Details for Patent: 5,620,675
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| Title: | Radioactive peptides |
| Abstract: | This invention relates to therapeutic reagents and peptides, radiodiagnostic reagents and peptides, and methods for producing label radiodiagnostic agents. Specifically, the invention relates to linear peptide derivatives and analogs of somatostatin, 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 linear peptide derivatives and analogues of somatostatin radiolabeled with technetium-99m and uses thereof as scintigraphic imaging agents. The invention so specifically relates to liner peptide derivatives and analogues of somatostatin 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 provide. |
| Inventor(s): | McBride; William (Manchester, NH), Dean; Richard T. (Bedford, NH) |
| Assignee: | Diatech, Inc. (Londonderry, IL) |
| Filing Date: | Jul 21, 1993 |
| Application Number: | 08/095,760 |
| Claims: | 1. A composition of matter that is linear somatostatin receptor-binding peptide reagent having the formula: wherein X.sup.1 and X.sup.2 are each independently hydrophilic moieties wherein X.sup.1 is an amino acid, or a peptide having an amino acid sequence of no more than 10 residues, or a monosaccharide, or an oligosaccharide comprising 10 or fewer saccharide units, or a polyoxyanion, and X.sup.2 is a polyoxyanion, or an amino acid, or a peptide having an amino acid sequence of no more than 10 residues (including peptides wherein the carboxyl group of the carboxyl-terminal amino acid is reduced to an alcohol), or a monosaccharide or an oligosaccharide comprising 10 or fewer saccharide units; A.sup.1, A.sup.2 and C.sup.1 are each independently a lipophilic D- or L-amino acid, or S-alkylated cysteine, penicillamine, homocysteine or homohomocysteine; B.sup.1 is D- or L-Phe, or D- or L-Tyr, or D- or L-Nal, or Ain or substituted derivatives thereof; B.sup.2 is D- or L-Trp or substituted derivatives thereof; B.sup.3 is D- or L-Lys, or Hly, Achxa, Amf, Aec, Apc, Aes, Aps or substituted derivatives thereof; B.sup.4 and C.sup.2 are each independently D- or L-Thr, Ser, Val, Phe, Ile, Abu, Nle, Leu, Nva, Nal or Aib or substituted derivatives thereof; and wherein the somatostatin receptor-binding peptide reagent does not comprise a radiolabel chelating moiety. 2. The composition of matter of claim 1 wherein B.sup.1 is phenylalanine or tyrosine, B.sup.2 is D-tryptophan, B.sup.3 is lysine and B.sup.4 is threonine or valine. 3. The composition of matter of claim 1 further comprising a polyvalent linking moiety that is covalently linked to a multiplicity of the somatostatin receptor-binding peptides to form a multimeric polyvalent somatostatin receptor binding agent, wherein the molecular weight of the multimeric polyvalent somatostatin receptor binding agent is less than about 20,000 daltons. 4. The composition of matter of claim 3 wherein the polyvalent linking moiety is bis-succinimidylmethylether, 4-(2,2-dimethylacetyl)benzoic acid, N-[2-(N',N'-bis(2-succinimidoethyl)aminoethyl)]-N.sup.6, N.sup.9 -bis(2-methyl-2-mercaptopropyl)-6,9-diazanonanamide, tris(succinimidylethyl)amine or a derivative thereof. 5. The composition of matter of claim 1 wherein the somatostatin receptor-binding peptide is chemically synthesized in vitro. 6. The composition of matter of claim 5 wherein the somatostatin receptor-binding peptide is synthesized by solid phase peptide synthesis. 7. A method for alleviating a somatostatin-related disease in an animal comprising administering a therapeutically effective amount of the somatostatin receptor binding peptide of claim 1 to the animal. 8. The method of claim 7 wherein the animal is a human. 9. A composition of matter that is a linear somatostatin receptorbinding peptide reagent having the formula: wherein X.sup.1 is H, lower alkyl or substituted alkyl, aryl or substituted aryl, alkanoyl or substituted alkanoyl, aroyl or substituted aroyl, or a hydrophilic moiety; A.sup.1, A.sup.2 and C.sup.1 are each independently a lipophilic D- or L-amino acid, or S-alkylated cysteine, penicillamine, homocysteine or homohomocysteine; B.sup.1 is D- or L-Phe, or D- or L-Tyr, or D- or L-Nal, or Ain or substituted derivatives thereof; B.sup.2 is D- or L-Trp or substituted derivatives thereof; B.sup.3 is D- or L-Lys, or Hly, Achxa, Amf, Aec, Apc, Aes, Aps or substituted derivatives thereof; B.sup.4 