Details for Patent: 5,849,261
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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 VIP receptor binding peptides, derivatives and analogues of VIP, 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 VIP receptor binding peptide derivatives and analogues of VIP radiolabeled with technetium-99m and uses thereof as scintigraphic imaging agents. The invention also specifically relates to VIP receptor binding peptide derivatives and analogues of VIP 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. (Bradford, NH) |
| Assignee: | Diatide, Inc. (Londonderry, NH) |
| Filing Date: | Mar 31, 1995 |
| Application Number: | 08/414,424 |
| Claims: | 1. A reagent for preparing a radiopharmaceutical, comprising a synthetic, receptor-binding vasoactive intestinal peptide (VIP) covalently linked to a technetium or rhenium chelating moiety, wherein said chelating moiety is incorporated into the reagent during synthesis of the peptide, and wherein the radiopharmaceutical when labeled with technetium or rhenium has a VIP receptor binding affinity that is not less than about one-tenth the affinity of radioiodinated native VIP for said receptor. 2. A scintigraphic imaging agent comprising the reagent of claim 1 radiolabeled with technetium-99m. 3. A radiotherapeutic agent comprising the reagent of claim 1 radiolabeled with a cytotoxic radioisotope selected from the group consisting of rhenium-186 and rhenium-188. 4. A kit for preparing a radiopharmaceutical preparation, said kit comprising a sealed vial containing a predetermined quantity of the reagent of claim 1 and a sufficient amount of a reducing agent to label the reagent with technetium-99m, rhenium-186 or rhenium-188. 5. The reagent according to claim 1, produced by in vitro chemical synthesis. 6. The reagent according to claim 5 produced by solid phase peptide synthesis. 7. The reagent of claim 1 wherein the chelating moiety has a formula selected from the group consisting of: wherein (pgp).sup.S is H or a thiol protecting group and (aa) is a primary .alpha.- or .beta.-amino acid; wherein A is H, HOOC, H.sub.2 NOC, (amino acid or peptide)13 NHOC, (amino acid or peptide)--OOC or R.sup.4 ; B is H, SH, --NHR.sup.3, --N(R.sup.3)-(amino acid or peptide), or R.sup.4 ; X is H, SH, --NHR.sup.3, --N(R.sup.3)-(amino acid or peptide) or R.sup.4 ; Z is H or R.sup.4 ; R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently H or lower straight or branched chain or cyclic alkyl; n is 0, 1 or 2; (peptide) is a peptide of 2 to about 10 amino acids; and where B is --NHR.sup.3 or --N(R.sup.3)-(amino acid or peptide), X is SH, and n is 1 or 2; where X is --NHR.sup.3 or --N(R.sup.3)-(amino acid or peptide), B is SH, and n is 1 or 2; where B is H or R.sup.4, A is HOOC, H.sub.2 NOC, (amino acid or peptide)--NHOC, (amino acid or peptide)--OOC, X is SH, and n is 0 or 1; where A is H or R.sup.4, then where B is SH, X is --NHR.sup.3 or --N(R.sup.3)-(amino acid or peptide) and where X is SH, B is --NHR.sup.3 or --N(R.sup.3)-(amino acid or peptide) and n is 1 or 2; where X is H or R.sup.4, A is HOOC, H.sub.2 NOC, (amino acid or peptide)-NHOC, (amino acid or peptide)--OOC and B is SH; where Z is methyl, X is methyl, A is HOOC, H.sub.2 NOC, (amino acid or peptide)--NHOC, (amino acid or peptide)--OOC, B is SH and n is 0; and wherein the thiol moiety is in the reduced form and (amino acid) is any primary .alpha.- or .beta.-amino acid not containing a thiol group; ##STR15## wherein each R is independently H, CH.sub.3 or C.sub.2 H.sub.5 ; each (pgp).sup.S is independently a thiol protecting group or H; m, n and p are independently 2 or 3; A=linear or cyclic lower alkyl, aryl, heterocyclyl, combinations or substituted derivatives thereof; ##STR16## wherein each R is independently H, CH.sub.3 or C.sub.2 H.sub.5 ; m, n and p are independently 2 or 3; A=linear or cyclic lower alkyl, aryl, heterocyclyl, combinations or substituted derivatives thereof; V.dbd.H or --CO-peptide; R'.dbd.H or peptide; and wherein when V.dbd.H, R'=peptide and when R'.dbd.H, V=--CO-peptide; wherein