Recombinant approaches to IgG-like bispecific antibodies

Abstract

One of the major obstacles in the development of bispecific antibodies (BsAb) has been the difficulty of producing the materials in sufficient quality and quantity by traditional technologies, such as the hybrid hybridoma and chemical conjugation methods. In contrast to the rapid and significant progress in the development of recombinant BsAb fragments (such as diabody and tandem single chain Fv), the successful design and production of full length IgG-like BsAb has been limited. Compared to smaller fragments, IgG-like BsAb have long serum halflife and are capable of supporting secondary immune functions, such as antibody-dependent cellular cytotoxicity and complement-mediated cytotoxicity. The development of IgG-like BsAb as therapeutic agents will depend heavily on our research progress in the design of recombinant BsAb constructs (or formats) and production efficiency. This review will focus on recent advances in various recombinant approaches to the engineering and production of IgG-like BsAb.

CODV-Ig, a universal bispecific tetravalent and multifunctional immunoglobulin format for medical applications

“…For example, any format isolating a variable fragment (Fv) by replacing its adjacent constant fragment (Fc) with a peptide linking heavy or light chain Fv domains is associated with decreased Fv stability. 2,8 Introduction of disulfide bridges or improved interface interactions stabilize Fv dimerization in specific cases; however, such strategies remain associated with loss of antigen affinity or increased aggregation propensity. [9][10][11][12] Asymmetric bispecific antibodies including Fc domains give rise to improperly paired side-products even when optimized.…”

“…[9][10][11][12] Asymmetric bispecific antibodies including Fc domains give rise to improperly paired side-products even when optimized. 2 Thus, they generally require further engineering, extensive purification, or special production systems imposing specific limitations. 8,[13][14][15][16][17][18][19][20][21][22] Furthermore, their avidity per antigen is reduced compared to the parental antibodies.…”

“…Molecular weights range from »55 kDa to over 300 kDa, their valences for antigen binding are from two to six, and serum half-lives are reported to be between »0.5 hours and »2 weeks. 1,2,[5][6][7] Each format presents a particular strength in physicochemical properties, manufacturing, formulation, pharmacokinetics, or pharmacodynamics while being limited in the other evaluation criteria. 1 Sustained structural and functional homogeneity throughout manufacture, storage, and in vivo exposure is critical to their successful therapeutic application, but recognized in many bispecific formats as limiting factor.…”

“…1,2 Two bispecific antibody therapeutics, catumaxomab (Removab Ò ) and blinatumomab (Blincyto Ò ), have been approved, and over ten bispecific antibodies are currently in clinical development for treatment of inflammatory diseases, hemophilia A, or cancers. 3,4 The drug-like properties of bispecific biotherapeutics described in the literature vary widely.…”

Single Variable Domain-IgG Fusion

“…On the other hand, the successful design and production of full-length IgG-like, i.e. Fc domain-containing, BsAb has been generally limited (20,21). In this study, we describe a novel recombinant method for the production of an Fc domain-containing BsAb molecule by direct fusion of a single variable domain (sVD) antibody to the N terminus of the LC of a functional IgG antibody of a different specificity.…”