DE3991505B4 - Somatostatin peptides, their analogs or derivatives, processes for their preparation and pharmaceutical compositions containing them - Google Patents

Abstract

somatostatin peptides and their analogs or derivatives containing at least one chelating group for a carry detectable element, said chelating group with a terminal amino group of the peptide either directly or indirectly linked and this amino group has no significant binding activity for somatostatin receptors and their complexes with a detectable element, in free form or in salt form.

Description

The The present invention relates to somatostatin peptides, their analogs or derivatives, process for their preparation, pharmaceutical preparations with a content of these polypeptides. Further, their use as a drug, e.g. for the treatment of somatostatin receptor positive Tumors or as in vivo diagnostic Abbidungsmittel described.

In past years has been seen in a number of human tumors, e.g. Pituitary tumors, central nervous system tumors, breast tumors, Gastro-enteropancreatic tumors and their metastases, a potent Occurrence of somatostatin receptors detected. Some of these Tumors are small or slow growing tumors in which one precise Localization by conventional Diagnostic procedure is difficult.

In vitro visualization of somatostatin receptors has been demonstrated by autoradiography of tumor tissues using radioiodinated somatostatin or somatostatin analogs, eg, [ ¹²⁵ I-Tyr ¹¹ ] somatostatin-14 (Taylor, JE et al., Life Science, Vol. 43 (1999); 1988), page 421) or [ ¹²⁵ J-Tyr ³ ] -SMS 201-995, also referred to as [ ¹²⁵ J] 204-090 (Reubi, JC et al., Brain Res., Vol. 406 (1987), p 891; Reubi, JC et al., J. Clin. Endocr. Metab., Vol. 65 (1987), page 1127; Reubi, JC et al., Cancer Res., 47 (1987), 551; Reubi , JC et al., Cancer Res., Vol. 47 (1987), page 5758).

The EP 0 083 129 B1 discloses a method of producing radionuclide labeled proteins, particularly antibodies or antibody fragments, radionuclide labeled proteins, a radiopharmaceutical composition containing radionuclide labeled proteins, and a kit for performing a radiodiagnostic assay comprising a protein provided with chelating groups.

The US patent number U.S. 4,678,667 discloses a copper-chelate conjugate that is stable in human serum. The conjugate is suitable for use in diagnostic and therapeutic applications.

The US patent number US 4,652,519 discloses difunctional chelating agents that are analogs of EDTA, conjugates thereof with a variety of haptens, and conjugates of such conjugates with haptens with metals.

Now were therapeutically valuable, new somatostatin peptides useful for in vivo diagnostic and therapeutic applications can be marked.

According to the invention is a Somatostatin peptide provided, the at least one chelating group for a carries detectable element, this chelating group having a terminal amino group the peptide is linked either directly or indirectly and wherein this amino group has no significant binding affinity for somatostatin receptors, and their complexes with a detectable element, in free form or in salt form according to claim 1.

These Compounds are hereinafter referred to as "INVENTIVE LIGANDS". she have a chelating group that reacts with a detectable element, e.g. a radionuclide, a radiopaque Element or a paramagnetic ion, forming a complex in capable and capable of having a bond with Somatostatin receptors, for example, from tumors or metastases expressed or overexpressed to enter.

The chelating group is over linked a covalent bond to the amino group of the peptide.

The chelating group is to the terminal N-amino group of the somatostatin peptide bound.

According to the invention, the chelating group either be bound directly or indirectly, e.g. above an intermediate group to the amino group of the somatostatin peptide.

A Group of ligands is the one in which the chelating group is bound directly to the amino group of the somatostatin peptide.

A Another group of ligands is the one in which the chelating Group indirectly over a bridge or intermediate group bound to the amino group of the somatostatin peptide is.

Preferably is the chelating group about bound an amide bond to the peptide.

Of the The term "somatostatin peptides" includes naturally occurring ones Somatostatin (tetradecapeptide) and its analogs or derivatives.