each R is independently H, lower alkyl having 1 to 6 carbon atoms, phenyl, or phenyl substituted with lower alkyl or lower alkoxy, and wherein each n is independently 1 or2; a monoamine, diamide, monothiol group having a formula: ##STR17## wherein: n, m and p are each independently 0 or 1, each R'is independently H, lower alkyl, hydroxyalkyl (C.sub.2 -C.sub.4), or alkoxyalkyl (C.sub.2 -C.sub.4); each R is independently H or R", where R"is substituted or unsubstituted lower alkyl or phenyl not comprising a thiol group; one R or R'is L, wherein when an R'is L, --NR'.sub.2 is an amnine; and L is a bivalent linking group linking the radiolabel binding moiety to the peptide; and a monoamine, diamide, monothiol group having a formula: ##STR18## wherein: n, m and p are each independently 0 or 1, each R'is independently H, lower alkyl, hydroxyalkyl (C.sub.2 -C.sub.4), or alkoxyalkyl (C.sub.2 -C.sub.4); each R is independently H or R", where R"is substituted or unsubstituted lower alkyl or phenyl not comprising a thiol group; one R or R'is L, wherein when an R'is L, --NR'.sub.2 is an amine; and L is a bivalent linking group linking the radiolabel binding moiety to the peptide. 8. The reagent of claim 7, wherein the chelating moiety has formula I and (pgp).sup.S has a formula wherein R is a lower alkyl having 1 to 6 carbon atoms, a 2-pyridyl, a 3-pyridyl, a 4-pyridyl, a phenyl, or a phenyl substituted with a lower alkyl, a hydroxy, a lower alkoxy, a carboxy, or a lower alkoxycarbonyl. 9. The reagent of claim 8, wherein the chelating moiety has the formula: ##STR19## . 10. The reagent of claim 7 wherein chelating moiety is selected from the group consisting of: IIa. -(amino acid).sup.1 -(amino acid).sup.2 --{A--CZ(B)--{C(R.sup.1 R.sup.2)}.sub.n --X}, IIb. --{A--CZ(B)--{C(R.sup.1 R.sup.2) }.sub.n --X }-(amino acid).sup.1 -(amino acid).sup.2, IIc. -(a primary .alpha.,.beta.- or .beta.,.gamma.-diamino acid)-(amino acid).sup.1 -{--A--CZ(B)--{C(R.sup.1 R.sup.2) }.sub.n -X}, and IId. --{A--CZ(B)--{C(R.sup.1 R.sup.2)}.sub.n --X}-(amino acid).sup.1 -(a primary .alpha.,.beta.- or .beta.,.gamma.-diamino acid) wherein (amino acid).sup.1 and (amino acid).sup.2 are each independently any naturally-ocurring, modified, substituted or altered .alpha.- or .beta.-amino acid not containing a thio, group; A is H, HOOC, H.sub.2 NOC, (amino acid or peptide)--NHOC, (amino acid or peptide)--OOC or R.sup.4 ; B is H, SH or --NHR.sup.3, --N(R.sup.3)-(amino acid or peptide) or R.sup.4 ; X is SH or --NHR3, --N(R.sup.3)-(amino acid or peptide) or R.sup.4 ; Z is H or R.sup.4 : R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently H or straight or branched chain or cyclic lower alkyl; (peptide) is a peptide of 2 to about 10 amino acids; n is an integer that is either 0, 1 or 2; and where B is --NHR.sup.3 or --N(R.sup.3)-(amino acid or peptide), X is SH and n is 1 or 2; where X is --NHR.sup.3 or --N(R.sup.3)-(amino acid or peptide), B is SH and n is 1 or 2; where B is H or R.sup.4, A is HOOC, H.sub.2 NOC, (amino acid or peptide)--NHOC, (amino acid or peptide)--OOC, X is SH and n is 0 or 1; where A is H or R.sup.4, then where B is SH, X is --NHR.sup.3 or --N(R.sup.3)-(amino acid or peptide) and where X is SH, B is --NHR.sup.3 or --N(R.sup.3)-(amino acid or peptide) and n is 1 or 2; where X is H or R.sup.4, A is HOOC, H.sub.2 NOC, (amino acid or peptide)--NHOC, (amino acid or peptide)--OOC and B is SH; where Z is methyl, X is methyl, A is HOOC, H.sub.2 NOC, (amino acid or peptide)--NHOC, (peptide)--OOC and B is SH and n is 0; and wherein the thiol moiety is in the reduced form. 11. The reagent of claim 7 wherein the monoamine, diamide, monothiol chelating moiety comprising the reagent has the formula: ##STR20## wherein: R.sup.1 and R.sup.2 are each independently H, lower alkyl, hydroxyalkyl (C.sub.2 -C.sub.4) or alkoxyalkyl (C.sub.2 -C.sub.4); R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are independently H, substituted or unsubstituted lower alkyl or phenyl not comprising a thiol group; R.sup.7 and R.sup.8 are each independently H, lower alkyl, lower hydroxyalkyl or lower alkoxyalkyl; L is a bivalent linking moiety; and Z is a peptide. 