Dual drug antibody-drug conjugates

A functionalized antibody protein comprising an N-linked oligosaccharide, wherein the oligosaccharide comprises a conjugated first cargo moiety and a conjugated second cargo moiety that is different from the first cargo moiety, and wherein the N-linked has the formula:

• wherein:
• P represents the protein;
• R1 is independently selected from hydrogen or fucose;
• n is 0 or 1;
• Rg is selected from hydrogen or GlcNAc;
• R3 represents the conjugated first cargo moiety comprising an oligosaccharide comprising a first terminal sialoside, wherein said first terminal sialoside has the formula:
• wherein Ra is independently selected from —OH or *-L1-(A1)a, and Rb is independently selected from —H or *-L1-(A1)a, wherein L1 represents a first linker, A1 represents a first cargo compound, and a is 1 or 2, provided at least one *-L1-(A1)a group is present;
• and
• R6 represents the conjugated second cargo moiety comprising an oligosaccharide comprising a second terminal sialoside, said second terminal sialoside having the formula:
• wherein Rc is independently selected from —OH or *-L2-(A2)b, and Rd is independently selected from —H or *-L2-(A2)b, wherein L2 represents a second linker, A2 represents a second cargo compound, and b is 1 or 2, provided at least one *-L2-(A2)b group is present.