Non-affinity purification of proteins

1. A method for purifying a target protein from a mixture containing a host cell protein, consisting essentially of subjecting said mixture to:

(a) a first non-affinity purification step, and

(b) a second non-affinity purification step, followed by

(c) high-performance tangential-flow filtration (HPTFF), and

(d) isolating said protein in a purity containing less than 100 parts per million (ppm) of said host cell protein, wherein said method includes no affinity purification step.

2. The method of claim 1 wherein said first and second non-affinity purification steps are different and are selected from the group consisting of ion exchange chromatography and hydrophobic interaction chromatography.

3. The method of claim 2 wherein said ion exchange chromatography is selected from the group consisting of cation exchange chromatography, anion exchange chromatography and mixed mode ion exchange chromatography.

4. The method of claim 3 wherein said first and second affinity purification steps are cation exchange chromatography and anion exchange chromatography, in either order.

5. The method of claim 3 wherein said first non-affinity purification step is cation exchange chromatography and said second non-affinity purification step is anion exchange chromatography.

6. The method of claim 5 wherein said method consists of purification steps (a)-(c) followed by isolation step (d).

7. The method of claim 5 wherein said cation exchange chromatography step is performed on a cation exchange resin selected from the group consisting of a carboxy-methyl cellulose resin, a mixed mode ion exchange resin, sulphopropyl immobilized on agarose, and sulphonyl immobilized on agarose.

8. The method of claim 5 wherein said anion exchange ligand is selected from the group consisting of diethylaminoethyl (DEAE) and quaternary ammonium ions.

9. The method of claim 1 wherein the HPTFF is performed using a charged membrane.

10. The method of claim 1 wherein said host cell protein is Chinese Hamster Ovary Protein (CHOP).

11. The method of claim 1 wherein said target protein is an antibody.

12. The method of claim 11 wherein said antibody is a monoclonal antibody.

13. The method of claim 11 wherein said antibody is a polyclonal antibody.

14. The method of claim 11 wherein said antibody is a humanized antibody.

15. The method of claim 11 wherein said antibody is a human antibody.

16. The method of claim 11 wherein said antibody is an antibody fragment.

17. The method of claim 11 wherein said antibody fragment is selected from the group consisting of Fab, Fab′, F(ab′) 2 and Fv fragments, single-chain antibody molecules, diabodies, linear antibodies, bispecific antibodies and multispecific antibodies formed from antibody fragments.

18. The method of claim 11 wherein said antibody specifically binds to an antigen selected from the group consisting of CD3, CD4, CD8, CD19, CD20, CD34, CD40, EGF receptor, HER2, HER3, HER4 receptor, LFA-1, Mac1, p150,95, VLA-4, ICAM-1, VCAM, av/b3 integrin, CD11a, CD18, CD11b, VEGF, IgE, flk2/flt3 receptor, obesity (OB) receptor, mpl receptor, CTLA-4, and polypeptide C.

19. The method of claim 11 wherein said antibody is selected from the group consisting of anti-HER2; anti-CD20; anti-IL-8; anti-VEGF; anti-PSCA; anti-CD11a; anti-IgE; anti-Apo-2 receptor; anti-TNF-ÿ; anti-Tissue Factor (TF); anti-CD3; anti-CD25; anti-CD34; anti-CD40; anti-tac; anti-CD4; anti-CD52; anti-Fc receptor; anti-carcinoembryonic antigen (CEA)antibodies; antibodies directed against breast epithelial cells; antibodies that bind to colon carcinoma cells; anti-CD33; anti-CD22; anti-EpCAM; anti-GpIIb/IIIa; anti-RSV; anti-CMV; anti-HIV; anti-hepatitis; anti-ÿvÿ; anti-human renal cell carcinoma; anti-human 17-1A; anti-human colorectal tumor; anti-human melanoma; anti-human squamous-cell carcinoma; and anti-human leukocyte antigen (HLA) antibodies.

20. The method of claim 11 wherein said antibody is selected from the group consisting of anti-HER2 receptor, anti-VEGF, anti-IgE, anti-CD20, anti-CD 11a, and anti-CD40antibodies.

21. The method of claim 1 wherein the target protein is an immunoadhesin.

22. The method of claim 1 wherein the target protein is an antibody-like molecule.

23. The method of claim 22 wherein said antibody-like molecule is a protein fused to, or conjugated with, a C H 2/C H 3 region.

24. The method of claim 23 wherein said protein is selected from the group consisting of renin; growth hormones; growth hormone releasing factor; parathyroid hormone; thyroid stimulating hormone; lipoproteins; alpha-1-antitrypsin; insulin A-chain; insulin B-chain; proinsulin; follicle stimulating hormone; calcitonin; luteinizing hormone; glucagon; factor VIIIC; factor IX; tissue factor; von Willebrands factor; Protein C; atrial natr iuretic factor; lung surfactant; urokinase; human urine and tissue-type plasminogen activator (t-PA); bombesin; thrombin; hemopoietic growth factor; tumor necrosis factor-alpha and -beta; enkephalinase; RANTES; human macrophage inflammatory protein (MIP-1-alpha); serum albumins; Muellerian-inhibiting substance; relaxin A-chain; relaxin B-chain; prorelaxin; mouse gonadotropin-associated peptide; beta-lactamase; DNase; IgE; cytotoxic T-lymphocyte associated antigens (CTLAs); inhibin; activin; vascular endothelial growth factor (VEGF); receptors for hormones or growth factors; Protein A or D; rheumatoid factors; bone-derived neurotrophic factor (BDNF); neurotrophin-3, -4, -5, and -6 (NT-3, NT-4, NT-5, and NT-6), nerve growth factors; platelet-derived growth factor (PDGF); fibroblast growth factors; epidermal growth factor (EGF); transforming growth factors (TGF); insulin-like growth factor-I and -II (IGF-I and IGF-II; des(1-3)-IGF-I (brain IGF-I), insulin-like growth factor binding proteins (IGFBPs); CD proteins; erythropoietin; osteoinductive factors; immunotoxins; bone morphogenetic proteins (BMPs); interferons-alpha, -beta, and -gamma; colony stimulating factors (CSFs); interleukins IL-1 to IL-10; superoxide dismutase; T-cell receptors; surface membrane proteins; decay accelerating factor; viral antigens; transport proteins; homing receptors; addressins; regulatory proteins; integrins; tumor associated antigens; and fragments and thereof.

25. The method of claim 1 , further comprising the step of incorporating the isolated protein into a phannaceutical formulation.