12. The reagent of claim 7 wherein the monoamine diamide, monothiol chelating moiety has the formula: ##STR21## wherein: R.sup.1 and R.sup.2 are each independently H, lower alkyl, hydroxyalkyl (C.sub.2 -C.sub.4), or alkoxyalkyl (C.sub.2 -C.sub.4); R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are independently H, substituted or unsubstituted lower alkyl or phenyl not comprising a thiol group and one of R.sup.3, R.sup.4, R.sup.5, and R.sup.6 is Z--L--(CR.sub.2).sub.n --, where n is an integer from 1 to 6 and each R is , independently H, lower alkyl, or substituted lower alkyl; R.sup.7 and R.sup.8 are each independently H, lower alkyl, lower hydroxyalkyl or lower alkoxyalkyl; L is a bivalent liking moiety; Z is a peptide; and X is --NH.sub.2,--NR.sup.1 R.sup.2, or --NR.sup.1 --Y, where Y is an amino acid, an amino acid amide, or a peptide of from 2 to about 20 amino acids. 13. The reagent of claim 7 wherein the monoamine, diamide, monothiol chelating moiety has the formula: ##STR22## wherein; R.sup.1 and R.sup.2 are each independently H, lower alkyl, hydroxyalkyl (C.sub.2 -C.sub.4) or alkoxyalkyl (C.sub.2 -C.sub.4); R.sup.3, R.sup.4, R.sup.5, and R.sup.6 independently H, substituted or unsubstituted lower allyl or phenyl not comprising a thiol group; X is --NH.sub.2, --NR.sup.1 R.sup.2,or --NR.sup.1 --Y, where Y is an amino acid, an amino acid amide, or a peptide having from 2 to about 20 amino acids; n is an integer from 1 to 6; L is a bivalent linking moiety; and Z is a peptide. 14. The reagent of claim 7 wherein the monoamine, diamide, monothiol chelating moiety comprising the reagent has the formula: ##STR23## wherein: L is a linker group; and Z is a peptide. 15. The reagent of claim 1 wherein the chelating moiety is selected from the group consisting of: (amino acid).sup.1 -(amino acid).sup.2 -cysteine-, (amino acid).sup.1 -(amino acid).sup.2 -isocysteine-, (amino acid).sup.1 -(amino acid).sup.2 -homocysteine-, (amino acid).sup.1 -(amino acid).sup.2 -penicillamine-, (amino acid).sup.1 -(amino acid).sup.2 -2-mercaptoethylamine-, (amino acid).sup.1 -(amino acid).sup.2 -2-mercaptopropylamine-, (amino acid).sup.1 -(amino acid).sup.2 -2-mercapto-2-methylpropylamine-, (amino acid).sup.1 -(amino acid).sup.2 -3-mercaptopropylamine-, wherein: (amino acid) is a primary .alpha.- or .beta.-amino acid not comprising a thiol, and wherein the chelating moiety is attached to the peptide via a covalent bond with the carboxyl terminus of the chelating moiety or a side chain on one of the amino acid groups comprising the chelating moiety. 16. The reagent of claim 15 wherein (amino acid).sup.1 is either a .alpha.,.omega.- or .beta.,.omega.-diamino acid wherein the .alpha.- or .beta.-amine is a free amine. 17. The reagent of claim 7 wherein the chelating moiety is selected form the group consisting of: -cysteine-(amino acid)-(.alpha.,.beta.- or .beta.,.gamma.-diamino acid); -isocysteine-(amino acid)-(.alpha.,.beta.- or .beta.,.gamma.-diamino acid); -homocysteine-(amino acid)-(.alpha.,.beta.- or .beta.,.gamma.-diamino acid); -penicillamine-(amino acid)-(.alpha.,.beta.- or .beta.,.gamma.-diamino acid); 2-mercaptoacetic acid-(amino acid)-(.alpha.,.beta.- or .beta.,.gamma.-diamino acid); 2- or 3-mercaptopropionic acid-(amino acid)-(.alpha.,.beta.- or .beta.,.gamma.-diamino acid); 2-mercapto-2-methylpropionic acid-(amino acid)-(.alpha.,.beta.- or .beta.,.gamma.-diamino acid); wherein: (amino acid) is a primary .alpha.- or .beta.-amino acid not comprising a thiol; and wherein the chelating moiety is attached to the peptide via a covalent bond with the amino terminus of the chelating moiety or a side chain of one of the amino acid groups comprising the chelating moiety. 18. The reagent of claim 1 wherein the chelating moiety has a formula selected from the group consisting of: Gly-Gly-Cys- Ala-Gly-Cys- -(.epsilon.-Lys)-Gly-Cys- -(.delta.-Orn)-Gly-Cys- -(.gamma.-Dab)-Gly-Cys- -(.beta.-Dap)-Gly-Cys- and -Cys(BAT). 