Hydroxyl-polymer-drug-protein conjugates

A drug conjugate is provided herein. The conjugate comprises a protein based recognition-molecule (PBRM) and a polymeric scaffold having one or more -LD-D, the PBRM being connected to the polymeric scaffold by LP, wherein the polymeric scaffold comprises a linear, branched or cyclic polymer having four or more -OH groups. Each occurrence of D is independently a therapeutic agent having a molecular weight ≦5 kDa. LD and LP are linkers connecting the therapeutic agent and PBRM to the polymeric scaffold respectively. Also disclosed are polymeric scaffolds useful for conjugating with a PBRM to form a polymer-drug-PBRM conjugate described herein, compositions comprising the conjugates, methods of their preparation, and methods of treating various disorders with the conjugates or their compositions.