Patent ID: 7947261

Claim:
A conjugate of the following structure: wherein: POLY 1 is a water-soluble polymer selected from the group consisting of poly(alkylene glycols), poly(vinyl pyrrolidone), poly(vinyl alcohol), polyoxazoline and poly(N-acryloylmorpholine); POLY 2 is a water-soluble polymer selected from the group consisting of poly(alkylene glycols), poly(vinyl pyrrolidone), poly(vinyl alcohol), polyoxazoline and poly(N-acryloylmorpholine); (a) is 0, 1, 2 or 3; (b) is 0, 1, 2 or 3; (e) is 0, 1, 2 or 3; (f 1 ) is 0, 1, 2 or 3; (g 1 ) is 0, 1, 2 or 3; (h) is 0, 1, 2 or 3; (j) is 0, 1, 2 or 3; Each R l is independently H or an organic radical selected from the group consisting of alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl and substituted aryl; X 1 , when present, is a first spacer moiety; X 2 , when present, is a second spacer moiety; X 5 , when present, is a fifth spacer moiety; X 6 , when present, is a sixth spacer moiety; X 7 , when present, is a seven spacer moiety; X 8 , when present, is an eight spacer moiety; R 1 is a branching moiety selected from the group consisting of wherein (p) is 1-10 and (q) is 1-10; and Active Agent is a residue of a pharmacologically active agent.