Details for Patent: 6,007,792
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| Title: | Radiolabeled vasoactive intestinal peptides for diagnosis and therapy |
| Abstract: | This invention relates to radiotherapeutic reagents and peptides, radiodiagnostic reagents and peptides, and methods for producing labeled radiodiagnostic and radiotherapeutic agents. Specifically, the invention relates to vasoactive intestinal peptide receptor binding peptides, derivatives and analogues of vasoactive intestinal peptide, and embodiments of such peptides radiolabeled with a radioisotope, as well as methods and kits for making, radiolabeling and using such peptides for radiodiagnostic and radiotherapeutic purposes. The invention specifically relates to vasoactive intestinal peptide receptor binding peptide derivatives and analogues of vasoactive intestinal peptide radiolabeled with technetium-99m and uses thereof as scintigraphic imaging agents. The invention also specifically relates to vasoactive intestinal peptide receptor binding peptide derivatives and analogues of vasoactive intestinal peptide radiolabeled with cytotoxic radioisotopes such as rhenium-186 (.sup.186 Re) and rhenium-188 (.sup.188 Re) for use as radiotherapeutic agents. Methods and kits for making, radiolabeling and using such peptides diagnostically and therapeutically in a mammalian body are also provided. |
| Inventor(s): | Dean; Richard T. (Bedford, NH), Pearson; Daniel A. (Bedford, NH), Lister-James; John (Bedford, NH), Civitello; Edgar R. (Flagstaff, AZ) |
| Assignee: | Diatide, Inc. (Londonderry, NH) |
| Filing Date: | Jan 21, 1998 |
| Application Number: | 08/930,845 |
| Claims: | 1. A complex comprising: a) a radionuclide selected from the group consisting of technetium-99m, rhenium-186, and rhenium-188; and b) a synthetic, receptor-binding vasoactive intestinal peptide covalently linked to a technetium or rhenium chelating moiety; wherein the complex has a vasoactive intestinal peptide receptor binding affinity not less than about one-tenth the affinity of radioiodinated native vasoactive intestinal peptide for said receptor. 2. The complex of claim 1, formed by reacting the synthetic peptide with technetium-99m, rhenium-186, or rhenium-188 in the presence of a reducing agent. 3. The complex of claim 2, wherein the reducing agent is a stannous ion. 4. The complex of claim 1, formed by ligand exchange between the synthetic peptide and a prereduced technetium-99m complex. 5. The complex of claim 1, formed by ligand exchange between the synthetic peptide and a prereduced rhenium-186 complex. 6. The complex of claim 1, formed by ligand exchange between the synthetic peptide and a prereduced rhenium-188 complex. 7. A composition comprising a) a synthetic, receptor-binding vasoactive intestinal peptide covalently linked to a technetium or rhenium chelating moiety; wherein the synthetic peptide when radiolabeled has a vasoactive intestinal peptide receptor binding affinity not less than about one-tenth the affinity of radioiodinated native vasoactive intestinal peptide for said receptor; and b) a stannous ion. 8. A method of labeling a synthetic, receptor-binding vasoactive intestinal peptide covalently linked to a technetium or rhenium chelating moiety comprising the step of reacting the synthetic peptide with technetium-99m, rhenium-186, or rhenium-188 in the presence of a reducing agent, wherein the radiolabeled synthetic peptide has a vasoactive intestinal peptide receptor binding affinity not less than about one-tenth the affinity of radioiodinated native vasoactive intestinal peptide for said receptor. 9. The method of claim 8, wherein the reducing agent is a stannous ion. 10. A method of labeling a synthetic, receptor-binding vasoactive intestinal peptide covalently linked to a technetium or rhenium chelating moiety by ligand exchange, comprising the step of reacting the synthetic peptide with technetium-99m, rhenium-186, or rhenium-188 with a prereduced technetium-99m, rhenium-186, or rhenium-188 complex. 11. A composition comprising a peptide having a formula selected from the group consisting of: 12. A kit comprising a sealed vial containing: a) a predetermined amount of a peptide having a formula selected from the group consisting of: and b) a sufficient amount of a reducing agent to label the peptide with technetium-99m, rhenium-186, or rhenium-188. 13. A method of imaging a tumor within a mammalian body comprising the steps of: a) administering to the body a technetium-99m-labeled peptide having a formula selected from the group consisting of: and b) detecting technetium-99m accumulated at the tumor. 14. A method of treating a tumor within a mammalian body comprising the step of: a) administering to the body a cytotoxic amount of a rhenium-186 or rhenium-188-labeled peptide having a formula selected from the group consisting of: |
