Patent ID: 11891434
Assignee: CHUGAI SEIYAKU KABUSHIKI KAISHA
Field: Measurement (Instruments)
Classification: CPC C  G | IPC C  G

Claim 31:
32. A method of removing a soluble antigen from plasma, the method comprising:
(a) identifying an individual in need of having the antigen removed from the individual's plasma; and
(b) administering to the individual an antibody comprising an antigen-binding domain and a human FcRn-binding domain,
wherein the antibody binds to the antigen through the antigen-binding domain of the antibody and has a KD(Ca2+3 μM)/KD (Ca2+2 mM) value, defined as the ratio of KD for the antigen at a 3 μM calcium ion concentration and KD for the antigen at a 2 mM calcium ion concentration, of 2 to 10,000, when KD is measured using a surface plasmon resonance technique under the following conditions:
37 degrees Celsius, pH 7.4, a running buffer comprising 0.05% polysorbate 20,
10 mmol/L ACES, 150 mmol/L NaCl, and either 3 μM or 2 mM CaCl2), and where
the antibody is immobilized on a CM4 sensor chip, and the antigen serves as analyte,

wherein the antibody binds to the antigen in plasma in vivo and dissociates from the bound antigen under conditions present in an endosome in vivo,
wherein the antibody is a human IgG or a humanized IgG,
wherein the antigen-binding domain comprises a light chain variable domain and a heavy chain variable domain,
wherein the antigen is human IL-6, a soluble form of human IL-6 receptor, a soluble form of human CD4, human IgA, a soluble form of human glypican 3, or human IgE, and
wherein at least four positions selected from Kabat numbering positions 30, 31, 32, 50, and 92 of the light chain variable domain are occupied by amino acids independently selected from serine, threonine, asparagine, glutamine, aspartic acid, glutamic acid, histidine, and tyrosine.