An "Fc-Silenced" IgG1 Format With Extended Half-Life Designed for Improved Stability.

Multiple mutation combinations in the IgG Fc have been characterized to tailor immune effector function or IgG serum persistence to fit desired biological outcomes for monoclonal antibody therapeutics. An unintended consequence of introducing mutations in the Fc (particularly the C2 domain) can be a reduction in biophysical stability which can correlate with increased aggregation propensity, poor manufacturability, and lower solubility. Herein, we characterize the changes in IgG conformational and colloidal stability when 2 sets of C2 mutations "TM" (L234F/L235E/P331S) and "YTE" (M252Y/S254T/T256E) are combined to generate an antibody format lacking immune receptor binding and exhibiting extended half-life.