and C.sup.2 are each independently D- or L-Thr, Ser, Val, Phe, Ile, Abu, Nle, Leu, Nva, Nal or Aib or substituted derivatives thereof; X.sup.2 is --COOR.sup.9, --CH.sub.2 OH, CH.sub.2 COOR.sup.9,or --CON(R.sup.9).sub.2, where each R.sup.9 is independently H, lower linear or cyclic alkyl or substituted derivatives thereof or substituted with a hydrophilic moiety; and wherein the somatostatin receptor binding peptide is covalently linked to a radiolabel-binding moiety, wherein the radiolabel-binding moiety is not covalently linked to the moieties B.sup.1, B.sup.2, B.sup.3 or B.sup.4 of the peptide and wherein the radiolabel binding moiety is capable of binding Tc-99m, Re-186 or Re-188. 10. The composition of matter of claim 9 wherein X.sup.1 is a an amino acid, or a peptide having an amino acid sequence of no more than 10 residues, or a monosaccharide, or an oligosaccharide comprising 10 or fewer saccharide units, or a polyoxyanion and X.sup.2 is a polyoxyanion, or an amino acid, or an amino acid, or a peptide having an amino acid sequence of no more than 10 residues, or a monosaccharide, or an oligosaccharide comprising 10 or fewer saccharide units. 11. The composition of matter of claim 9 wherein B.sup.1 is phenylalanine or tyrosine, B.sup.2 is D-otryptophan, B.sup.3 is lysine and B.sup.4 is threonine or valine. 12. The composition of matter of claim 9 wherein the reagent further comprises a polyvalent linking moiety covalently linked to a multiplicity of the somatostatin receptor binding peptides and also covalently linked to a multiplicity of radiolabelbinding moleties to comprise a reagent for preparing a multimeric polyvalent somatostatin receptor binding reagent, wherein the molecular weight of the multimeric polyvalent somatostatin receptor binding reagent is less than about 20,000 daltons. 13. The composition of matter of claim 12 wherein the polyvalent linking moiety is bis-succinimidylmethylether, 4-(2,2-dimethylacetyl)benzoic acid, N-[2-(N',N'-bis(2-succinimidethy)aminethy)]-N.sup.6,N.sup.9 -bis(2-methyl-2-mercaptprpy)-6,9-diazanonanamide, tris(succinimidylethyl)amine or a derivative thereof. 14. A scintigraphic imaging agent comprising the composition of matter of claim 9 radiolabeled with technetium-99m. 15. A radiotherapeutic agent comprising the composition of matter of claim 9 radiolabeled with a cytotoxic radioisotope selected from the group consisting of rhenium-186 and rhenium-188. 16. A complex formed by reacting the composition of matter of claim 9 with technetium-99m in the presence of a reducing agent. 17. The complex of claim 16 ,wherein the reducing agent is selected from the group consisting of a dithionite ion, a stannous ion and a ferrous ion. 18. A complex formed by labeling the composition of matter of claim 9 with technetium-99m by ligand exchange of a prereduced technetium-99m complex. 19. A composition comprising the composition of matter of claim 9 and a stannous ion. 20. A kit for preparing a radiopharmaceutical preparation, said kit comprising a sealed vial containing a predetermined quantity of the composition of matter of claim 9 and a sufficient amount of reducing agent to label the reagent with technetium-99m. 21. A method for labeling a composition of matter according to claim 9 comprising reacting the composition of matter with technetium-99m in the presence of a reducing agent. 22. The method of claim 21, wherein the reducing agent is selected from the group consisting of a dithionite ion, a stannous ion and a ferrous ion. 23. A composition of matter according to claim 9 wherein the somatostatin receptor-binding peptide is chemically synthesized in vitro. 24. A composition of matter according to claim 23 wherein the somatostatin receptor-binding peptide is synthesized by solid phase peptide synthesis. 25. A composition of matter according to claim 23 wherein the radiolabel-binding moiety is covalently linked to the somatostatin receptor-binding peptide during in vitro chemical synthesis. 26. A composition of matter according to claim 25 wherein the radiolabel-binding moiety is covalently linked to the somatostatin receptor-binding peptide during solid phase peptide synthesis. 