Antibody-drug conjugates

An antibody-drug conjugate (ADC) comprising a structure represented by Formula (I):

• [D2-L2-Cn2yG2-Ab-G1Cn1-L1-D1]x Formula (I)
• or a pharmaceutically acceptable salt thereof, wherein
• Ab is an antibody without glycans;
• G1 and G2 are each a glycan moiety;
• Cn1 and Cn2 are each a conjugation moiety;
• L1 and L2 are each a linker moiety;
• D1 and D2 are each a drug unit which may be the same or different;
• and
• x and y are independently an integer from 0 to 1, provided that x+y≠0,
• wherein the glycan moiety has a structure shown as,
• Formula (II-2b):
• wherein
• [Ab] indicates an attachment site for the antibody;
• and
• [Cn] indicates an attachment site for the conjugation moiety;
• wherein the conjugation moiety has a structure of Formula (III-1):
• wherein
• Q is a Y1+Y2 spacer, wherein Y1 and Y2 are independently selected from the group consisting of a direct bond, —(CH2)n—, —O—, —NH—, —C(O)—, —C(O)NH—, —NHC(O)—, —(CH2)nO—, —O(CH2)n—, —(CH2)n—C(O)—, —C(O)(CH2)n—, —(CH2)n—NH—, —NH—(CH2)n—, —(CH2)n—NHC(O)—, —C(O)(CH2)n—NHC(O)—, (CH2)nSCH2C(O)—, and —(CH2CH2O)m—;
• n is an integer from 1 to 8, inclusive;
• m is an integer from 1 to 4, inclusive;
• [G] indicates an attachment site for the glycan moiety;
• and
• [L] indicated an attachment site for the linker moiety;
• wherein the linker moiety has the structure of Formula (IV-1) or Formula (IV-2):
• wherein
• [Cn] indicates an attachment site for the conjugation moiety;
• [D] indicates an attachment site for the drug unit;
• and
• n is an integer from 0 to 6, inclusive.