Antibody composition-containing medicament

1. A method for treating a disease in a human who is in need of treatment with an anti-CD20 antibody, wherein a CD20 antigen is expressed in a target cell relating to the disease,

wherein the CD-20 antigen is expressed at a level of 1×10 3 to 1×10 5 molecules per cell,

said method comprising administering to said human an anti-CD20 antibody composition,

wherein said anti-CD20 antibody composition comprises anti-CD20 antibody molecules,

wherein said anti-CD20 antibody molecules are produced by a CHO cell,

wherein said anti-CD20 antibody molecules comprise a Fc region comprising complex N-glycoside-linked sugar chains bound to the Fc region though N-acetylglucosamine of the reducing terminal of the sugar chains, and

wherein 100% of said anti-CD20 antibody molecules do not contain sugar chains with a fucose bound to the N-acetylglucosamine,

wherein said CHO cell has no α1,6-fucosyltransferase activity as a result of a genetic engineering method, and

wherein said CHO cell is resistant to a lectin recognizing a sugar chain in which 1-position of fucose is bound to 6-position of N-acetylglucosamine in the reducing end through α-bond in a complex N-glycoside-linked sugar chain.

2. The method according to claim 1 , wherein said CD20 antigen is expressed at a level of 1×10 3 to 5×10 4 molecules per cell in said human.

3. The method according to claim 1 , wherein the lectin is at least one lectin selected from the group consisting of the following (a) to (d):

(a) a Lens culinaris lectin;

(b) a Pisum sativum lectin;

(c) a Vicia faba lectin; and

(d) an Aleuria aurantia lectin.

4. The method according to claim 1 , wherein the anti-CD20 antibody molecules are selected from the group consisting of the following (a) to (d):

(a) a human antibody,

(b) a humanized antibody, and

(c) an antigen binding fragment thereof comprising the Fc region of (a) or (b).

5. The method according to claim 4 , wherein the anti-CD20 antibody molecules are IgG molecules.