Under the term "derivatives or analogues " to understand any straight-chain or cyclic polypeptides which is different from that of course derived tetradecapeptide somatostatin, wherein one or several amino acid units omitted and / or by one or more amino acid residues are replaced and / or where one or more functional groups are replaced by one or more other functional groups and / or one or more groups through one or more other isosteres Groups are replaced. In general, the term includes all modified derivatives of a biologically active peptide containing a qualitatively similar Has the same effect as that of the unmodified somatostatin peptide, so for example, a bond with somatostatin receptors enter and reduce the hormone excretion.

cyclic, brückencyclische and straight-chain somatostatin analogs are known compounds. These Compounds and their preparation are described, for example, in European Patent Publications EP-A-1295; 29,579; 215 171; 203 031; 214,872; 298,732; and 277,419.

worin A C_1-12-Alkyl, C_7-10-Phenylalkyl oder eine Gruppe der Formel RCO- bedeutet, wobei

• i) R Wasserstoff, C_1-11-Alkyl, Phenyl oder C_7-10-Phenylalkyl bedeutet, oder
• ii) RCO-
• a) einen L- oder D-Phenylalaninrest, der gegebenenfalls durch F, Cl, Br, NO₂, NH₂, OH, C_1-3-Alkyl und/oder C_1-3-Alkoxy ringsubstituiert ist;
• b) den Rest einer natürlichen oder synthetischen α-Aminosäure, die von der vorstehenden Definition a) abweicht, oder einer entsprechenden D-Aminosäure oder
• c) einen Dipeptidrest bedeutet, in dem die einzelnen Aminosäurereste gleich oder verschieden sind und aus den vorstehend unter a) und/oder b) definierten Aminosäureresten ausgewählt sind,

wobei die α-Aminogruppe der Aminosäurereste a) und b) und die N-terminale Aminogruppe der Dipeptidreste c) gegebenenfalls mono- oder di-C_1-12-alkyliert oder durch C_1-8-Alkanoyl substituiert sind,
A' Wasserstoff, C_1-12-Alkyl oder C_7-10-Phenylalkyl bedeutet,
Y₁ und Y₂ zusammen eine direkte Bindung bilden oder die Reste Y₁ und Y₂ jeweils unabhängig voneinander Wasserstoff oder einen Rest der Formeln (1) bis (5) bedeuten

worin
R_a Methyl oder Ethyl bedeutet,
R_b Wasserstoff, Methyl oder Ethyl bedeutet,
m eine ganze Zahl von 1 bis 4 ist,
n eine ganze Zahl von 1 bis 5 ist,
R_c (C_1-6)-Alkyl bedeutet,
R_d den an das α-Kohlenstoffatom einer natürlichen oder synthetischen α-Aminosäure (unter Einschluß von Wasserstoff) gebundenen Substituenten bedeutet,
R_e (C_1-5)-Alkyl bedeutet,
R_a, und R_b, unabhängig voneinander Wasserstoff, Methyl oder Ethyl bedeuten,
R₈ und R₉ unabhängig voneinander Wasserstoff, Halogen, (C_1-3)-Alkyl oder (C_1-3)-Alkoxy bedeuten,
p 0 oder 1 ist,
q 0 oder 1 ist und
r 0, 1 oder 2 ist,
B -Phe-, das vorzugsweise durch Halogen, NO₂, NH₂, OH, C_1-3-Alkyl und/oder C_1-3-Alkoxy (unter Einschluß von Pentafluoralanin) ringsubstituiert ist, oder β-Naphthyl-Ala bedeutet,
C (L)-Trp- oder (D)-Trp- bedeutet, die gegebenenfalls α-N-methyliert und gegebenenfalls am Benzolring durch Halogen, NO₂, NH₂, OH, C_1-3-Alkyl und/oder C_1-3-Alkoxy substituiert sind,
D Lys, Lys, bei dem die Seitenkette in ß-Stellung O oder S enthält, γF-Lys oder δF-Lys, gegebenenfalls α-N-methyliert, oder einen 4-AminocyclohexylAla- oder 4-AminocyclohexylGly-Rest bedeutet,
E Thr, Ser, Val, Phe, Ile oder einen Aminoisobuttersäure- oder Aminobuttersäurerest bedeutet,
G einen Rest der Formeln

bedeutet, wobei
R₇ Wasserstoff oder C_1-3-Alkyl bedeutet,
R₁₀ Wasserstoff oder den Rest eines physiologisch verträglichen, physiologisch hydrolysierbaren Esters bedeutet,

