cases, the target antibody may bind poorly to protein A. Finally, there may be interest in evaluation of immunoglobulin-selective sorbents less costly than protein A sorbents…
Cation exchange chromatography (CEX) is a versatile method for separation of proteins based on exploiting differences in positive electrostatic charges. In CEX, proteins are bound to the negatively charged stationary phase (cation exchangers) and then eluted using a salt gradient. Typically, the liquid-phase pH in CEX is lower than the isoelectric points (pI) of the proteins. CEX has been used to monitor various post-translational modifications such as glycosylation, deamidation, phosphorylation, truncation, oxidation, C-terminal and N-terminal clipping, and N-terminal cyclization. Some of these variants may exhibit different bioactivity. Therefore, it is important to characterize protein variants and monitor the stability of these variants throughout the process of drug discovery, development, and manufacture. Characterization of complex proteins such as antibodies, has traditionally been performed using slab gel-based techniques such as isoelectric focusing (IEF). This technique is qualitative and time consuming. It also generates large quantities of chemical waste from the staining process…
Monoclonal antibodies (MAbs) destined for use in drug-specific assays must meet specific binding criteria, and therefore require much more in the way of development than many protein-specific antibodies. This article describes one way to facilitate the development of well-characterized, high specificity MAbs. Essentially the same techniques have also been used for producing MAbs that are cancer markers and MAbs that are specific for infectious agents. Monoclonal antibody development, as in other endeavors, requires clearly defined goals and an examination of proposed methods to attain them. This has been succinctly stated by the phrase “Start with the end in mind.” Unfortunately, the vast majority of hybridoma development could be more appropriately described by Yogi Berra, “If you don’t know where you are going, you will wind up somewhere else.” In most laboratories, fusions are carried out with the goal of reducing the amount of cell culture and handling required and using the minimum amount of screening. Little or no consideration is given to ensuring that single clones are subjected to the screening tests. Under these conditions, it is little wonder that dozens of fusions can be carried out, each with the same result — no specific antibody found…
lation components that stabilize the molecule in order to provide the desired product storage stability. Generally, an aqueous formulation is preferred; however, the instability of proteins, both physical (e.g. aggregation) and chemical (e.g. deamidation and oxidation), often necessitates the development of lyophilized formulations. In these formulations, selection of the appropriate stabilizing cryoprotectants, lyoprotectants, and bulking agents is critical. Accelerated stability studies are typically used to evaluate the effect of a single factor at a time in order to identify the optimum pH, buffer, and stabilizing excipients. This approach is limited in that many independent time-consuming experiments must be run, the results are obtained only at the evaluated set points, and additional experiments are required to assess potential interactions between the evaluated factors…
Foreign substances, such as disease-causing viruses and other infectious agents are recognized by the body’s immune system as invaders. Parts of the spectrum of our defenses are antibodies that bind these antigens and direct their destruction by other elements of the immune system. Antibodies have two very useful characteristics. First, they are extremely specific; that is, each antibody binds to one particular antigen. Second, the body retains the memory of encounters with antigens, enabling it to reproduce an antibody response to a later attack by that that same agent or disease. These properties make it possible to develop vaccines. It is the first trait of antibodies, their specificity, which makes monoclonal antibody (MAb) technology so valuable. Not only can antibodies be used therapeutically, to protect against disease, they also can help diagnose a wide variety of illnesses and can detect the presence of infectious agents (including biological threat agent). The use of MAbs specific for biological warfare agents in fielded assays requires maintaining a high-quality and economical supply of these reagents…
Bioreactor productivities are highly dependent on the process used to cultivate mammalian cells. These productivities directly affect the manufacturing plant capacity, and thereby the economics of production of monoclonal antibodies (MAbs). Historically, companies have chosen bioreactor process strategies that emphasize simplicity of scale-up at the expense of productivity, and conducted manufacturing using well-characterized and relatively straightforward batch processes. Such processes have successfully produced small or moderate quantities (ranging from ~100 g to ~ 1 kg per lot) of the desired antibody. Given the anticipated demand for large-scale quantities of MAbs (and the high stakes for the companies investing in these new biological entities), it is worthwhile to revisit these past selection strategies and see if — and under what conditions — they remain optimal today…
Recombinant monoclonal antibodies (rMAbs) are the predominant biotherapeutic protein under development today. FDA requires the structure characterization if rMAbs and other recombinant proteins to grant marketing approval. Characterizing such complex, inherently heterogeneous molecules is a significant analytical challenge that requires a broad array of physico-chemical tests. This article reports the use of reversed phase high-performance liquid chromatography (RP-HPLC) with on-line electrospray ionization mass spectrometry (ESI-MS) to rapidly determine the glycoform composition and the heavy chain C-terminal lysine heterogeneity of an intact rMAb. In addition, a novel multidimensional chromatographic platform was developed to investigate the two-dimensional, size exclusion chromatography (HPSEC) separation of the rMAb followed by RP-HPLC (HPSEC-RP-HPLC) with on-line ESI-MS analysis. Such analyses can characterize, identify, and confirm the structure of an intact rMAb…