CALICHEAMICIN ANTIBODY DRUG CONJUGATES LINKING AN AMIDOACETYL GROUP TO A SUGAR MOIETY ON CALICHEAMICIN

1 . An ADC comprising a structure of Formula II

AbL 1 -L 2 -D) n   (II)

or a pharmaceutically acceptable salt thereof, wherein:

Ab is a monoclonal antibody;

L 1 -L 2 together are a linker selected from the group consisting of:

wherein the wavy line indicates a point of attachment to an Ab;

L 2 is a linker; wherein L 2 is selected from the group consisting of an amino acid, a peptide, —(CH 2 ) m —, —(CH 2 CH 2 O) 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.

2 . The ADC of claim 1 , wherein D has the structure of Formula III

or a pharmaceutically acceptable salt thereof;

wherein the wavy line indicates the point of attachment to L 2 ; and

wherein R1 is selected from the group consisting of C1-C8 alkyl, —(CH 2 CH 2 O) n —, isopropyl, glucose, galactose, mannose, glucosamine, C1-C8 alkyl-OH, and combinations thereof, and

where n=1-30

3 . The ADC of claim 1 , or a pharmaceutically acceptable salt thereof, wherein R1 is selected from the group consisting of: isopropyl,

wherein the wavy line indicates a point of attachment to the sulfur on calicheamicin.

4 . The ADC of claim 1 , wherein the structure of Formula II has a structure selected from the group consisting of:

or a pharmaceutically acceptable salt thereof.

5 . The ADC of claim 1 , wherein the structure of Formula II has a structure selected from the group consisting of:

or a pharmaceutically acceptable salt thereof.

6 . A compound having the structure:

or a pharmaceutically acceptable salt thereof.

7 . The compound of claim 6 , wherein Ab is antibody of an IgG class that binds to a c-Met epitope with a binding affinity of at least 10 −6 M.