27. A reagent for preparing a scintigraphic imaging agent for imaging sites within a mammalian body comprising a composition of matter according to claim 9 that is a somatostatin receptor-binding peptide and a radiolabel-binding moiety covalently linked thereto, the radiolabel-binding moiety having the formula: wherein (pgp).sup.s is H or a thiol protecting group and (aa) is an amine acid; or wherein A is H, HOOC, H.sub.2 NOC, (peptide)-NHOC, (peptide)-OOC or R""; B is H, SH, -NHR'", -N(R'")-(peptide), or R""; X is H, SH, -NHR'", -N(R'")-(peptide) or R""; Z is H or R""; R', R", R'" and R"" are independemly H or lower straight or branched chain or cyclic alkyl; n is 0, 1 or 2; and where B is -NHR'" or -N(R'")-(peptide), X is SH, and n is 1 or 2; where X is -NHR'" or -N(R'")-(peptide), B is SH, and n is 1 or 2; where B is H or R"", A is HOOC, H.sub.2 NOC, (peptide)-NHOC, (peptide)-OOC, X is SH, and n is 0 or 1; where A is H or R"", then where B is SH, X is -NHR'" or-N(R'")-(peptide) and where X is SH, B is -NHR'"or-N(R'"-(peptide); where X is H or R"", A is HOOC, H.sub.2 NOC, (peptide)-NHOC, (peptide)-OOC and B is SH; where Z is methyl, X is methyl, A is HOOC, H.sub.2 NOC, (peptide)-NHOC, (peptide)-OOC, B is SH and n is 0; where B is SH and X is SH, n is not 0; or ##STR6## wherein X=H or a protecting group; (amino acid)=any amino acid; or ##STR7## 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; ##STR8## 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=H or-CO-peptide; R'=H or peptide; and wherein when V=H, R'=peptide and when R'=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 or 2. 28. The reagent of claim 27 wherein the cysteine of the radiolabel-binding moiety having formula has a protecting group of the formula wherein R is a lower alkyl having 1 to 6 carbon atoms, 2-,3-,4-pyridyl, phenyl, or phenyl substituted with lower alkyl, hydroxy, lower alkoxy, carboxy, or lower alkoxycarbonyl. 29. The reagent of claim 32 wherein the radiolabel-binding moiety C(pgp).sup.s -(aa)-C(pgp).sup.s has the formula: ##STR9## 30. A scintigraphic imaging agent that is the reagent of claim 27 radiolabeled with technetium-99m. 31. A complex formed by reacting the reagent of claim 27 with technetium-99m in the presence of a reducing agent. 32. The complex of claim 31, wherein the reducing agent is selected from the group consisting of a dithionite ion, a stannous ion and a ferrous ion. 33. A complex formed by labeling the reagent of claim 27 with technetium-99m by ligand exchange of a prereduced technetium-99m complex. 34. A composition comprising the reagent of claim 27 and a stannous ion. 35. A kit for preparing a radiopharmaceutical preparation, said kit comprising a sealed vial containing a predetermined quantity of the reagent of claim 27 and a sufficient amount of reducing agent to label the reagent with technetium-99m. 36. A method for labeling a reagent according to claim 27 comprising reacting the reagent with technetium-99m in the presence of a reducing agent. 37. The method of claim 36, wherein the reducing agent is selected from the group consisting of a dithionite ion, a stannous ion and a ferrous ion. 38. A method for imaging a site within a mammalian body comprising administering an effective diagnostic amount of the reagent of claim 30 and detecting the technetium-99m localized at the site in the mammalian body. 39. The reagent according to claim 27 wherein the somatostatin receptor-binding peptide comprising the reagent is chemically synthesized in vitro. 40. The reagent according to claim 39 wherein the somatostatin receptor-binding peptide is synthesized by solid phase peptide synthesis. 41. The reagent according to claim 39 wherein the radiolabel-binding moiety is covalently linked to the somatostatin receptor-binding peptide during in vitro chemical synthesis. 42. The reagent according to claim 41 wherein the radiolabel-binding moiety is covalently linked to the somatostatin receptor-binding peptide during solid phase peptide synthesis. 43. The reagent of claim 27 wherein the reagent further comprises a polyvalent linking moiety covalently linked to a multiplicity of the somatostatin receptor binding peptides and also covalently linked to a multiplicity of radiolabel-binding moieties to comprise a reagent for preparing a multimeric polyvalent somatostatin receptor binding reagent, wherein the molecular weight of the multimeric polyvalent somatostatin receptor binding reagent is less than about 20,000 daltons. 