19. A scintigraphic imaging agent comprising the reagent of claim 7 radiolabeled with technetium-99m. 20. A radiotherapeutic agent comprising the reagent of claim 7 and a cytotoxic radioisotope selected from the group consisting of rhenium-186 and rhenium-188. 21. A kit for preparing a radiopharmaceutical preparation, said kit comprising a sealed vial containing a predetermined quantity of the reagent of claim 7 and a sufficient amount of a reducing agent to label the reagent with technetium-99m, rhenium-186 or rhenium-188. 22. A method of radiotherapy for an animal suffering a VIP-related disease, comprising the step of administering an effective therapeutic amount of the agent of claim 20 to the animal. 23. The reagent according to claim 7, produced by in vitro peptide synthesis. 24. The reagent according to claim 23 produced by solid phase peptide synthesis. 25. A method of making the reagent of claim 1, wherein the chelating moiety is incorporated into the reagent at a known position of the peptide. 26. A composition of matter selected from the group consisting of: HSDAVFTDNYTRLRKQMAVKKYLNSILN(.epsilon.-K)GC.amide HSDAVFTDNYTRLRKQMAVKKYLNSILNGGC.amide (SEQ ID No. 2) AGCHSDAVFTDNYTRLRKQMAVKKYLNSILN.amide (SEQ ID No. 3) and HSDAVFTDNYTRLRKQMAVKKYLNSILNC(BAT).amide (SEQ ID No. 4). 27. The composition of matter of claim 24, further comprising technetium-99m. 28. The composition of matter of claim 24, further comprising rhenium-186 or rhenium- 188. 29. A reagent according to claim 1, wherein the chelating moiety is incorporated into the peptide at the carboxyl terminus of the peptide. 30. A reagent according to claim 7, wherein the chelating moiety is incorporated into the peptide at the carboxyl terminus of the peptide. 31. A vasoactive intestinal peptide (VIP) reagent for preparing a radiopharmaceutical, comprising (a) at least two synthetic, VIP receptor-binding peptides; (b) at least two technetium or rhenium chelating moieties, wherein said chelating moieties are incorporated into the reagent during synthesis of the reagent, and (c) a polyvalent linker covalently linked to the peptides and to the chelating moieties, thereby forming a multimeric reagent; wherein (i) said reagent has a molecular weight of less than about 20,000 daltons; and (ii) the radiopharmaceutical when labeled with technetium or rhenium has a VIP receptor binding affinity that is not less than about one-tenth the affinity of radioiodinated native VIP for said receptor. 32. The reagent of claim 1, wherein the peptide has an amino acid sequence -SDAVFTDNYTRLRKQMAVKKYLNSILN.amide (SEQ ID NO:5) and wherein the chelating moiety is incorporated into the reagent at a sidechain of an amino acid in said sequence or at a carboxyl terminus of the peptide. 33. The reagent of claim 7, wherein the peptide has an amino acid sequence -SDAVFTDNYTRLRKQMAVKKYLNSILN.amnide (SEQ ID NO:5) and wherein the chelating moiety is incorporated into the reagent at a sidechain of an amino acid in said sequence or at a carboxyl terminus of the peptide. 34. The reagent of claim 1, wherein the peptide has an amino acid sequence -NYTRLRKQMAVKKYLNSILN.amide (SEQ ID NO:6) and wherein the chelating moiety is incorporated into the reagent at a sidechain of an amino acid in said sequence or at a carboxyl terminus of the peptide. 35. The reagent of claim 7, wherein the peptide has an amino acid sequence -NYTRLRKQMAVKKYLNSILN.amide (SEQ ID NO:6) and wherein the chelating moiety is incorporated into the reagent at a sidechain of an amino acid in said sequence or at a carboxyl terminus of the peptide. 36. The reagent of claim 1, wherein the peptide has an amino acid sequence -KQMAVKKYLNSILN.amide (SEQ ID NO:7) and wherein the chelating moiety is incorporated into the reagent at a sidechain of an amino acid in said sequence or at a carboxyl terminus of the peptide. 37. The reagent of claim 7, wherein the peptide has an amino acid sequence -KQMAVKKYLNSILN.amide (SEQ ID NO:7) and wherein the chelating moiety is incorporated into the reagent at a sidechain of an amino acid in said sequence or at a carboxyl terminus of the peptide. |
