Technical advancement in biochemistry and antibody engineering has brought about new platforms for therapeutic antibody development. Some of these engineered Ab formats that are currently in clinical use are discussed below.
BsAbs are artificially engineered mAbs that can bind to two epitopes. They can be a cost-effective alternative to combination therapy by targeting two different signaling pathways. The approach can also be used to effectively bind to a target cell and an immune cell to induce cytotoxic signaling. The currently approved BsAb formats are the full-length IgG-like asymmetric antibody and the single-chain variable fragment (scFv)-based Ab with no Fc fragment. Several other BsAb formats are under development and some in clinical evaluation phase.
ADCs are an effective method to broaden the therapeutic window of primary Abs. The mAb can be conjugated to a cytotoxin drug or radioactive element via a non-cleavable linker. This approach increases therapeutic potency hence low doses can suffice the required clinical efficacy.