US 11,964,998 B2
Method for purifying anti-IL-6 receptor antibodies
Harry-James Sutter, Vevey (CH); and Xavier Le Saout, Clarens (CH)
Assigned to FRESENIUS KABI DEUTSCHLAND GMBH, Bad Homburg (DE)
Appl. No. 16/635,134
Filed by FRESENIUS KABI DEUTSCHLAND GMBH, Bad Homburg (DE)
PCT Filed Aug. 30, 2018, PCT No. PCT/EP2018/073345
§ 371(c)(1), (2) Date Jan. 29, 2020,
PCT Pub. No. WO2019/043096, PCT Pub. Date Mar. 7, 2019.
Claims priority of application No. 17188660 (EP), filed on Aug. 30, 2017.
Prior Publication US 2020/0165295 A1, May 28, 2020
Int. Cl. C07K 1/16 (2006.01); B01D 15/38 (2006.01); C07K 1/22 (2006.01); C07K 1/36 (2006.01); C07K 16/06 (2006.01); C07K 16/24 (2006.01); C07K 16/28 (2006.01)
CPC C07K 1/165 (2013.01) [B01D 15/3809 (2013.01); C07K 1/22 (2013.01); C07K 16/065 (2013.01); C07K 16/248 (2013.01); C07K 16/2866 (2013.01); C07K 2317/24 (2013.01)] 8 Claims
 
1. A method of purifying a mono-specific anti-IL-6 receptor antibody from a sample containing said antibody and impurities, wherein the anti-IL-6 receptor antibody is tocilizumab, the impurities comprise host cell proteins, aggregates of the anti-IL-6 receptor antibody and fragments of the anti-IL-6 receptor antibody, and the method comprises the following steps:
(a) contacting the sample containing the antibody and the impurities with a protein A chromatography material under conditions such that the antibody binds to the protein A chromatography material and at least a portion of the impurities does not bind to the protein A chromatography material;
(b) eluting the antibody from the Protein A chromatography material, in order to obtain an eluate;
(c) loading the eluate of step (b) onto a first mixed mode chromatography material under conditions such that the antibody does not bind to the first mixed mode chromatography material and at least a portion of the remaining impurities binds to the first mixed mode chromatography material, wherein the first mixed mode chromatography material is a N-benzyl-N-methyl ethanol amine ligand;
(d) recovering the flowthrough containing the antibody under conditions such that said recovered flowthrough contains a lower level of impurities than the eluate of step (b),
(e) loading the recovered flowthrough containing the antibody of step (d) onto a second mixed mode chromatography material under conditions such that the antibody does not bind to the second mixed mode chromatography material and at least a portion of the remaining impurities binds to the second mixed mode chromatography material; wherein the second mixed mode chromatography material is a fluorapatite-based ligand of ceramic fluoroapatite type I or ceramic fluoroapatite type II; and
(f) recovering the flowthrough containing the antibody under conditions such that said recovered flowthrough contains a lower level of impurities than the recovered flowthrough of step (d).