A U.S. Patent for a “Method of Protein Manufacture” was awarded to UCB Biopharma on April 21st, 2020. The present invention is a method for manufacturing an antigen-binding fragment of an antibody coupled to a polyethylene glycol (PEG) molecule, comprising: a) culturing prokaryotic host cells under conditions such that the cells express the antigen-binding fragment of an antibody, b) purifying said antigen-binding fragment from a mixture containing the host cells and other contaminants, wherein said purification comprises at least two chromatography steps and wherein a reducing agent is added to said mixture… Learn More