Cytotoxic immunoglobulin
The invention relates to a cytotoxic modular antibody with a molecular weight of up to 60 kD, specifically binding to a cell surface target with a binding affinity of Kd<10 −8 M, a method of producing such antibody and its use as a therapeutic.
1. A method of treating a subject having cancer, comprising administering to the subject having cancer a protein that binds specifically to human Her2, wherein said cancer expresses human HER2, wherein said protein comprises two polypeptides, wherein each polypeptide comprises a human IgG1 heavy chain fragment comprising a CH2 domain and a CH3 domain, wherein the CH3 domain comprises an AB loop comprising the amino acid sequence of SEQ ID NO: 191, a CD loop comprising the amino acid sequence of SEQ ID NO: 241 and an EF loop comprising the amino acid sequence of SEQ ID NO: 370.
2. The method of claim 1 , wherein the CH3 domain comprises the amino acid sequence of the CH3 domain in SEQ ID NO: 1 or SEQ ID NO: 440 exclusive of that of loops AB and EF.
3. The method of claim 1 , wherein the CH2 domain comprises the amino acid sequence of the CH2 domain in SEQ ID NO: 1.
4. The method of claim 2 , wherein the CH2 domain comprises the amino acid sequence of the CH2 domain in SEQ ID NO: 1.
5. The method of claim 1 , wherein the human IgG1 heavy chain fragment comprises a hinge.
6. The method of claim 1 , wherein the human IgG1 heavy chain fragment comprises the amino acid sequence SEQ ID NO: 1 exclusive of that of loops AB and EF.
7. The method of claim 1 , wherein the two polypeptides are connected by a disulfide bond.
8. The method of claim 7 , wherein the two polypeptides are connected by 2 disulfide bonds.
9. The method of claim 1 , wherein said protein binds to human Her2 with a binding affinity of Kd <10 −8 M.
10. The method of claim 1 , wherein said protein is cytotoxic.
11. The method of claim 10 , wherein said protein triggers at least one of antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), complement dependent cytotoxicity (CDC), or apoptotic activity.
12. The method of claim 1 , wherein said protein has a molecular weight of up to 60 kD.
13. The method of claim 1 , wherein said protein has a binding affinity of Kd < 10 −8 M, is cytotoxic, and has a molecular weight of up to 60 kD.
14. A method of treating a subject having cancer, comprising administering to the subject having cancer a protein that specifically binds to human Her2, wherein said cancer expresses human HER2, wherein said protein comprises two polypeptides, wherein each polypeptide comprises a human IgG1 heavy chain fragment comprising a CH2 domain and a CH3 domain, wherein the CH3 domain comprises an AB loop comprising the amino acid sequence of SEQ ID NO: 191, a CD loop comprising the amino acid sequence of SEQ ID NO: 241 and an EF loop comprising the amino acid sequence of SEQ ID NO: 370; and wherein said protein has a molecular weight of up to 60 kD, a binding affinity of Kd <10 −8 M and is cytotoxic.
15. A method of treating a subject having cancer, comprising administering to the subject having cancer a pharmaceutical composition comprising a protein that binds specifically to human Her2 and a pharmaceutically acceptable carrier, wherein said cancer expresses human HER2, wherein said protein comprises two polypeptides, wherein each polypeptide comprises a human IgG1 heavy chain fragment comprising a CH2 domain and a CH3 domain, wherein the CH3 domain comprises an AB loop comprising the amino acid sequence of SEQ ID NO: 191, a CD loop comprising the amino acid sequence of SEQ ID NO: 241 and an EF loop comprising the amino acid sequence of SEQ ID NO: 370.
16. The method of claim 10 , wherein said protein triggers apoptotic activity.
17. The method of claim 14 , wherein the CH3 domain comprises the amino acid sequence of the CH3 domain in SEQ ID NO: 1 or SEQ ID NO: 440, exclusive of that of loops AB and EF.
18. The method of claim 14 , wherein the CH2 domain comprises the amino acid sequence of the CH2 domain in SEQ ID NO: 1.
19. The method of claim 17 , wherein the CH2 domain comprises the amino acid sequence of the CH2 domain in SEQ ID NO: 1.
20. The method of claim 14 , wherein the human IgG1 heavy chain fragment comprises a hinge.
21. The method of claim 14 , wherein the two polypeptides are connected by a disulfide bond.
22. The method of claim 21 , wherein the two polypeptides are connected by 2 disulfide bonds.
23. The method of claim 14 , wherein said protein triggers apoptotic activity.
24. The method of claim 14 , wherein the polypeptides are connected by a disulfide bond, and wherein the CH2 domain comprises the amino acid sequence of the CH2 domain of SEQ ID NO: 1 and the CH3 domain comprises the amino acid sequence of the CH3 domain of SEQ ID NO: 1 or SEQ ID NO: 440 exclusive of that of loops AB and EF.
25. The method of claim 24 , wherein said protein triggers apoptotic activity.
26. The method of claim 24 , wherein the AB loop consists of the amino acid sequence of SEQ ID NO: 191, the CD loop consists of the amino acid sequence of SEQ ID NO: 241 and the EF loop consists of the amino acid sequence of SEQ ID NO: 370.
27. The method of claim 26 , wherein said protein triggers apoptotic activity.
28. The method of claim 14 , wherein the polypeptides are connected by 2 disulfide bonds, and wherein the CH2 domain comprises the amino acid sequence of the CH2 domain of SEQ ID NO: 1 and the CH3 domain comprises the amino acid sequence of the CH3 domain of SEQ ID NO: 1 or SEQ ID NO: 440 exclusive of that of loops AB and EF.
29. The method of claim 28 , wherein said protein triggers apoptotic activity.
30. The method of claim 28 , wherein the AB loop consists of the amino acid sequence of SEQ ID NO: 191, the CD loop consists of the amino acid sequence of SEQ ID NO: 241 and the EF loop consists of the amino acid sequence of SEQ ID NO: 370.
31. The method of claim 30 , wherein said protein triggers apoptotic activity.
32. The method of claim 1 , wherein said cancer overexpresses human HER2.