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Antibody Therapeutics (antibody + therapeutics)
Selected AbstractsIncreasing the activity of monoclonal antibody therapeutics by continuous chromatography (MCSGP)BIOTECHNOLOGY & BIOENGINEERING, Issue 4 2010T. Müller-Späth Abstract The charged monoclonal antibody (mAb) variants of the commercially available therapeutics Avastin®, Herceptin® and Erbitux® were separated by ion-exchange gradient chromatography in batch and continuous countercurrent mode (MCSGP process). Different stationary phases, buffer conditions and two MCSGP configurations were used in order to demonstrate the broad applicability of MCSGP in the field of charged protein variant separation. Batch chromatography and MCSGP were compared with respect to yield, purity, and productivity. In the case of Herceptin®, also the biological activity of the product stream was taken into account as performance indicator. The robustness of the MCSGP process against feed composition variations was confirmed experimentally and by model simulations. Biotechnol. Bioeng. 2010;107:652,662. © 2010 Wiley Periodicals, Inc. [source] Crystallization of IgG1 by mapping its liquid,liquid phase separation curvesBIOTECHNOLOGY & BIOENGINEERING, Issue 5 2006Adam Idu Jion Abstract Monoclonal antibody therapeutics is an important and fast expanding market. While production of these molecules has been a major area of research, much less is known regarding the stabilization of these proteins for delivery as drugs. Crystallization of antibodies is one such promising route for protein stabilization at high titers, and here we took a systematic approach to initiate crystallization through nucleation in a simple PEG (polyethylene glycol), protein in water solution. A ternary mixture of globular proteins, PEG, and water will undergo a liquid,liquid phase separation (LLPS) as shown in a phase diagram or a Binodal curve. Of particular interest within the phase diagram is the position of the critical point, which is where nucleation occurs most rapidly. Detailed LLPS maps were created by increasing concentrations of PEG (from 5% to 11%) and IgG (from 1 to 20 mg/mL). By increasing the molecular weight (MW) of PEG (and hence its radius of gyration) from 1,000 to 6,000 g/mol, the temperatures of the critical point of nucleation were shown to increase. Once these curves were determined, nucleation experiments were conducted close to a chosen critical point (10.5 mg/mL IgG in 11% PEG 1000) and after 3 weeks, crystals of IgG of approximately 100 ,m in size were successfully formed. This is the first example of crystallization of an antibody through systematic mapping of LLPS curves, which is a fundamental step towards the scale-up of antibody crystallization. © 2006 Wiley Periodicals, Inc. [source] Salt tolerant membrane adsorbers for robust impurity clearanceBIOTECHNOLOGY PROGRESS, Issue 6 2009William T. Riordan Abstract Clearance of impurities such as viruses, host cell protein (HCP), and DNA is a critical purification design consideration for manufacture of monoclonal antibody therapeutics. Anion exchange chromatography has frequently been utilized to accomplish this goal; however, anion exchange adsorbents based on the traditional quaternary amine (Q) ligand are sensitive to salt concentration, leading to reduced clearance levels of impurities at moderate salt concentrations (50,150 mM). In this report, membrane adsorbers incorporating four alternative salt tolerant anion exchange ligands were examined for impurity clearance: agmatine, tris-2-aminoethyl amine, polyhexamethylene biguanide (PHMB), and polyethyleneimine. Each of these ligands provided greater than 5 log reduction value (LRV) for viral clearance of phage ,X174 (pI , 6.7) at pH 7.5 and phage PR772 (pI , 4) at pH 4.2 in the presence of salt. Under these same conditions, the commercial Q membrane adsorber provided no clearance (zero LRV). Clearance of host-cell protein at pH 7.5 was the most challenging test case; only PHMB maintained 1.5 LRV in 150 mM salt. The salt tolerance of PHMB was attributed to its large positive net charge through the presence of multiple biguanide groups that participated in electrostatic and hydrogen bonding interactions with the impurity molecules. On the basis of the results of this study, membrane adsorbers that incorporate salt tolerant anion exchange ligands provide a robust approach to impurity clearance during the purification of monoclonal antibodies. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] Antibodies and Genetically Engineered Related Molecules: Production and PurificationBIOTECHNOLOGY PROGRESS, Issue 3 2004A. Cecília A. Roque Antibodies and antibody derivatives constitute 20 % of biopharmaceutical products currently in development, and despite early failures of murine products, chimeric and humanized monoclonal antibodies are now viable therapeutics. A number of genetically engineered antibody constructions have emerged, including molecular hybrids or chimeras that can deliver a powerful toxin to a target such as a tumor cell. However, the general use in clinical practice of antibody therapeutics is dependent not only on the availability of products with required efficacy but also on the costs of therapy. As a rule, a significant percentage (50,80%) of the total manufacturing cost of a therapeutic antibody is incurred during downstream processing. The critical challenges posed by the production of novel antibody therapeutics include improving process economics and efficiency, to reduce costs, and fulfilling increasingly demanding quality criteria for Food and Drug Administration (FDA) approval. It is anticipated that novel affinity-based separations will emerge from the development of synthetic ligands tailored to specific biotechnological needs. These synthetic affinity ligands include peptides obtained by synthesis and screening of peptide combinatorial libraries and artificial non-peptidic ligands generated by a de novo process design and synthesis. The exceptional stability, improved selectivity, and low cost of these ligands can lead to more efficient, less expensive, and safer procedures for antibody purification at manufacturing scales. This review aims to highlight the current trends in the design and construction of genetically engineered antibodies and related molecules, the recombinant systems used for their production, and the development of novel affinity-based strategies for antibody recovery and purification. [source] | ||||||||||