Ethylenedicysteine (EC)-drug conjugates, compositions and methods for tissue specific disease imaging

• US 7,067,111 B1
• Filed: 06/21/2000
• Issued: 06/27/2006
• Est. Priority Date: 10/25/1999
• Status: Expired due to Term

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Yu, Dong-Fang, Yang, David J., Liu, Chun W., Kim, E. Edmund
• Primary Examiner(s): JONES, DAMERON LEVEST
• Application Number:
  US09/599,152
• Time in Patent Office: 2,197 Days
• Field of Search: 424/1.11, 424/1.49, 424/1.65, 424/1.69, 424/1.73, 424 91- 98, 534/7, 534 10- 16, 530/300, 530/311, 530/312, 530/317, 206/223, 206/569, 206/570
• US Class Current: 424/9.1
• CPC Class Codes: A61K 51/04 Organic compounds
• CPC Class Codes: A61K 51/0478 complexes from non-cyclic ligands, e.g. EDTA, MAG3
• CPC Class Codes: A61K 51/0491 Sugars, nucleosides, nucleotides, oligonucleotides, nucleic acids, e.g. DNA, RNA, nucleic acid aptamers
• CPC Class Codes: A61K 51/0497 conjugates with a carrier being an organic compounds
• CPC Class Codes: A61K 51/087 the peptide being an annexin, e.g. annexin V
• CPC Class Codes: A61K 51/088 conjugates with carriers being peptides, polyamino acids or proteins antibodies A61K51/10

Abstract

The invention provides, in a general sense, a new labeling strategy employing ^99mTc chelated with ethylenedicysteine (EC). EC is conjugated with a variety of ligands and chelated to ^99mTc for use as an imaging agent for tissue-specific diseases. The drug conjugates of the invention may also be used as a prognostic tool or as a tool to deliver therapeutics to specific sites within a mammalian body. Kits for use in tissue-specific disease imaging are also provided.

Claims

1. A method of synthesizing a radiolabeled ethylenedicysteine derivative for imaging comprising the steps:

a) obtaining a tissue specific ligand, wherein the tissue specific ligand is an anticancer agent is selected from the group consisting of methotrexate, doxorubicin, tamoxifen, paclitaxel, topotecan, LHRH, mitomycin C, etoposide tomudex, podophyllotoxin, mitoxantrone, camptothecin, colchicine, endostatin, fludarabin, gemcitabine and tomudex;

a) admixing said ligand with ethylenedicysteine (EC) to obtain an EC-tissue specific ligand derivative; and

b) admixing said EC-tissue specific ligand derivative with a radionuclide and a reducing agent to obtain a radionuclide labeled EC-tissue specific ligand derivative, wherein the EC forms an N₂S₂ chelate with the radionuclide.

2. A method of synthesizing a radiolabeled ethylenedicysteine derivative for imaging comprising the steps:

a) obtaining a tissue specific ligand, wherein the tissue specific ligand is a folate receptor targeting ligand selected from the group consisting of folate, methotrexate, and tomudex;

c) admixing said ligand with ethylenedicysteine (EC) to obtain an EC-tissue specific ligand derivative; and

d) admixing said EC-tissue specific ligand derivative with a radionuclide and a reducing agent to obtain a radionuclide labeled EC-tissue specific ligand derivative wherein the EC forms an N₂S₂ chelate with the radionuclide.

21. The method of claim 2, wherein the ligand derivative is ^99mTc-EC-folate.

22. The method of claim 2, wherein the ligand derivative is ^99mTc-EC-methotrexate.

23. The method of claim 2, wherein the ligand derivative is ^99mTc-EC-tomudex.

3. A method of synthesizing a radiolabeled ethylenedicysteine derivative for imaging comprising the steps:

a) obtaining a tissue specific ligand, wherein the tissue specific ligand is a tumor apoptotic cell targeting ligand or a tumor hypoxia targeting ligand selected from the group consisting of annexin V, colchicine, nitroimidazole, mitomycin, and metronidazole;

e) admixing said ligand with ethylenedicysteine (EC) to obtain an EC-tissue specific ligand derivative; and

f) admixing said EC-tissue specific ligand derivative with a radionuclide and a reducing agent to obtain a radionuclide labeled EC-tissue specific ligand derivative, wherein the EC forms an N₂S₂ chelate with the radionuclide.

