Methods of manufacturing dimeric antibodies
This disclosure relates to dimeric immunotherapeutics that comprise two IgGs that are crosslinked with a disulfide bond. The two IgGs may be chimeras of two different heavy chains, in which one heavy chain includes a cysteine mutation that forms the disulfide bond, and the other heavy chain lacks the cysteine mutation. The presence of a cysteine mutation in only one of the heavy chains of an IgG avoids two disulfide bonds between the two IgGs, which increases the accessible orientations between the two crosslinked IgGs, and also avoids the formation of trimers and higher-order oligomers.
1. A method to manufacture a dimeric immunotherapeutic, comprising:
providing a first immunotherapeutic and a second immunotherapeutic, wherein (a) the first immunotherapeutic comprises a first IgG with two heavy chains that have a first amino acid sequence; (b) the second immunotherapeutic comprises a second IgG with two heavy chains that have a second amino acid sequence; (c) the first amino acid sequence includes a mutation of a native amino acid to a cysteine; (d) the second amino acid sequence lacks the mutation; (e) the two heavy chains of the first immunotherapeutic are covalently crosslinked with a first one or more disulfide bond(s); and (f) the two heavy chains of the second immunotherapeutic are covalently crosslinked with a second one or more disulfide bond(s);
incubating a solution comprising the first immunotherapeutic and the second immunotherapeutic under reducing conditions to reduce the first one or more disulfide bond(s) and the second one or more disulfide bond(s) such that (a) the two heavy chains of the first immunotherapeutic dissociate to result in half molecules of the first immunotherapeutic; (b) the two heavy chains of the second immunotherapeutic dissociate to result in half molecules of the second immunotherapeutic; and (c) a half molecule of the first immunotherapeutic recombines with a half molecule of the second immunotherapeutic to result in a chimeric immunotherapeutic, which is chimeric at least because it comprises both (i) a heavy chain from the first IgG, which comprises the cysteine, and (ii) a heavy chain from the second IgG, which lacks the cysteine; and
incubating the chimeric immunotherapeutic under oxidizing conditions to form a disulfide bond between (a) the cysteine of the heavy chain from the first IgG of a first molecule of the chimeric immunotherapeutic and (b) the cysteine of the heavy chain from the first IgG of a second molecule of the chimeric immunotherapeutic to result in the dimeric immunotherapeutic, wherein:
the reducing agent is cysteamine;
the first IgG is a human IgG1 or human IgG4;
the native amino acid is S119;
the mutation is S119C;
the first IgG comprises a mutation selected from the group consisting of F405A, F405D, F405E, F405G, F405H, F405I, F405K, F405L, F405M, F405N, F405Q, F405S, F405T, F405V, F405W, F405Y, K409A, K409C, K409D, K409E, K409F, K409G, K409H, K409I, K409N, K409P, K409Q, K409R, K409S, K409T, K409V, K409W, and K409Y;
the second IgG is a human IgG1 or human IgG4;
the second IgG comprises a mutation selected from the group consisting of F405A, F405D, F405E, F405G, F405H, F405I, F405K, F405L, F405M, F405N, F405Q, F405S, F405T, F405V, F405W, F405Y, K409A, K409C, K409D, K409E, K409F, K409G, K409H, K409I, K409N, K409P, K409Q, K409R, K409S, K409T, K409V, K409W, and K409Y; and
amino acid sequences are numbered according to the EU numbering system.
2. The method of claim 1 , wherein:
the first IgG has a first VL CDR1 amino acid sequence, a first VL CDR2 amino acid sequence, a first VL CDR3 amino acid sequence, a first VH CDR1 amino acid sequence, a first VH CDR2 amino acid sequence, and a first VH CDR3 amino acid sequence;
the second IgG has a second VL CDR1 amino acid sequence, a second VL CDR2 amino acid sequence, a second VL CDR3 amino acid sequence, a second VH CDR1 amino acid sequence, a second VH CDR2 amino acid sequence, and a second VH CDR3 amino acid sequence;
the first VL CDR1 amino acid sequence and the second VL CDR1 amino acid sequence are identical;
the first VL CDR2 amino acid sequence and the second VL CDR2 amino acid sequence are identical;
the first VL CDR3 amino acid sequence and the second VL CDR3 amino acid sequence are identical;
the first VH CDR1 amino acid sequence and the second VH CDR1 amino acid sequence are identical;
the first VH CDR2 amino acid sequence and the second VH CDR2 amino acid sequence are identical; and
the first VH CDR3 amino acid sequence and the second VH CDR3 amino acid sequence are identical.
