Calicheamicin antibody drug conjugates linking an amidoacetyl group to a sugar moiety on calicheamicin

An ADC comprising a structure of Formula II

• AbL1-L2-D)n (II)
• or a pharmaceutically acceptable salt thereof, wherein:
• Ab is a monoclonal antibody;
• L1-L2together are a linker selected from the group consisting of:
• wherein the wavy line indicates a point of attachment to an Ab;
• L2 is a linker;
• wherein L2 is selected from the group consisting of an amino acid, a peptide, —(CH2)m—, —(CH2CH2O)m—, PAB, Val-Cit-PAB, Val-Ala-PAB, Ala-Ala-Asn-PAB, and combinations thereof, wherein m is an integer from 0 to 10;
• D is calicheamicin;
• and
• n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.