R₁₁ Wasserstoff, C_1-3-Alkyl, Phenyl oder C_7-10-Phenylalkyl bedeutet,
R₁₂ Wasserstoff, C_1-3-Alkyl oder eine Gruppe der Formel -CH(R₁₃)-X₁ bedeutet,
R₁₃ CH₂OH, -(CH₂)₂-OH, -(CH₂)₃-OH oder -CH(CH₃)OH bedeutet, oder den an das α-Kohlenstoffatom einer natürlichen oder synthetischen α-Amino säure gebundenen Substituenten (einschließlich Wasserstoff) darstellt, und
X₁ eine Gruppe der Formel -COOR₇, -CH₂OR₁₀ oder

bedeutet,
worin
R₇ und R₁₀ die vorstehend definierte Bedeutung haben,
R₁₄ Wasserstoff oder C_1-3-Alkyl bedeutet und
R₁₅ Wasserstoff, C_1-3-Alkyl, Phenyl oder C_7-10-Phenylalkyl bedeutet und
R₁₆ Wasserstoff oder Hydroxy bedeutet,
mit der Maßgabe, daß
wenn R₁₂ -CH(R₁₃)-X₁ bedeutet, R₁₁ Wasserstoff oder Methyl ist,
wobei die Reste B, D und E die L-Konfiguration aufweisen und die Reste in der 2- und 7-Stellung und beliebige Reste Y₁ 4) und Y₂ 4) jeweils unabhängig voneinander die (L)- oder (D)-Konfiguration aufweisen.Preferred LIGANDS OF THE INVENTION are those derived from the following somatostatin analogs: A. Analogs of Formula I.

wherein AC _1-12 alkyl, C _7-10 phenylalkyl or a group of the formula RCO-, wherein

• i) R is hydrogen, C _1-11 -alkyl, phenyl or C _7-10 -phenylalkyl, or
• ii) RCO
• a) an L- or D-phenylalanine radical which is optionally ring-substituted by F, Cl, Br, NO ₂ , NH ₂ , OH, C _1-3 -alkyl and / or C _1-3 -alkoxy;
• b) the remainder of a natural or synthetic α-amino acid which differs from the above definition a) or a corresponding D-amino acid or
• c) a dipeptide radical in which the individual amino acid residues are identical or different and are selected from the amino acid residues defined above under a) and / or b),

wherein the α-amino group of the amino acid residues a) and b) and the N-terminal amino group of the dipeptide residues c) are optionally mono- or di-C _1-12 -alkylated or substituted by C _1-8 -alkanoyl,
A 'is hydrogen, C _1-12 -alkyl or C _7-10 -phenylalkyl,
Y ₁ and Y ₂ together form a direct bond or the radicals Y ₁ and Y ₂ each independently represent hydrogen or a radical of the formulas (1) to (5)

wherein
R _{a is} methyl or ethyl,
R _{b is} hydrogen, methyl or ethyl,
m is an integer from 1 to 4,
n is an integer from 1 to 5,
R _{c is} (C _1-6 ) -alkyl,
R _{d represents} the substituent attached to the α-carbon atom of a natural or synthetic α-amino acid (including hydrogen),
R _{e is} (C _1-5 ) -alkyl,
R _a , and R _b , independently of one another, denote hydrogen, methyl or ethyl,
R ₈ and R ₉ independently of one another denote hydrogen, halogen, (C _1-3 ) -alkyl or (C _1-3 ) -alkoxy,
p is 0 or 1,
q is 0 or 1 and
r is 0, 1 or 2,
B -Phe-, which is preferably ring-substituted by halogen, NO ₂ , NH ₂ , OH, C _1-3 -alkyl and / or C _1-3 -alkoxy (including pentafluoroalanine), or β-naphthyl-Ala,
C (L) -Trp- or (D) -Trp-, which is optionally α-N-methylated and optionally substituted on the benzene ring by halogen, NO ₂ , NH ₂ , OH, C _1-3 -alkyl and / or C _{1- 3-} alkoxy are substituted,
D Lys, Lys, in which the side chain in the β-position contains O or S, γF-Lys or δF-Lys, optionally α-N-methylated, or denotes a 4-aminocyclohexylAla- or 4-aminocyclohexylGly radical,
E is Thr, Ser, Val, Phe, Ile or an aminoisobutyric or aminobutyric acid radical,
G a remainder of the formulas

means, where
R _{7 is} hydrogen or C _1-3 -alkyl,
R _{10 is} hydrogen or the radical of a physiologically tolerable, physiologically hydrolyzable ester,

