CL2A is a pH-sensitive, cleavable PEG8- and triazole-containing PABC-peptide-mc linker, characterized by its ability to induce a bystander effect. It forms a disulfide bond with an antibody at a cysteine residue. Labetuzumab govitecan utilizes this linker for its drug conjugation[1].
CL2 Linker is a cleavableADC linker. CL2-SN-38 and CL2A-SN-38 are equivalent in drug substitution (~6), cell binding (Kd ~1.2 nM), cytotoxicity (IC50 ~2.2 nM), and serum stability in vitro (t1/2 ~20 hours)[1][2].