Antibody-drug conjugate (ADC) is a humanized or human monoclonal antibody conjugated to highly cytotoxic small molecules (payloads) through a chemical linker. It is a novel form of treatment with great potential to make a paradigm shift in cancer chemotherapy. Compared with traditional chemotherapy, this new antibody-based molecular platform can selectively deliver effective cytotoxic payloads to target cancer cells, thereby improving efficacy, reducing systemic toxicity, and having better pharmacokinetics (PK)/Pharmacodynamics (PD) and biodistribution. So far, 8 ADC drugs have been approved by the FDA, and about 164 ADCs are in clinical trials.
The difficulty of ADC technology development lies in linker technology. At present, the site-specific ADC technology generally conjugates antibodies with drug molecules specifically through the engineering of cysteine sites, unnatural amino acids, selenocysteine, and enzyme (glutamine, glycoengineering, FGE) coupling technologies.
BOS Sciences has its own site-specific linker technology platform. Site-specific linker technology can ensure that a certain number of drug molecules are site-specifically coupled to specific sites of antibodies, to ensure drug homogeneity and mass production stability to a large extent. In addition, the DAR value can also be accurately controlled at 2 or 4.
Site-specific ADCs technology not only makes it possible to study the effects of coupling on ADC pharmacodynamics at different sites but also can be widely used in the coupling of other molecules such as nuclides, immunotoxins, proteins, precursor enzymes with antibodies. The therapeutic effect and application of these conjugated drugs in drug development have been greatly improved.