Dual specific immunotoxin for brain tumor therapy

Patent metadata

Field	Value
Publication number	US-9492564-B2
Application number	US-201414270836-A
Country	US
Kind code	B2
Filing date	May 6, 2014
Priority date	Apr 11, 2008
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

We tested the in vitro and in vivo efficacy of a recombinant bispecific immunotoxin that recognizes both EGFRwt and tumor-specific EGFRvIII receptors. A single chain antibody was cloned from a hybridoma and fused to toxin, carrying a C-terminal peptide which increases retention within cells. The binding affinity and specificity of the recombinant bispecific immunotoxin for the EGFRwt and the EGFRvIII proteins was measured. In vitro cytotoxicity was measured. In vivo activity of the recombinant bispecific immunotoxin was evaluated in subcutaneous models and compared to that of an established monospecific immunotoxin. In our preclinical studies, the bispecific recombinant immunotoxin, exhibited significant potential for treating brain tumors.

First claim

The invention claimed is:

1. A method of treating a tumor in a human, comprising:
administering to the human a single chain variable region antibody which binds with a binding affinity that is at least 5×10 8 M −1 as measured by surface plasmon resonance to both (a) EGFR found on normal human cells and (b) EGFR variant III mutant, wherein the single chain variable region antibody is cloned from a hybridoma producing monoclonal antibody D2C7, wherein the single chain variable region antibody is covalently linked to a cytotoxic agent which is a form of Pseudomonas exotoxin A, whereby tumor cells are killed.

2. The method of claim 1 wherein the tumor is a squamous cell head and neck tumor.

3. The method of claim 1 wherein the tumor is a brain tumor.

4. The method of claim 1 wherein the tumor is a breast tumor.

5. The method of claim 1 wherein the tumor is a glioblastoma multiforme.

6. The method of claim 1 wherein the tumor is an astrocytoma.

7. The method of claim 1 wherein the tumor contains an EGFRvIII allele.

8. The method of claim 1 wherein the single chain variable region antibody is administered directly to the central nervous system.

9. The method of claim 1 wherein the single chain variable region antibody is administered directly to the brain.

10. The method of claim 1 wherein the single chain variable region antibody is administered directly to a surgically-created tumor resection cavity.

11. The method of claim 1 wherein the single chain variable region antibody is administered directly to a natural tumor cyst.

12. The method of claim 1 wherein the single chain variable region antibody is administered directly to tumor parenchyma.

13. The method of claim 1 wherein the cytotoxic agent is produced as a fusion protein with the single chain variable region antibody.

14. The method of claim 1 wherein the cytotoxic agent further comprises a KDEL peptide.

15. The method of claim 1 wherein the single chain variable region antibody comprises a VH sequence having SEQ ID NO: 1.

16. The method of claim 1 wherein the single chain variable region antibody comprises a VL sequence having SEQ ID NO: 2.

17. The method of claim 1 wherein the single chain variable region antibody comprises CDR1, CDR2, and CDR3 regions having SEQ ID NOs: 3-8.

Assignees

• Univ Duke
• The Us Secretary Dept Of Health And Human Service
• The Us Secretary Of Health And Human Services Nat Inst Of Health

Inventors

• Bigner Darell
• Kuan Chien-Tsun
• Pastan Ira H
• Peagram Charles

Classifications

• C07K2319/55

  containing a fusion with a toxin, e.g. diphteria toxin · CPC title

• A61P35/00

  Antineoplastic agents · CPC title

• A61K47/6829

  Bacterial toxins, e.g. diphteria toxins or Pseudomonas exotoxin A · CPC title

• C07K2317/565

  Complementarity determining region [CDR] · CPC title

• A61K38/00

  Medicinal preparations containing peptides (peptides containing beta-lactam rings A61K31/00; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, A61K31/00; ergot alkaloids of the cyclic peptide type A61K31/48; containing macromolecular compounds having statistically distributed amino acid units A61K31/74; medicinal preparations containing antigens or antibodies A61K39/00; medicinal preparations characterised by the non-active ingredients, e.g. peptides as drug carriers, A61K47/00) · CPC title