R _{11 is} hydrogen, C _1-3 -alkyl, phenyl or C _7-10 -phenylalkyl,
R _{12 is} hydrogen, C _1-3 -alkyl or a group of the formula -CH (R ₁₃ ) -X ₁ ,
R _{13 is} CH ₂ OH, - (CH ₂ ) ₂ -OH, - (CH ₂ ) ₃ -OH or -CH (CH ₃ ) OH, or the substituent attached to the α-carbon atom of a natural or synthetic α-amino acid represents (including hydrogen), and
X _{1 is} a group of the formula -COOR ₇ , -CH ₂ OR ₁₀ or

means
wherein
R ₇ and R _{10 have} the meaning defined above,
R _{14 is} hydrogen or C _1-3 -alkyl and
R _{15 is} hydrogen, C _1-3 alkyl, phenyl or C _7-10 phenylalkyl and
R _{16 is} hydrogen or hydroxy,
with the proviso that
when R _{12 is} -CH (R ₁₃ ) -X ₁ , R _{11 is} hydrogen or methyl,
wherein the radicals B, D and E have the L configuration and the radicals in the 2- and 7-position and any radicals Y ₁ 4) and Y ₂ 4) each independently of the (L) - or (D) configuration exhibit.

The Meanings of A and A 'in of formula I are preferably chosen so that the compound is a terminal Contains -NH group, the can be linked to a chelating agent.

• 1. A bedeutet C_7-10-Phenylalkyl, insbesondere Phenethyl, oder eine Gruppe der Formel RCO. Vorzugsweise bedeutet A eine Gruppe der Formel RCO.
• 1.1. Vorzugsweise bedeutet R C_1-11-Alkyl oder C₇-10-Phenylalkyl, insbesondere C_7-10-Phenylalkyl, ganz besonders Phenethyl oder RCO hat die Bedeutungen a), b) oder c).
• 1.2. Wenn RCO die Bedeutungen a), b) oder c) hat, ist die α-Aminogruppe der Aminosäurereste a) und b) und die N-terminale Aminogruppe der Dipeptidreste c) vorzugsweise nicht-alkyliert oder mono-C_1-12-alkyliert, insbesondere -C_1-8-alkyliert und ganz besonders -methyliert. Insbesondere ist die N-Endgruppe nicht-alkyliert.
• 1.3. Wenn RCO die Bedeutung a) hat, handelt es sich vorzugsweise a') um einen L- oder D-Phenylalanin- oder -Tyrosin-Rest, der gegebenenfalls mono-N-C_1-12-alkyliert ist. Vorzugsweise bedeutet a') einen L- oder D-Phenylalaninrest.
• 1.4. Wenn RCO die Bedeutung b) oder c) hat, ist der definierte Rest vorzugsweise lipophil. Bevorzugte Reste b) sind somit b') α-Aminosäurereste mit einer Kohlenwasserstoffseitenkette, z.B. Alkyl mit 3, vorzugsweise 4 oder mehr C-Atomen, z.B. mit bis zu 7 C-Atomen, Naphthylmethyl oder Heteroaryl, z.B. ein 3-(2- oder 1-Naphthyl)-alanin-, Pyridylmethyl- oder Tryptophanrest, wobei diese Reste die L- oder D-Konfiguration aufweisen. Bevorzugte Reste c) sind Dipeptidreste, bei denen die einzelnen Aminosäurereste gleich oder verschieden sind und unter den vorstehend unter a') und b') definierten Resten ausgewählt sind.

In the compounds of the formula I, the following meanings are preferred either individually or in any combinations or subcombinations:

• 1. A is C _7-10 phenylalkyl, in particular phenethyl, or a group of the formula RCO. Preferably, A is a group of the formula RCO.
• 1.1. Preferably, RC _1-11 -alkyl or C ₇ -10-phenylalkyl, in particular C _7-10 -phenylalkyl, very particularly phenethyl or RCO has the meanings a), b) or c).
• 1.2. When RCO has the meanings a), b) or c), the α-amino group of the amino acid residues a) and b) and the N-terminal amino group of the dipeptide residues c) is preferably non-alkylated or mono-C _1-12 -alkylated, in particular -C _1-8 -alkylated and very particularly -methyliert. In particular, the N-terminal group is non-alkylated.
• 1.3. When RCO has the meaning a), it is preferably a ') is an L- or D-phenylalanine or -tyrosine radical, which is optionally mono-NC _1-12 -alkylated. Preferably, a ') is an L- or D-phenylalanine radical.
• 1.4. When RCO has the meaning b) or c), the defined radical is preferably lipophilic. Preferred radicals b) are thus b ') α-amino acid residues having a hydrocarbon side chain, for example alkyl having 3, preferably 4 or more carbon atoms, for example having up to 7 carbon atoms, naphthylmethyl or heteroaryl, for example a 3- (2- or 1-naphthyl) alanine, pyridylmethyl or tryptophan residue, which residues have the L or D configuration. Preferred radicals c) are dipeptide radicals in which the individual amino acid radicals are identical or different and are selected from the radicals defined above under a ') and b').

