Category Archives: add

Main elements of antibody-drug conjugate (ADC): Toxins/Payloads (Classification and function)

There are so many payloads, like MMAE, Calicheamicin, MMAF, DM1, SN-38 and Dxd. Microtubule destroying drug 1. Calendula Auristatins is an important payload used in ADC. The most famous family member MMAE exists in two listed drugs, adcetris and Polivy. At present, more than 10 kinds of ADCs with calendula (such as MMAE) or methylcalendula […]

Main elements of antibody-drug conjugate (ADC): Linker (cleavable/non-cleavable, structure and mechanism)

Table2. Chemical triggers Conjugate linker is not only the molecular part forming covalent connection between antibody and small molecule payload, but also the key element with design properties in targeted drug therapy. The addition of linkers should not induce aggregation, and it is necessary to ensure acceptable PK characteristics, limit the premature release (stability) of […]

Main elements of antibody-drug conjugate (ADC): Antibodies and their targets

1. Mylotarg® (gemtuzumab ozogamicin) from Wyeth/Pfizer was the first ADC to reach the market. It is composed of a recombinant humanized anti-CD33 mAb (IgG4κ antibody hP67.6) covalently attached to a calicheamicin derived payload (N-acetyl-γ-calicheamicin 1,2-dimethyl hydrazine dichloride) via a pH-sensitive hydrazone linker. 2. Adcetris® (brentuximab vedotin) from Seagen (formerly Seattle Genetics), containing a CD30-specific mAb conjugated to […]

Format of bispecific antibodies (BsAbs)-Dual-affinity re-targeting antibody

Dual-affinity re-targeting proteins (DARTs) encompasses of two Fv fragments, containing two single antigen-binding sites formed when two Fv fragments heterodimerize. The Fv1 contains of a VH from antibody A and a VL from antibody B, whereas Fv2 contains VH from antibody B and VL from antibody A in the order of VL (1)-VH (2) and […]

Format of bispecific antibodies (BsAbs)-Tandem scFv

A tandem scFv links two or more scFvs with the helical peptide linkers in the orientation NH2–VL1–VH1–(linker–VL2–VH2)n–COOH, resulting in a single chain bivalent and bi-specific molecule encoded by a single gene (Figure 2). Tandem scFv can be used to target two different antigens on two different cells, two different antigens on the same cell, or […]

Format of bispecific antibodies (BsAbs)-Tandem VHH

Since 1975, monoclonal antibodies have been successfully used for the diagnosis and therapeutics. In 1993, heavy-chain-only antibodies which bind to antigens was discovered in camelids. The variable domain of heavy chain antibody (VHH) was called as nanobodies and it was anticipated as the better therapeutic antibodies in future due to its high stability, refoldability, and manipulable characteristics. […]

Format of bispecific antibodies (BsAbs)-Controlled Fab arm exchange

Controlled Fab arm exchange (cFAE) has proven to be a generic and versatile technology for the efficient generation of IgG-like bispecific antibodies (DuoBodies or DBs). This involves the recombination of antigen-binding arms (heavy chain–light chain (H-L) pairs) between individually expressed antibody molecules and is termed Fab-arm exchange, can be modified to make the routine generation […]

Format of bispecific antibodies (BsAbs)-Hetero heavy chain, Common light chain

Since an IgG antibody has two antigen-binding fragments (Fab) both of which link to an Fc region, there had long been a concept of an asymmetric bispecific IgG antibody capable of binding to two different antigens or epitopes. The asymmetric reengineering technology immunoglobulin (ART-Ig) is a humanized asymmetric bispecific IgG antibody. An asymmetric bispecific IgG […]

Format of bispecific antibodies (BsAbs)-Rat-mouse hybrid IgG

Rat-mouse hybrid IgG is a monoclonal antibody with binding sites for two different antigens, typically CD3 and a tumor antigen, making it a type of bispecific monoclonal antibody. In addition, its intact Fc-part can bind to an fc receptor on accessory cells like conventional monospecific antibodies. The net effect is that this type of drug […]

Format of bispecific antibodies (BsAbs)-(scFv)2-Fab

Tribodies are multifunctional recombinant antibody derivatives. The Fab fragment serves as a specific heterodimerization signal, and the two scFv fragments are each fused to a different Fab chain. In this way we obtain a molecule of intermediate molecular weight (100 kDa) which allows incorporating three different antibody fragments (Fig. 1). This manifold, tribody, can be […]