44. The reagent of claim 43 wherein the polyvalent linking moiety is bis-succinimidylmethylether, 4-(2,2-dimethylacetyl)benzoic acid, N-[2-(N',N'-bis(2-succinimidethyl)aminethyl) ]-N.sup.6,N.sup.9 -bis(2-methyl-2-mercaptopropyl)-6,9-diazannanamide, tris(succinimidylethyl)amine or a derivative thereof. 45. A composition of matter according to claim 9 wherein the radiolabel binding moiety forms a neutral complex with technetium-99m. 46. A composition of matter according to claim 9 radiolabeled with technetium-99m. 47. A composition of matter according to claim 9 radiolabeled with a radioisotope selected from the group consisting of, rhenium-186 and rhenium-188. 48. A composition of matter comprising a somatostatin receptor-binding peptide reagent selected from the group consisting of reagents having the formula: C.sub.Acm GC.sub.Acm GGGF.sub.D.Cpa.YW.sub.D KTFT.amide [DTPA].F.sub.D.Cpa.YW.sub.D KTFT(.epsilon.-K)GC.amide ma. GGGF.sub.D.Cpa.YW.sub.D KTFT.amide Ac.C.sub.Acm GC.sub.Acm F.sub.D.Cpa.YW.sub.D KTFT.amide F.sub.D.Cpa.YW.sub.D KTFTC.sub.Acm GC.sub.Acm.amide [DTPA].D-Nal.Cpa.YW.sub.D KTFT(.epsilon.-K)GC.amide AKCGGGF.sub.D.Cpa.YW.sub.D KTFT.amide [DTPA].D-Nal.Cpa.YW.sub.D KTFT(.epsilon.-K)GC.amide F.sub.D.Cpa.YW.sub.D KTFT.GGGC.sub.Acm GC.sub.Acm.amide [DTPA].Aca.F.sub.D.Cpa.YW.sub.D KTFT(.epsilon.-K)GC.amide [DTPA].(.epsilon.-K)GCF.sub.D.FYW.sub.D KTFT.amide Ac.CGCF.sub.D.Cpa.YW.sub.D KTFT.amide F.sub.D.Cpa.YW.sub.D KTFTCGC.amide [DTPA].(D-Nal.CYW.sub.D KVCT).sub.2 Ac.F.sub.D.FYW.sub.D KTFT(.epsilon.-K)GC.amide Ac.F.sub.D FYW.sub.D KTFTGGG(.epsilon.-K)GC.amide C.sub.Acm GC.sub.Acm GGGF.sub.D.Cpa.YW.sub.D KTFT.amide F.sub.D.Cpa.YW.sub.D KTC.Nal.amide K.[BAT].D-Nal. C.sub.Me YW.sub.D KVC.sub.Me T.amide Ac.F.sub.D FYW.sub.D KTFGGG(.epsilon.-K)KC.amide Pic.GC.sub.Acm GGGF.sub.D.Cpa.YW.sub.D KTFT.amide [DTPA].D-Nal.CYW.sub.D KVCT.amide (2-ketogulonyl)-D-NalFYW.sub.D KVCT.amide F.sub.D.Cpa.YW.sub.D K.Abu.Nal.T(.epsilon.-K)GC.amide [DTPA].K.[BAT].D-Nal.C.sub.Me YW.sub.D KVC.sub.Me T.amide F.sub.D.Cpa.YW.sub.D KTFT(.epsilon.-K)GC.amide [DTPA].F.sub.D FYW.sub.D KTFT(.epsilon.-K)GC.amide AF.sub.D CFW.sub.D KTC.sub.Me T(CH.sub.2 OH) [DTPA].F.sub.D GYW.sub.D KTCT (CH.sub.2 OH) [DTPA].Nal.SYW.sub.D KVTK.[BAT]. amide [DTPA].Nal.SYW.sub.D KVCT.amide. 49. The composition of matter of claim 48 radiolabeled with technetium-99m. 50. The composition of matter of claim 48 radiolabeled with a radioisotope selected from the group consisting of rhenium-186 and rhenium-188. 51. A method for alleviating a somatostatin-related disease in an animal comprising administering a therapeutically effective amount of the composition of matter of claim 1 to the animal. 52. The method of claim 51 wherein the animal is a human. 53. The method of claim 51 wherein the therapeutically effective amount of the composition of matter administered to the animal is from about 0.1 to about 49 mg/kg body weight/day. 54. A method for alleviating a somatostatin-related disease in an animal comprising administering a therapeutically effective amount of the radiotherapeutic agent of claim 15 to the animal. 55. The method of claim 54 wherein the animal is a human. 56. The method of claim 54 wherein the therapeutically effective amount of the radiotherapeutic agent administered to the animal is from about 10 to about 200 mCi. 57. A pharmaceutical composition comprising the radiotherapeutic agent of claim 15 in a pharmaceutically-acceptable carrier. 58. A pharmaceutical composition comprising a composition of matter according to claim 1 that is a somatostatin receptor binding peptide in a pharmaceutically acceptable carrier. 59. A complex formed by reacting the composition of matter of claim 9 with a non-radioactive metal. 60. The complex of claim 59 wherein the non-radioactive metal is rhenium. 61. A complex formed by reacting the composition of matter of claim 12 with a non-radioactive metal. 62. The complex of claim 59 wherein the non-radioactive metal is rhenium. 63. A complex formed by reacting the composition of matter of claim 27 with a non-radioactive metal. 64. The complex of claim 63 wherein the non-radioactive metal is rhenium. 65. A complex formed by reacting the composition of matter of claim 43 with a non-radioactive metal. 66. The complex of claim 38 wherein the non-radioactive metal is rhenium. 67. A complex formed by reacting the composition of matter of claim 48 with a non-radioactive metal. 68. The complex of claim 67 wherein the non-radioactive metal is rhenium. |