• 1.5. Insbesondere weist RCO die Bedeutung a) und ganz besonders die Bedeutung a') auf.
• 2. B bedeutet B', wobei B' Phe oder Tyr ist.
• 3. C bedeutet C', wobei C' (D)Trp ist.
• 4. D bedeutet D', wobei D' Lys, McLys oder Lys(ε-Me), insbesondere Lys, bedeutet.
• 5. E bedeutet E', wobei E' Val oder Thr, insbesondere Thr, bedeutet.
• 6. G bedeutet G', wobei G' eine Gruppe der Formel
  
  und insbesondere eine Gruppe der Formel
  
  bedeutet (wobei in diesem Fall R₁₁ = H oder CH₃). Im letztgenannten Fall weist der Rest -CH(R₁₃)-X₁ vorzugsweise die L-Konfiguration auf.
• 6.1. R₁₁ bedeutet vorzugsweise Wasserstoff.
• 6.2. Als an das α-Kohlenstoffatom einer natürlichen Aminosäure (d.h. der Formel H₂N-CH(R₁₃)-COOH) gebundener Substituent bedeutet R₁₃ vorzugsweise -CH₂OH, -CH(CH₃)-OH, Isobutyl oder Butyl oder R₁₃ bedeutet -(CH₂)₂-OH oder -(CH₂)₃-OH. Insbesondere weist es die Bedeutung -CH₂OH oder -CH(CH₃)OH auf.
• 6.3. X₁ bedeutet vorzugsweise eine Gruppe der Formel
  
  oder -CH₂-OR₁₀, insbesondere der Formel -CH₂-OR₁₀, und R₁₀ bedeutet vorzugsweise Wasserstoff oder hat die nachstehend unter 7 angegebene Bedeutung. Insbesondere bedeutet R₁₀ Wasserstoff.

An example of a radical c) is the 3- (2-naphthyl) alanine residue.

• 1.5. In particular, RCO has the meaning a) and especially the meaning a ').
• 2. B is B ', where B' is Phe or Tyr.
• 3. C is C ', where C' is (D) Trp.
• 4. D is D ', where D' is Lys, McLys or Lys (ε-Me), in particular Lys.
• 5. E is E ', where E' is Val or Thr, in particular Thr.
• 6. G is G ', where G' is a group of the formula
  
  and in particular a group of the formula
  
  means (in which case R ₁₁ = H or CH ₃ ). In the latter case, the radical -CH (R ₁₃ ) -X ₁ preferably has the L-configuration.
• 6.1. R ₁₁ is preferably hydrogen.
• 6.2. As to the α-carbon atom of a natural amino acid (ie the formula H ₂ N-CH (R ₁₃ ) -COOH) ge R ₁₃ preferably denotes -CH ₂ OH, -CH (CH ₃ ) -OH, isobutyl or butyl or R _{13 represents} - (CH ₂ ) ₂ -OH or - (CH ₂ ) ₃ -OH. In particular, it has the meaning -CH ₂ OH or -CH (CH ₃ ) OH.
• 6.3. X ₁ is preferably a group of the formula
  
  or -CH ₂ -OR ₁₀ , in particular of the formula -CH ₂ -OR ₁₀ , and R ₁₀ is preferably hydrogen or has the meaning given below under 7. In particular, R _{10 is} hydrogen.

B. Analoge der Formel II

[vgl. Vale et al., Metabolism, Bd. 27, Supp. 1, (1978) Seite 139]

(vgl. EP-A-200 188).The following individual compounds serve as explanation for compounds of the formula I:

B. Analogues of the formula II

[see. Vale et al., Metabolism, Vol. 27, Supp. 1, (1978) page 139]

(See EP-A-200 188).

Of the Content of all above pamphlets including the specific compounds are made the subject of the present description.

