Methods for reducing host cell protein content in antibody purification processes and antibody compositions having reduced host cell protein content

A pharmaceutical composition comprising an antibody that binds to human N3pGlu Aβ (anti-N3pGlu Aβ antibody), wherein the anti-N3pGlu Aβ antibody was prepared by a process comprising purifying the anti-N3pGlu antibody from a mammalian host cell, and wherein the total content of host cell proteins (HCPs) in the composition is less than about 100 ppm (as measured by LCMS) and the composition comprises one of, combinations of, or all of the following host cell proteins:

• protein S100-A6, protein S100-A11, phospholipase B-like 2 protein, lysosomal protective protein, ubiquitin-40S ribosomal protein S27a, kallikrein-11, serine protease HTRA1 isoform X1, complement C1r subcomponent, actin, aortic smooth muscle isoform X1, heat shock cognate 71 kDa protein, and peroxiredoxin-1.

(canceled)

194-196. (canceled)

A pharmaceutical composition comprising an antibody that binds to human N3pGlu Ab (anti-N3pGlu Ab antibody), wherein the anti-N3pGlu Ab antibody was prepared by a process comprising purifying the anti-N3pGlu antibody from a mammalian host cell, and wherein the total content of host cell proteins (HCPs) in the composition is less than about 10 ppm (as measured by LCMS) and the composition comprises one of, combinations of, or all of the following host cell proteins:

• polyubiquitin, lysosomal protective protein, glutathione S-transferase Y1, 40S ribosomal protein S28, thioredoxin isoform X1, basement membrane-specific heparan sulfate proteoglycan core protein isoform X1, tubulointerstitial nephritis antigen-like protein, actin-partial cytoplasmic 2 isoform X2, galectin-1, peroxiredoxin-1, and cornifin alpha.

(canceled)

(canceled)