Eshmuno® CPX resin is a new strong cation exchanger developed using EMD Millipore’s tentacle technology to provide high binding capacity, resolution, and target yield. For process improvement purposes, this resin was applied for capture of rhFGF18, a fibroblast growth factor (expressed in Escherichia coli) in phase 2 clinical development for restoring damaged cartilage surface in osteoarthritis. Early purification work used Resin A at low load (12.3 mg target/mL CV) and moderate flow rate (180 cm/h = 6.7 min residence time,…