3. The method of claim 1 , wherein:
the first IgG has a first VL CDR1 amino acid sequence, a first VL CDR2 amino acid sequence, a first VL CDR3 amino acid sequence, a first VH CDR1 amino acid sequence, a first VH CDR2 amino acid sequence, and a first VH CDR3 amino acid sequence;
the second IgG has a second VL CDR1 amino acid sequence, a second VL CDR2 amino acid sequence, a second VL CDR3 amino acid sequence, a second VH CDR1 amino acid sequence, a second VH CDR2 amino acid sequence, and a second VH CDR3 amino acid sequence;
the first VL CDR1 amino acid sequence and the second VL CDR1 amino acid sequence are identical to SEQ ID NO: 8;
the first VL CDR2 amino acid sequence and the second VL CDR2 amino acid sequence are identical to SEQ ID NO: 9;
the first VL CDR3 amino acid sequence and the second VL CDR3 amino acid sequence are identical to SEQ ID NO: 10;
the first VH CDR1 amino acid sequence and the second VH CDR1 amino acid sequence are identical to SEQ ID NO: 5;
the first VH CDR2 amino acid sequence and the second VH CDR2 amino acid sequence are identical to SEQ ID NO: 6; and
the first VH CDR3 amino acid sequence and the second VH CDR3 amino acid sequence are identical to SEQ ID NO: 7.
4. The method of claim 1 , wherein:
the first amino acid sequence comprises SEQ ID NO: 3; and
the second amino acid sequence comprises SEQ ID NO: 3.
5. The method of claim 4 , wherein:
the first IgG comprises two light chains that have a first light chain amino acid sequence that comprises SEQ ID NO: 4; and
the second IgG comprises two light chains that have a second light chain amino acid sequence that comprises SEQ ID NO: 4.
6. The method of claim 1 , wherein:
the first IgG comprises two light chains that have a first light chain amino acid sequence;
the second IgG comprises two light chains that have a second light chain amino acid sequence;
the first light chain amino acid sequence and the second light chain amino acid sequence are identical; and
the first IgG and the second IgG bind the same antigen.
7. The method of claim 1 , further comprising purifying the chimeric immunotherapeutic, wherein:
the solution comprises a molar concentration of each of a reducing agent, the first immunotherapeutic, and the second immunotherapeutic;
the solution comprises a combined molar concentration of the first immunotherapeutic and the second immunotherapeutic, which is equal to the sum of the molar concentration of the first immunotherapeutic and the molar concentration of the second immunotherapeutic;
the molar concentration of the reducing agent is at least four times greater than the combined molar concentration;
the purifying separates the chimeric immunotherapeutic from the reducing agent;
incubating the chimeric immunotherapeutic under oxidizing conditions comprises the purifying;
and
incubating the chimeric immunotherapeutic under oxidizing conditions comprises incubating the chimeric immunotherapeutic at a pH of at least 7.0.
8. The method of claim 1 , wherein:
the first IgG is a human IgG4;
the first IgG has a lysine at amino acid position 409 and a phenylalanine at amino acid position 405;
the second IgG is a human IgG4; and
the second IgG has an arginine at amino acid position 409 and a leucine at amino acid position 405.
9. The method of claim 1 , wherein:
the first IgG is a human IgG4;
the first IgG has an arginine at amino acid position 409 and a leucine at amino acid position 405;
the second IgG is a human IgG4; and
the second IgG has a lysine at amino acid position 409 and a phenylalanine at amino acid position 405.
10. The method of claim 1 , further comprising purifying the chimeric immunotherapeutic, wherein:
the solution comprises a reducing agent;
the purifying separates the chimeric immunotherapeutic from the reducing agent; and
incubating the chimeric immunotherapeutic under oxidizing conditions comprises the purifying; and
incubating the chimeric immunotherapeutic under oxidizing conditions comprises incubating the chimeric immunotherapeutic at a pH of at least 7.0.
11. The method of claim 1 , wherein:
the first IgG has a first light chain variable domain amino acid sequence and a first heavy chain variable domain amino acid sequence;
the second IgG has a second light chain variable domain amino acid sequence and a second heavy chain variable domain amino acid sequence;
the first light chain variable domain amino acid sequence and the second light chain variable domain amino acid sequence are identical; and
the first heavy chain variable domain amino acid sequence and the second heavy chain variable domain amino acid sequence are identical.
12. The method of claim 1 , wherein the first IgG and the second IgG bind the same antigen.
13. The method of claim 1 , wherein:
the first IgG is a human IgG1;
the second IgG is a human IgG1; and either
both (i) the first IgG comprises a F405L mutation, and (ii) the second IgG comprises a K409R mutation; or
both (i) the first IgG comprises a K409R mutation, and (ii) the second IgG comprises a F405L mutation.
14. The method of claim 1 , wherein:
the first IgG is a human IgG1.
15. The method of claim 1 , wherein:
the first IgG has a lysine at amino acid position 409 and a phenylalanine at amino acid position 405; and
the second IgG has an arginine at amino acid position 409 and a leucine at amino acid position 405.
16. The method of claim 1 , wherein:
the first IgG has an arginine at amino acid position 409 and a leucine at amino acid position 405; and
the second IgG has a lysine at amino acid position 409 and a phenylalanine at amino acid position 405.