Patent ID: 7544738

Claim:
A polymer conjugate composition comprising a polymer conjugate prepared by reacting a water-soluble and non-peptidic polymer reagent composition with a biologically active agent to form the polymer conjugate composition, wherein the water-soluble and non-peptidic polymer reagent comprises a maleimide functional group and the water-soluble and non-peptidic polymer reagent is prepared by a method comprising the steps of (i) reacting a terminal hydroxyl group of a water-soluble and non-peptidic polymer bearing a terminal hydroxyl group with di(1-benzotriazolyl)carbonate to form a 1-benzotriazolylcarbonate ester of the water-soluble and non-peptidic polymer, (ii) reacting the 1-benzotriazolylcarbonate ester of the water-soluble and non-peptidic polymer with lysine to form a water-soluble and non-peptidic lysine derivative, and (iii) using the polymer lysine derivative in the formation of the water-soluble and non-peptidic reagent.