(515ar) Development Of A Streamlined Process For Efficient Purification Of Reverse Chimeric (Murine IgG1) Monoclonal Antibodies

The use of monoclonal antibodies (MAbs) as therapeutic proteins has been rapidly increasing over the past decade. A significant number of therapeutic MAb programs (~ 25%) are developed using transgenic mice as an animal model for a disease or for second-species safety assessment studies. In those cases, to eliminate the potential for mouse antibody-human antibody (MAHA) development, significant quantities (ex. tens of grams) of reverse chimeric MAbs with murine IgG1 backbones are required. Purification of these murine IgG1 is challenging due to relatively low affinity and low dynamic binding capacity (< 5 mg/mL) and hence low productivity in protein A capture columns. Development work was executed to achieve a streamlined (i.e. cost- and time-effective) purification process. Goals of research were to identify a combination of processing conditions and resins to increasing affinity resin loading to greater than 5 g/L. Research was also performed to control host cell protein and aggregate levels in CEX product streams at reasonable resin loading (> 10 g/L). Productivity data (dynamic and effective binding capacity, as well as resin capacity as a function of residence time) of various affinity chromatography resins will be reviewed. Cation exchange chromatography (CEX) conditions will be optimized for impurity clearance as a function of conductivity and pH. We will also discuss product stability (as measured by formation of higher-order aggregates) as a function of concentration and final formulation buffer composition.