Alternative molecular formats and therapeutic applications for bispecific antibodies

Abstract

Bispecific antibodies are on the cusp of coming of age as therapeutics more than half a century after they were first described. Two bispecific antibodies, catumaxomab (Removab(®), anti-EpCAM×anti-CD3) and blinatumomab (Blincyto(®), anti-CD19×anti-CD3) are approved for therapy, and >30 additional bispecific antibodies are currently in clinical development. Many of these investigational bispecific antibody drugs are designed to retarget T cells to kill tumor cells, whereas most others are intended to interact with two different disease mediators such as cell surface receptors, soluble ligands and other proteins. The modular architecture of antibodies has been exploited to create more than 60 different bispecific antibody formats. These formats vary in many ways including their molecular weight, number of antigen-binding sites, spatial relationship between different binding sites, valency for each antigen, ability to support secondary immune functions and pharmacokinetic half-life. These diverse formats provide great opportunity to tailor the design of bispecific antibodies to match the proposed mechanisms of action and the intended clinical application.

Influence of Escherichia coli chaperone DnaK on protein immunogenicity

“…For example, in 2015 the world's top selling drug was AbbVie's monoclonal antibody Humira (adalimumab) 1. Biopharmaceuticals, including many antibody fragments that are currently in development,2, 3 are primarily produced in non‐human host cells, including Escherichia coli , rodent cell lines and yeast 4. During purification it is well established that small amounts of host cell protein (HCP), including intracellular proteins, will co‐purify with the production biopharmaceutical 5.…”

Heavy and light chain pairing of bivalent quadroma and knobs-into-holes antibodies analyzed by UHR-ESI-QTOF mass spectrometry

“…Not only are these antibodies able to bind to 2 different antigens such as 2 cell surface proteins or 2 ligands, they are also able to, for example, simultaneously bind to tumor proteins and cytotoxic T-cells, thus directing therapeutic agents to the intended target (for recent reviews, see Riethm€ uller, 1 Kontermann, 2 and Spiess et al 3 ). Among the first attempts to produce such compounds, the so-called "Quadroma" approach has been used, where 2 antibody-secreting cell lines were combined by somatic fusion.…”

EFab domain substitution as a solution to the light-chain pairing problem of bispecific antibodies

“…1,2 Therefore, efficient methods of generating bispecific antibodies are being pursued. Initial attempts to produce bsAbs as protein therapeutics involved chemical conjugation of monospecific antibodies and fusion of monoclonal antibody (mAb)-expressing cells, 3,4 but low efficiency and the necessity of purification from abundant side products limited the widespread use of these strategies.…”

“…Advancements in protein engineering and molecular biology have enabled the generation of a variety of new bsAb formats, and more than 60 such formats have been described in the literature. 1,2 However, the altered biochemical/biophysical properties, serum half-life, and/or stability of these engineered bsAb formats can sometimes render them unsuitable as a therapeutic. Thus, new technologies for the generation of bsAbs are still being developed.…”