The research-grade biosimilar is an antibody-drug conjugate that is directed to CD22 which is highly expressed on the surface of B cells. The conjugate consists of Anti-CD22 humanised monoclonal antibody that is linked to a cytotoxic drug N-acetyl-gamma-calicheamicin via 4-(4 acetylphenoxy) butanoic acid (acetyl butyrate) linker. Upon internalisation in the cell, the drug is detached from the antibody by hydrolytic cleavage. The drug binds to the minor groove of the DNA and forms a diradical species. This diradical species abstracts hydrogen ions from the phosphodiester bonds of DNA and causes double-strand DNA breaks, which leads to cell cycle arrest and apoptosis of the tumorigenic cells. The original antibody-drug conjugate is approved by the FDA to treat acute myeloid leukemia. It is also approved to treat adults with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL).
In PBS, pH 7.5