Recombinant monoclonal antibodies have during the last two decades emerged as a very successful class of biological drugs for the treatment of a variety of different diseases used either as biological mono therapy or in combination with small molecule based drugs. Recombinant antibody mixtures offering targeting of more than one antigen is one of the new promising antibody technologies resulting in higher therapeutic effectiveness and/or broader reactivity. Such recombinant antibody mixtures can in principle be manufactured by different approaches but two main strategies is often applied, either individual manufacturing of the constituent antibodies or single batch manufacturing of the recombinant antibody mixture. Symphogen has developed an expression platform, Sympress™, allowing single batch manufacturing of recombinant antibody mixtures, while other companies are currently using a manufacturing strategy based on production of the individual constituent monoclonal antibodies. An overview and comparison of the different approaches with focus on the challenges in terms of cell banking strategy, manufacturing approach, and strategies for release and characterization will be reviewed in the present manuscript. Furthermore, the two manufacturing approaches are compared based on different parameters such as development timelines, preclinical developmental costs, and manufacturing cost of goods sold (COGS). We conclude that the single batch manufacturing approach expressing a mixture of full length IgG provides a robust and reproducible platform that can be used for cost effective manufacturing of recombinant antibody mixtures.
", upstream processes including the establishment , characterization and validation of master Agrobacterium banks especially under current Good Manufacture Practices ( cGMP ) regulations can also incur substantial cost for their production . For example , one typical mammalian cell bank for MAb costs approximately $ 350 000 – 500 000 to establish ( Rasmussen et al . , 2012 ) . The manufacturing cost for establishing a cGMP master Agrobacte - rium bank is assumed to be less expensive than that of mammalian cells due to the reduced cost in fermenter and culture media ; however , it still incurs the equivalent labour and regulatory compliance costs in characterizing and validating the identity , stability an"
[Show abstract][Hide abstract] ABSTRACT: Previously, our group engineered a plant-derived monoclonal antibody (MAb pE16) that efficiently treated West Nile virus (WNV) infection in mice. In this study, we developed a pE16 variant consisting of a single-chain variable fragment (scFv) fused to the heavy chain constant domains (CH) of human IgG (pE16scFv-CH). pE16 and pE16scFv-CH were expressed and assembled efficiently in Nicotiana benthamiana ∆XF plants, a glycosylation mutant lacking plant-specific N-glycan residues. Glycan analysis revealed that ∆XF plant-derived pE16scFv-CH (∆XFpE16scFv-CH) and pE16 (∆XFpE16) both displayed a mammalian glycosylation profile. ∆XFpE16 and ∆XFpE16scFv-CH demonstrated equivalent antigen-binding affinity and kinetics, and slightly enhanced neutralization of WNV in vitro compared with the parent mammalian cell-produced E16 (mE16). A single dose of ∆XFpE16 or ∆XFpE16scFv-CH protected mice against WNV-induced mortality even 4 days after infection at equivalent rates as mE16. This study provides a detailed tandem comparison of the expression, structure and function of a therapeutic MAb and its single-chain variant produced in glycoengineered plants. Moreover, it demonstrates the development of anti-WNV MAb therapeutic variants that are equivalent in efficacy to pE16, simpler to produce, and likely safer to use as therapeutics due to their mammalian N-glycosylation. This platform may lead to a more robust and cost-effective production of antibody-based therapeutics against WNV infection and other infectious, inflammatory or neoplastic diseases.
"For example, it has been reported that rabbit derived anti-thymocyte globulin (ATG) causes serum sickness in patients in several clinical applications [9,10]. Recently, an in vitro antibody production system based on recombinant DNA and mammalian cell culture technologies has been in the development by Symphogen A/S . This approach tries to mimic polyclonal nature of humoral immune response by producing mixtures of monoclonal antibodies (mAbs) that recognize multiple epitopes of an antigen. "
[Show abstract][Hide abstract] ABSTRACT: Therapeutic human polyclonal antibodies (hpAbs) derived from pooled plasma from human donors are Food and Drug Administration approved biologics used in the treatment of a variety of human diseases. Powered by the natural diversity of immune response, hpAbs are effective in treating diseases caused by complex or quickly-evolving antigens such as viruses. We previously showed that transchromosomic (Tc) cattle carrying a human artificial chromosome (HAC) comprising the entire unrearranged human immunoglobulin heavy-chain (hIGH) and kappa-chain (hIGK) germline loci (named as κHAC) are capable of producing functional hpAbs when both of the bovine immunoglobulin mu heavy-chains, bIGHM and bIGHML1, are homozygously inactivated (double knockouts or DKO). However, B lymphocyte development in these Tc cattle is compromised, and the overall production of hpAbs is low. Here, we report the construction of an improved HAC, designated as cKSL-HACΔ, by incorporating all of the human immunoglobulin germline loci into the HAC. Furthermore, for avoiding the possible human-bovine interspecies incompatibility between the human immunoglobulin mu chain protein (hIgM) and bovine transmembrane α and β immunoglobulins (bIgα and bIgβ) in the pre-B cell receptor (pre-BCR) complex, we partially replaced (bovinized) the hIgM constant domain with the counterpart of bovine IgM (bIgM) that is involved in the interaction between bIgM and bIgα/Igβ; human IgM bovinization would also improve the functionality of hIgM in supporting B cell activation and proliferation. We also report the successful production of DKO Tc cattle carrying the cKSL-HACΔ (cKSL-HACΔ/DKO), the dramatic improvement of B cell development in these cattle and the high level production of hpAbs (as measured for the human IgG isotype) in the plasma. We further demonstrate that, upon immunization by tumor immunogens, high titer tumor immunogen-specific human IgG (hIgG) can be produced from such Tc cattle.
PLoS ONE 10/2013; 8(10):e78119. DOI:10.1371/journal.pone.0078119 · 3.23 Impact Factor
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