Patent ID: 8716446

Claim:
A conjugate comprising a mutant human IL-11 (mIL-11) and a biocompatible polymer; wherein said mIL-11 comprises the amino acid sequence of SEQ ID NO:2, except for five or fewer amino acid substitutions, provided that the amino acid residue corresponding to position 1 of SEQ ID NO:2 is alanine and the amino acid residue corresponding to position 125 of SEQ ID NO:2 is asparagine; wherein the level of cell proliferation activity in vitro of said conjugate is at least 95% of the level of cell proliferation activity of an unconjugated reference mIL-11, where the amino acid sequences of the mIL-11 in the conjugated mIL-11 and in the unconjugated reference mIL-11 are identical; and wherein said cell proliferation activity is determined by contacting said conjugate or said unconjugated reference mIL-11 to cells responsive to IL-11, cultivating said cells in vitro, and measuring the resulting cell proliferation.