Abstract: The invention relates to a method of preparing a protein formulation including a therapeutic protein, the method comprising the steps of: providing a solution comprising said protein; concentrating the protein in the solution by a first ultra-filtration step; diafiltering the solution with a diafiltration buffer including at least one first excipient, whereby a retentate is obtained comprising the protein and the first excipient; further concentrating the protein in the retentate by a second ultra-filtration step; and adding at least one final excipient, whereby the protein formulation with a desired protein concentration is obtained. According to the inven tion, the method further comprises, before the second ultra-filtration step, adding a second excipient to the retentate obtained from the diafiltration step. The invention is also directed to antibody formulations produced by the foregoing method.

Abstract: The present invention provides, among other things, methods of purifying or recovering proteins, in particular, small modular immunopharmaceutical (SMIPs™) proteins, from protein preparations containing high molecular weight (HMW) aggregates and other impurities based on hydroxyapatite chromatography. In some embodiments, the hydroxyapatite chromatography is used in combination with affinity chromatography and/or ion exchange chromatography. In some embodiments, inventive methods according to the invention involve no more than three chromatography steps. The present invention also provides proteins such as SMIPs™ purified according to the invention and pharmaceutical compositions containing the same.