Photoimmunoconjugates for use in photodynamic therapy

Patent metadata

Field	Value
Publication number	US-9872904-B2
Application number	US-201214381386-A
Country	US
Kind code	B2
Filing date	Mar 21, 2012
Priority date	Mar 21, 2012
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

A compound comprising
a photosensitizer covalently coupled to a protein selected from the group consisting of antibodies or their derivatives or fragments thereof, synthetic peptides such as scFv, mimotopes which bind CD antigens, cytokine receptors, interleukin receptors, hormone receptors, growth factor receptors, more particularly tyrosine kinase growth factor receptor of the ErbB family, wherein the photosensitizer is coupled to the binding protein via O6-alkylguanine-DNA alkyltransferase (hAGTm), a modified human DNA repair protein.

First claim

The invention claimed is:

1. A compound comprising:
a photosensitizer covalently coupled to
a binding protein selected from the group consisting of an antibody or its antigen-binding fragment thereof; and
wherein the binding protein binds a growth factor receptor,
the photosensitizer is coupled to the binding protein via O6-alkylguanine-DNA alkyltransferase (hAGTm), a modified human DNA repair protein, and
wherein the binding protein comprising the amino acid sequence of SEQ ID NO: 1 or SEQ ID NO: 3.

2. The compound of claim 1 , wherein the photosensitizer is coupled at the active site of the O6-alkylguanine-DNA alkyltransferase.

3. The compound of claim 1 , wherein the photosensitizer is selected from the group consisting of porphyrins, chlorophylls and dyes.

4. The compound of claim 1 , specifically targeting an internalizing and disease-specific cell surface receptor.

5. The compound of claim 1 , wherein the binding protein is an scFv antibody.

6. A compound comprising:
a binding protein comprising the amino acid sequence of SEQ ID NO: 1 or SEQ ID NO: 3,
wherein the binding protein binds a growth factor receptor, and
wherein the binding protein is covalently coupled to a modified human DNA repair protein called O6-alkylguanine-DNA alkyltransferase (hAGTm).

7. The compound of claim 6 , wherein the binding protein is encoded by the polynucleotide sequence of SEQ ID NO: 2 or SEQ ID NO: 4.

8. A compound comprising:
a photosensitizer covalently coupled to
a binding protein comprising a protein encoded by a polynucleotide having the nucleotide sequence of SEQ ID NO: 5;
wherein the binding protein binds a growth factor receptor, and
wherein the photosensitizer is coupled to the binding protein via O6-alkylguanine-DNA alkyltransferase (hAGTm), a modified human DNA repair protein.

9. A method for manufacturing the compound of claim 1 comprising the step of fusing O6-alkylguanine-DNA alkyltransferase (hAGTm) with the binding protein comprising the amino acid sequence of SEQ ID NO: 1 or SEQ ID NO: 3 to form a fusion protein.

10. The method of claim 9 wherein the binding protein encoded by the nucleotide sequence of SEQ ID NO: 2 or SEQ ID NO: 4 is inserted into a SifI and NotI-digested site of eukaryotic expression vector pMS-SNAP providing an N-terminal binding ligand and a C-terminal SNAP-tag sequence.

11. The method of claim 9 wherein the fusion protein is expressed in human embryonic kidney cell line.

12. The method of claim 9 wherein the fusion protein is purified from cell-free supernatant by an affinity chromatography.

13. The compound of claim 1 , wherein the photosensitizer is a porphyrin derivative of the formula

14. A method of manufacturing the compound of claim 13 , comprising reacting the carboxyl groups of the porphyrin derivative with an activated ester or a coupling agent, followed by reacting with O6-benzylguanine, O2-benzylcytosine or a coenzyme A (CoA).

15. The method of claim 14 , wherein O6-benzylguanine, O2-benzylcytosine or CoA is coupled to a linker molecule and/or the activated ester is formed by succinimides, or the coupling agent is a carbodiimide.

16. A medicament comprising the compound of claim 1 and a pharmaceutically acceptable adjuvant for improving or rendering a pharmaceutical effect associated with photoimmunotherapy.

17. A method for treating cancer in a subject by photoimmunotherapy, comprising administering to the subject the compound of claim 1 .

18. The compound of claim 1 , wherein the binding protein is scFv.

19. The compound of claim 1 , wherein the growth factor receptor is a tyrosine kinase growth factor receptor of the ErbB family.

20. The compound of claim 1 , wherein the binding protein is encoded by the polynucleotide sequence of SEQ ID NO: 2 or SEQ ID NO: 4.

21. The compound of claim 6 , wherein the binding protein is scFv.

22. The compound of claim 6 , wherein the growth factor receptor is a tyrosine kinase growth factor receptor of the ErbB family.

Assignees

• Barth Stefan
• Tur Mehmet K
• Hussain Ahmad
• Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E V
• Rheinisch-Westfaelische Technische Hochschule Aachen

Inventors

• Barth Stefan
• Tur Mehmet K
• Hussain Ahmad

Classifications

• C12Y201/01063

  Methylated-DNA-[protein]-cysteine S-methyltransferase (2.1.1.63), i.e. O6-methylguanine-DNA methyltransferase · CPC title

• A61K47/60

  the organic macromolecular compound being a polyoxyalkylene oligomer, polymer or dendrimer, e.g. PEG, PPG, PEO or polyglycerol · CPC title

• C07K16/2878

  against the NGF-receptor/TNF-receptor superfamily, e.g. CD27, CD30, CD40, CD95 · CPC title

• C07K16/2863

  against receptors for growth factors, growth regulators · CPC title

• A61K39/395

  Antibodies (agglutinins A61K38/36 {; as drug carriers A61K47/50}); Immunoglobulins; Immune serum, e.g. antilymphocytic serum · CPC title