Low-viscosity antigen binding proteins and methods of making them
The present invention concerns a method for preparing antigen binding proteins specific for PCSK9 with reduced viscosity. The method proceeds by replacing residues in high viscosity variable domain subfamilies with residues in correlating low viscosity subfamilies. The method further comprises substituting residues in the Fc domain with residues associated with low viscosity and adding charged residues to the C-terminus of the Fc domain. The present invention further concerns antigen binding proteins produced by this method.
1. A method of reducing the viscosity of an antigen binding protein of the VH1|1-18 germline subfamily, which comprises making viscosity-reducing substitutions 82X 1 , 94X 2 , and 95X 3 in the VH1 amino acid sequence of the antigen binding proteins;
wherein X 1 is selected from R, K and H, X 2 is selected from S, T, N and Q and X 3 is selected from R, K, and H; and wherein the amino acids are numbered according to the Aho numbering system.
2. The method of claim 1 , wherein the viscosity-reducing substitutions comprise 82R, 94S, and 95R.
3. The method of claim 1 , further comprising modifying the VH1 sequence of an antigen binding protein comprising the VH1|1-18 germline subfamily to comprise substitution 59R.
4. The method of claim 1 , which comprises modifying the Fc domain sequence to comprise one or more substitutions selected from 253A, 440K, and 439E.
5. The method of claim 4 , which comprises modifying the Fc domain sequence to comprise substitutions 253A, 440K, and 439E.
6. The method of claim 1 , wherein the antigen binding protein comprises a heavy chain amino acid sequence comprising SEQ ID NO: 136 except for substitutions 82R, 94S, and 95R, and a light chain amino acid sequence comprising SEQ ID NO: 134.
7. The method of claim 1 , wherein the antigen binding protein comprises a heavy chain amino acid sequence comprising SEQ ID NO: 116 except for substitutions 82R, 94S, and 95R, and a light chain amino acid sequence comprising SEQ ID NO: 114.
8. The method of claim 1 , wherein the antigen binding protein comprises a heavy chain amino acid sequence comprising SEQ ID NO: 140 except for substitutions 82R, 94S, and 95R, and a light chain amino acid sequence comprising SEQ ID NO: 138.
9. The method of claim 1 , wherein the antigen binding protein comprises a heavy chain amino acid sequence comprising SEQ ID NO: 148 except for substitutions 82R, 94S, and 95R, and a light chain amino acid sequence comprising SEQ ID NO: 146.
10. The method of claim 1 , wherein the antigen binding protein comprises a heavy chain amino acid sequence comprising SEQ ID NO: 152 except for substitutions 82R, 94S, and 95R, and a light chain amino acid sequence comprising SEQ ID NO: 150.
11. A method of treating a PCSK9-related indication in a patient, which comprises administering to the patient an antibody comprising the heavy and light chain amino acid sequences of SEQ ID NO: 136 and SEQ ID NO: 134, respectively.
12. The method of claim 11 , wherein the PCSK9-related indication is hypercholesterolemia.