The invention provides buffered aqueous formulations of bevacizumab. The formulations comprise a citrate phosphate buffer comprising trehalose or sucrose, and polysorbate 20. The formulations have an acidic pH of from about 5.8 to about 6.0, and enhance the conformational and colloidal stability of the bevacizumab molecule. Levels of potency-reducing reversible aggregates and covalent dimers in the citrate phosphate buffer were low, and this buffer further offered protection against storage stress, but did not modify or alter any key biophysical descriptor of the antibody.
