Patent ID: 7736635

Claim:
A compound of the following formula: wherein P 1 and P 2 independently represent a polyethylene glycol (PEG) moiety; Z 1 and Z 2 independently represent a polyclonal, monoclonal, multi-valent, multi-specific, humanized or chimeric antibody, a single chain antibody, a Fab fragment, a Fab′ or F(ab′) 2 fragment, or an epitope-binding fragment thereof; X 1 and X 2 independently represent N; A 1 and A 2 independently represent —NHCO—; B 1 and B 2 independently represent —CO—; V 1 and V 2 independently represent a covalent bond; W 1 and W 2 independently represent —(CH 2 ) w —; Y 1 and Y 2 independently represent —(CH 2 ) y —; L 1 and L 2 independently represent a maleimide moiety, each of which is covalently linked to Z 1 and Z 2 , respectively, and each of which is covalently linked through the maleimide nitrogen atom to Y 1 and Y 2 , respectively; M 1 represents —(CH 2 ) m —; w is 1 or 2; y is 1, 2, 3, 4, 5 or 6; and m is 2.