25. The method of claim 3, wherein the ligand derivative is ^99mTc-EC-annexin V.

26. The method of claim 3, wherein the ligand derivative is ^99mTc-EC-colchicine.

27. The method of claim 3, wherein the ligand derivative is ^99mTc-EC-nitroimidazole.

28. The method of claim 3, wherein the ligand derivative is ^99mTC-EC metronidazole.

4. A method of synthesizing a radiolabeled ethylenedicysteine derivative for imaging comprising the steps:

a) obtaining a tissue specific ligand, wherein the tissue specific ligand is an agent that mimics glucose is selected from the group consisting of neomycin, kanamycin, gentamicin, paromycin, amikacin, tobramycin, netilmicin, ribostamycin, sisomicin, micromicin, lividomycin, dibekacin, isepamicin, astromicin, and an aminoglycoside;

g) admixing said ligand with ethylenedicysteine (EC) to obtain an EC-tissue specific ligand derivative; and

h) admixing said EC-tissue specific ligand derivative with a radionuclide and a reducing agent to obtain a radionuclide labeled EC-tissue specific ligand derivative, wherein the EC forms an N₂S₂ chelate with the radionuclide.

32. The method of claim 4, wherein the ligand derivative is ^99mTc-EC-neomycin.

33. The method of claim 4, wherein the ligand derivative is ^99mTc-EC-kanamycin.

34. The method of claim 4, wherein the ligand derivative is ^99mTc-EC-aminoglycosides.

35. The method of claim 4, wherein the ligand derivative is ^99mTc-EC-gentamycin.

36. The method of claim 4, wherein the ligand derivative is ^99mTc-EC-tobramycin.

5. A method of synthesizing a radiolabeled ethylenedicysteine derivative for imaging comprising the steps:

a) obtaining a tissue specific ligand, wherein the tissue specific ligand is an anticancer agent, a tumor marker, a folate receptor targeting ligand, a tumor apoptotic cell targeting ligand, a tumor hypoxia targeting ligand, glutamate pentapeptide, or an agent that mimics glucose;

b) admixing said ligand with ethylenedicysteine (EC) to obtain an EC-tissue specific ligand derivative; and

c) admixing said EC-tissue specific ligand derivative with a radionuclide and a reducing agent to obtain a radionuclide labeled EC-tissue specific ligand derivative, wherein the EC forms an N₂S₂ chelate with the radionuclide.

14. The method of claim 5, wherein said tissue specific ligand is conjugated to said ethylenedicysteine on both acid arms of the ethylenedicysteine.

15. The method of claim 5, wherein said radionuclide is ^99mTc, ¹⁸⁸Re, ¹⁸⁶Re, ¹⁸³Sm, ¹⁶⁶Ho, ⁹⁰y, ⁸⁹Sr, ⁶⁷Ga, ⁶⁸Ga, ¹¹¹In, ¹⁸³Gd, ⁵⁹Fe, ²²⁵Ac, ²¹²Bi, ₂₁₁At, ⁶⁴Cu or ⁶²Cu.

16. The method of claim 15, wherein said radionuclide is ^99mTc.

17. The method of claim 5, wherein said tissue specific ligand is an anticancer agent.

18. The method of claim 5, wherein said tissue specific ligand is a tumor marker.

19. The method of claim 18, wherein said tumor marker is PSA, ER, PR, CA-125, CA-199, CEA AFP, interferons, BRCA1, HER-2/neu, cytoxan, p53, endostatin, a monoclonal antibody or an antisense tumor marker.

20. The method of claim 5, wherein the tissue specific ligand is a folate receptor targeting ligand.

24. The method of claim 5, wherein the tissue specific ligand is a tumor apoptotic cell targeting ligand or a tumor hypoxia targeting ligand.

29. The method of claim 5, wherein the tissue specific ligand is glutamate pentapeptide.

30. The method of claim 29, wherein the ligand derivative is ^99mTc-EC-glutamate pentapeptide.

31. The method of claim 5, wherein the tissue specific ligand is an agent that mimics glucose.

37. The method of claim 14, further comprising a linker conjugating EC to said tissue specific ligand.

38. The method of claim 37, wherein the linker is a water soluble peptide, glutamic acid, aspartic acid, bromo ethylacetate, ethylene diamine or lysine.

40. The method of claim 5, wherein said reducing agent is a dithionite ion, a stannous ion or a ferrous ion.

6. A method for labeling a tissue specific ligand for imaging, comprising the steps:

a) obtaining a tissue specific ligand, wherein the tissue specific ligand is an anticancer agent, a tumor marker, a folate receptor targeting ligand, a tumor apoptotic cell targeting ligand, a tumor hypoxia targeting ligand, glutamate pentapeptide, or an agent that mimics glucose;

b) admixing the tissue specific ligand with ethylenedicysteine (EC) to obtain an EC-ligand conjugate; and

c) reacting the conjugate with ^99mTc in the presence of a reducing agent to form an N₂S₂ chelate between the ethylenedicysteine (with or without linker) and the ^99mTc.

