Directed evolution has profoundly changed the way antibodies or antigen binding fragments (Fab) are produced today. Lead generation for product candidates is oftentimes based on complex combinatorial libraries containing a large collection of variant antibodies. The selection of candidate molecules by screening procedures like phage display is considered the gold standard. One major advantage of these methods is that initial candidate molecules can be further improved in terms of affinity, specificity, etc. by reiterative in vitro maturation processes using the very methods that have been used for lead generation…
Tag: <span>recombinant antibodies</span>
Regulatory agencies such as the FDA require the structure and amino acid sequence characterization of recombinant monoclonal antibodies (MAbs) to grant marketing approval. Characterizing such complex, inherently heterogeneous molecules is a significant analytical challenge that requires a broad array of physicochemical tests. Mass spectrometry (MS) is an essential tool for characterizing protein identity, functions, substrate specificity and amino acid sequence (AAS) of recombinant MAb biotherapeutics as it complements, or in some cases supersedes the utility of traditional biological methods. For some of the most important proteomic applications, the high sensitivity and accuracy provided by modern MS has allowed the unequivocal protein characterization…
The approval of a new biological drug for therapeutic use requires supporting data from a variety of studies, including those that demonstrate the suitability of the manufacturing process. The regulatory guidance advocates that one of these studies address the issue of cell substrate stability by testing for consistent production of the product of interest by a characterised cell bank, generally the working cell bank (WCB). The study should evaluate stability during cultivation for production by examining a minimum of two time points — at a minimal number of population doublings and at or beyond the limit of in vitro cell age for production. The guidelines state that, “Evaluation of the cell substrate with respect to the consistent production of the intended product of interest should be the primary subject of concern”…
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…
Monoclonal antibodies constitute a significant percentage of the protein-based therapeutic molecules currently in clinical trials. The broad applicability and proven commercial success for this class of molecules suggest a larger future market potential. The current biopharmaceutical manufacturing capacity is widely anticipated to be a rate-limiting factor in the growth of the biotech sector. Because antibody therapeutics represent such a large part of this market, and because the therapeutic dosages of antibodies tend to be greater than most biopharmaceuticals, there is an immediate need for novel antibody manufacturing approaches that deliver significantly greater productivity…
Organizations developing biopharmaceuticals are often faced with the challenge of developing, as rapidly as possible, a production system for a recombinant protein or antibody intended for use in clinical trials. For expression of antibodies and other proteins with complex post-translational modifications, Chinese hamster ovary (CHO) cells are often the host of choice. However, isolation of CHO cell lines producing even moderate levels of a protein of interest is usually a lengthy process due to the need for at least one and usually several gene amplification steps. Gene amplification, which is usually accomplished through the dihydrofolate reductase (dhfr)/methotrexate system, is a requirement for most CHO expression vectors because the absolute expression level from each copy of an integrated expression plasmid is generally very low…