Monomethyl auristatin D (MMAD), a potent tubulin inhibitor, is a toxin payload in antibody drug conjugate; Mc-MMAD is a protective group (maleimidocaproyl) -conjugated MMAD. IC50 Value: Target: tubulin; ADCs For comparison purposes, the ADC A1 -mc-MMAD and/or A1 -vc-MMAD were used. The linker payload, mc-MMAD (6-maleimidocaproyl-monomethylauristatin-D) was conjugated to the A1 anti-5T4 monoclonal antibody through a cysteine residue at a ratio of approximately 4 drug moieties per antibody molecule. The linker payload mc- Val-Cit-PABA-MMAD or vc-MMAD (maleimidocapronic -valine-citruline-p- aminobenzyloxycarbonyl- monomethylauristatin-D) was conjugated to the A1 anti-5T4 monoclonal antibody through a cysteine residue at a ratio of approximately 4 drug moieties per antibody molecule (Antibody-drug conjugates Patent: WO 2013068874 A1).

• [1]. Antibody-drug conjugates Patent: WO 2013068874 A1