41. The method of claim 6, wherein the reducing agent is a dithionite ion, a stannous ion or a ferrous ion.

7. A method of imaging a site within a mammalian body comprising the steps of administering an effective diagnostic amount of a composition comprising a ^99mTc labeled ethylenedicysteine-tissue specific ligand conjugate and detecting a radioactive signal from the ^99mTc localized at the site, wherein the tissue specific ligand is an anticancer agent, a tumor marker, a folate receptor targeting ligand, a tumor apoptotic cell targeting ligand, a tumor hypoxia targeting ligand, glutamate pentapeptide, or an agent that mimics glucose.

39. The method of claim 7, wherein the tissue specific ligand is topotecan, paclitaxel, raloxifen, etoposide, doxorubricin, mitomycin C, endostatin, annexin V, LHRH, octreotide, methotrexate or folic acid.

42. The method of claim 7, wherein the site is a tumor.

43. The method of claim 7, wherein the site is an infection.

44. The method of claim 7, wherein the site is breast cancer, ovarian cancer, prostate cancer, endometrium, heart, lung, brain, liver, folate (+) cancer, ER (+) cancer, spleen, pancreas, or intestine.

8. A method of synthesizing a radiolabeled ethylenedicysteine derivative for imaging comprising the steps:

a) obtaining a tissue specific ligand, wherein the tissue specific ligand is glucose or glucosamine;

d) admixing said ligand with ethylenedicysteine (EC) to obtain an EC-tissue specific ligand derivative; and

e) admixing said EC-tissue specific ligand derivative with a radionuclide and a reducing agent to obtain a radionuclide labeled EC-tissue specific ligand derivative, wherein the EC forms an N₂S₂ chelate with the radionuclide.

9. A method of synthesizing a radiolabeled ethylenedicysteine derivative for imaging comprising the steps:

a) obtaining a tissue specific ligand, wherein the tissue specific ligand is deoxyglucose;

f) admixing said ligand with ethylenedicysteine (EC) to obtain an EC-tissue specific ligand derivative; and

g) admixing said EC-tissue specific ligand derivative with a radionuclide and a reducing agent to obtain a radionuclide labeled EC-tissue specific ligand derivative, wherein the EC forms an N₂S₂ chelate with the radionuclide.

10. A method for labeling a tissue specific ligand for imaging, comprising the steps:

a) obtaining a tissue specific ligand, wherein the tissue specific ligand is deoxyglucose;

b) admixing the tissue specific ligand with ethylenedicysteine (EC) to obtain an EC-ligand conjugate; and

c) reacting the conjugate with ^99mTc in the presence of a reducing agent to form an N₂S₂ chelate between the ethylenedicysteine (with or without linker) and the ^99mTc.

11. A method of synthesizing a radiolabeled ethylenedicysteine derivative for imaging comprising the steps:

a) obtaining a tissue specific ligand;

b) admixing said ligand with ethylenedicysteine (EC) to obtain an EC-tissue specific ligand derivative; and

c) admixing said EC-tissue specific ligand derivative with a radionuclide and a reducing agent to obtain a radionuclide labeled EC-tissue specific ligand derivative, wherein the EC forms an N₂S₂ chelate with the radionuclide.

45. The method of claim 11, wherein the tissue specific ligand is an anticancer agent, a tumor marker, a folate receptor targeting ligand, a tumor apoptotic cell targeting ligand, a tumor hypoxia targeting ligand, glutamate pentapeptide, or glucose mimetic.

12. A method for labeling a tissue specific ligand for imaging, comprising the steps:

a) obtaining a tissue specific ligand;

b) admixing the tissue specific ligand with ethylenedicysteine (EC) to obtain an EC-ligand conjugate; and

c) reacting the conjugate with ^99mTc in the presence of a reducing agent to form an N₂S₂ chelate between the ethylenedicysteine (with or without linker) and the ^99mTc.

46. The method of claim 12, wherein the tissue specific ligand is an anticancer agent, a tumor marker, a folate receptor targeting ligand, a tumor apoptotic cell targeting ligand, a tumor hypoxia targeting ligand, glutamate pentapeptide, or glucose mimetic.

13. A method of imaging a site within a mammalian body comprising the steps of administering an effective diagnostic amount of a composition comprising a ^99mTc labeled ethylenedicysteine-tissue specific ligand conjugate and detecting a radioactive signal from the ^99mTc localized at the site.

47. The method of claim 13, wherein the tissue specific ligand is an anticancer agent, a tumor marker, a folate receptor targeting ligand, a tumor apoptotic cell targeting ligand, a tumor hypoxia targeting ligand, glutamate pentapeptide, or glucose mimetic.