Binding domain-immunoglobulin fusion proteins
View Patent ↗The invention relates to novel binding domain immunoglobulin fusion proteins that feature a binding domain for a cognate structure such as an antigen, a counterreceptor or the like, a hinge region polypeptide having either zero or one cysteine residue, and immunoglobulin CH2 and CH3 domains, and that are capable of ADCC and/or CDC while occurring predominantly as monomeric polypeptides. The fusion proteins can be recombinantly produced at high expression levels. Also provided are related compositions and methods, including immunotherapeutic applications.
1. A binding domain-immunoglobulin fusion protein comprising a binding domain polypeptide capable of binding CD37, a human immunoglobulin hinge region polypeptide, a human CH2 region polypeptide and a human CH3 region polypeptide, wherein the number of cysteines in the hinge region polypeptide is one.
2. The binding domain-immunoglobulin fusion protein of claim 1 , wherein the binding domain polypeptide capable of binding CD37 is derived from the heavy chain variable region and light chain variable region of murine monoclonal antibody G28-1.
3. The binding domain-immunoglobulin fusion protein of claim 2 , wherein the binding domain polypeptide comprises the CDRs of SEQ ID NO: 13.
4. The binding domain-immunoglobulin fusion protein of claim 2 , wherein the binding domain polypeptide comprises the heavy chain variable region or the light chain variable region of SEQ ID NO:13.
5. The binding domain-immunoglobulin fusion protein of claim 2 , wherein the binding domain polypeptide comprises the heavy chain variable region and the light chain variable region of SEQ ID NO:13.
6. The binding domain-immunoglobulin fusion protein of claim 1 , wherein the binding domain polypeptide comprises SEQ ID NO:13.
7. The binding domain-immunoglobulin fusion protein of claim 1 , wherein the binding domain polypeptide comprises a heavy chain variable region and a light chain variable region fused to a linker.
8. The binding domain-immunoglobulin fusion protein of claim 7 , wherein the linker comprises (Gly-Gly-Gly-Gly-Ser) 3 .
9. The binding domain-immunoglobulin fusion protein of claim 1 , wherein the human immunoglobulin hinge region polypeptide is an IgG hinge.
10. The binding domain-immunoglobulin fusion protein of claim 9 , wherein the IgG hinge is an IgG1 wildtype hinge.
11. The binding domain-immunoglobulin fusion protein of claim 1 , wherein the human immunoglobulin hinge region polypeptide is an IgA hinge.
12. The binding domain-immunoglobulin fusion protein of claim 11 , wherein the IgA hinge is a wildtype IgA hinge.
13. The binding domain-immunoglobulin fusion protein of claim 1 , wherein the binding domain-immunoglobulin hinge region polypeptide does not comprise a CH1 domain.
14. The binding domain-immunoglobulin fusion protein of claim 1 , wherein the human CH2 region polypeptide and the human CH3 region polypeptide are human IgG CH2 and CH3 region polypeptides.
15. The binding domain-immunoglobulin fusion protein of claim 1 , wherein the human IgG CH2 and CH3 polypeptides are IgG1 CH2 and CH3 polypeptides.
16. The binding domain-immunoglobulin fusion protein of claim 1 , wherein the polypeptide comprises, from amino to carboxy terminus, the binding domain polypeptide capable of binding CD37 comprising a variable light chain and a variable heavy chain, the human immunoglobulin hinge region polypeptide, the human CH2 region polypeptide, and the human CH3 region polypeptide.
17. The binding domain-immunoglobulin fusion protein of claim 1 , wherein the protein comprises a binding domain polypeptide derived from the heavy chain variable region and light chain variable region of murine monoclonal antibody G28-1, a modified human immunoglobulin hinge region polypeptide, a wildtype human IgG1 CH2 region polypeptide and a wildtype human IgG1 CH3 region polypeptide.
18. The binding domain-immunoglobulin fusion protein of claim 1 , wherein the protein comprises a binding domain polypeptide derived from the heavy chain variable region and light chain variable region of murine monoclonal antibody G28-1, a human IgA immunoglobulin hinge region polypeptide, a wildtype human IgG1 CH2 region polypeptide and a wildtype human IgG1 CH3 region polypeptide.
19. The binding domain-immunoglobulin fusion protein of claim 1 , wherein said protein exhibits ADCC activity.
20. The binding domain-immunoglobulin fusion protein of claim 19 , wherein said protein is capable of killing in an in vitro ADCC assay greater than 50% B lymphoma cells in the presence of human peripheral blood mononuclear cells (PBMCs) at a ratio of 32:1 PBMCs to B lymphoma cells.
21. A pharmaceutical composition comprising the binding-domain immunoglobulin fusion protein of claim 1 and a physiologically acceptable carrier.
22. A method of treating a subject having or suspected of having a malignant condition or B cell disorder comprising administering to the subject a therapeutically effective amount of the pharmaceutical composition of claim 21 , wherein the malignant condition or B cell disorder is associated with CD37 expression.