CONJUGATE OR ITS SALT COMPRISING A GASTRIN-RELEASING PEPTIDE RECEPTOR ANTAGONIST AND USES THEREOF

1 . A conjugate or a pharmaceutically acceptable salt thereof, the conjugate being of formula: C-L-A,

wherein C is a chelator, L is a linker covalently bound to the chelator and A is a Gastrin-releasing peptide receptor antagonist covalently bound to the linker; and

wherein:

the chelator is of formula:

where the dotted line represents the covalent bond to the linker;

the linker is of formula: -β-Ala-β-Ala-; and

the Gastrin-releasing peptide receptor antagonist has the amino acid sequence:

(SEQ ID NO: 1)

-DPhe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH 2 .

2 . The conjugate or salt of claim 1 , which further comprises a radio-nuclide chelated by the chelator.

3 . The conjugate or salt of claim 2 , in which the radionuclide is a lead radionuclide.

4 . A composition comprising a conjugate or a pharmaceutically acceptable salt thereof, in a pharmaceutically acceptable medium, the conjugate being of formula: C-L-A,

wherein C is a chelator, L is a linker covalently bound to the chelator and A is a Gastrin-releasing peptide receptor antagonist covalently bound to the linker; and

wherein:

the chelator is of formula:

where the dotted line represents the covalent bond to the linker;

the linker is of formula: -β-Ala-β-Ala-; and

the Gastrin-releasing peptide receptor antagonist has the amino acid sequence:

(SEQ ID NO: 1)

-DPhe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH 2 .

5 . A radiopharmaceutical comprising a conjugate or a pharmaceutically acceptable salt thereof, in a pharmaceutically acceptable medium, the conjugate being of formula: C-L-A,

wherein C is a chelator, L is a linker covalently bound to the chelator and A is a Gastrin-releasing peptide receptor antagonist covalently bound to the linker;

wherein:

the chelator is of formula:

where the dotted line represents the covalent bond to the linker;

the linker is of formula: -β-Ala-β-Ala-; and

the Gastrin-releasing peptide receptor antagonist has the amino acid sequence: -DPhe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH 2 (SEQ ID NO: 1); and

wherein the conjugate or salt thereof further comprises a radionuclide chelated by the chelator.

6 . A kit-of-parts, comprising at least:

a first container containing a conjugate or a pharmaceutically acceptable salt thereof, the conjugate being of formula: C-L-A,

wherein C is a chelator, L is a linker covalently bound to the chelator and A is a Gastrin-releasing peptide receptor antagonist covalently bound to the linker;

wherein:

the chelator is of formula:

where the dotted line represents the covalent bond to the linker;

the linker is of formula: -β-Ala-β-Ala-; and

the Gastrin-releasing peptide receptor antagonist has the amino acid sequence: -DPhe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH 2 (SEQ ID NO: 1); and

a second container containing a radionuclide.

7 . The kit-of-parts of claim 6 , in which the radionuclide is a lead radionuclide.

8 . (canceled)

9 . (canceled)

10 . (canceled)

11 . A method for in vivo imaging a cancer or treating a cancer, wherein the cancer overexpresses a Gastrin-releasing peptide receptor in a subject, comprising administering a radiopharmaceutical to the subject, the radiopharmaceutical comprising a conjugate or a pharmaceutically acceptable salt thereof, in a pharmaceutically acceptable medium, the conjugate being of formula: C-L-A,

wherein C is a chelator, L is a linker covalently bound to the chelator and A is a Gastrin-releasing peptide receptor antagonist covalently bound to the linker;

wherein:

the chelator is of formula:

where the dotted line represents the covalent bond to the linker;

the linker is of formula: -β-Ala-β-Ala-; and

the Gastrin-releasing peptide receptor antagonist has the amino acid sequence: -DPhe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH 2 (SEQ ID NO: 1); and

wherein the conjugate or salt thereof further comprises a radionuclide chelated by the chelator.

12 . The method of claim 11 , in which the cancer is a prostate, breast or lung cancer.

13 . The conjugate or salt of claim 3 , in which the lead radionuclide is 203 Pb or 212 Pb.

14 . The radiopharmaceutical of claim 5 , in which the radionuclide is a lead radionuclide.

15 . The radiopharmaceutical of claim 14 , in which the lead radionuclide is 203 Pb or 212 Pb.

16 . The kit-of-parts of claim 7 , in which the lead radionuclide is 203 Pb or 212 Pb.

17 . The method of claim 11 , in which the radionuclide is a lead radionuclide.

18 . The method of claim 17 , in which the lead radionuclide is 203 Pb or 212 Pb.

19 . The method of claim 12 , in which the cancer is a prostate cancer.