Particularly preferred are LIGANDS derived from

worin
die Reste R₁, R₂ und R₃ jeweils unabhängig voneinander C_1-6-Alkyl, C_6-8-Aryl oder C_7-9-Arylalkyl bedeuten, die jeweils gegebenenfalls durch OH, C_1-4-Alkoxy, COOH oder SO₃H substituiert sind,
n' den Wert 1 oder 2 hat,
i eine ganze Zahl von 2 bis 6 ist,
TT unabhängig voneinander α- oder β-Aminosäuren bedeuten, die miteinander über Amidbindungen verknüpft sind,
Gruppen, die sich von Bisaminothiolderivaten ableiten, z.B. Verbindungen der Formel VI, wie in EP 0 135 160 A1 beschrieben,

worin
die einzelnen Reste R₂₀, R₂₁, R₂₂ und R₂₃ jeweils unabhängig voneinander Wasserstoff oder C_1-4-Alkyl bedeuten,
X₂ eine Gruppe bedeutet, die zur Reaktion mit der N-Aminogruppe des Peptids in der Lage ist, und
m' den Wert 2 oder 3 hat,
Gruppen, die sich von Dithiasemicarbazonderivaten ableiten, z.B. Verbindungen der Formel VII, wie in EP 0 233 619 A1 beschrieben,

worin
X₂ die vorstehend definierte Bedeutung hat,
Gruppen, die sich von Propylenaminoximderivaten ableiten, z.B. Verbindungen der Formel VIII, wie von R.K. Murmann et al. in J. Am. Chem. Soc. 84,1349 (1962) beschrieben,

worin
die einzelnen Reste R₂₀, R₂₅, R₂₆, R₂₇, R₂₈ und R₂₉ unabhängig voneinander Wasserstoff oder C_1-4-Alkyl bedeuten, und
X₂ und m' die vorstehend definierte Bedeutung haben,
Gruppen, die sich von Diamiddimercaptiden ableiten, z.B. Verbindungen der Formel IX

worin
X₃ einen divalenten Rest bedeutet, der gegebenenfalls substituiert ist und eine Gruppe aufweist, die zur Umsetzung mit der N-Aminogruppe des Peptids in der Lage ist, z.B. C_1-4-Alkylen oder Phenylen mit einer Gruppe X₂, und
Y₅ Wasserstoff oder CO₂R₃₀ bedeutet, worin R₃₀ C_1-4-Alkyl bedeutet,
oder Gruppen, die sich von Phorphyrinen ableiten, z.B. N-Benzyl-5,10,15,20-tetrakis-(4-carboxyphenyl)-porphin oder TPP mit einer X₂-Gruppe gemäß der vorstehenden Definition.Suitable chelating groups are physiologically acceptable chelating groups which are used for Formation of a complex with a detectable element are able. Preferably, the chelating group has a substantially hydrophilic character. Examples of chelating groups are iminodicarboxyl groups,
Polyaminopolycarboxyl groups, for example those derived from non-cyclic ligands, such as ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), ethylene glycol-O, O'-bis- (2-aminoethyl) -N, N, N ', N'- tetraacetic acid (EGTA), N, N'-bis- (hydroxybenzyl) ethylenediamine-N, N'-diacetic acid (HBED) and triethylenetetraminehexaacetic acid (TTHA), those derived from substituted EDTA or DPTA, such as p-isothiocyanatobenzyl EDTA or DTPA, those derived from macrocyclic ligands, such as 1,4,7,10-tetraazacyclododecane-N, N ', N'',N''-tetraacetic acid (DOTA) and 1,4,8, 11-tetraazacyclotetradecane-N, N ', N'',N''' - tetraacetic acid (TETA), such as those derived from N-substituted or C-substituted macrocyclic amines, also including cyclams, such as those described in U.S. Pat EP 304 780 A1 and compounds disclosed in WO 89/01476-A, groups of the formula IV or V

wherein
the radicals R ₁ , R ₂ and R _{3 are} each independently C _1-6 alkyl, C _6-8 aryl or C _7-9 arylalkyl, each optionally substituted by OH, C _1-4 alkoxy, COOH or SO ₃ H are substituted,
n 'has the value 1 or 2,
i is an integer from 2 to 6,
TT independently of one another denote α- or β-amino acids which are linked to one another via amide bonds,
Groups derived from Bisaminothiolderivaten, eg compounds of formula VI, as in EP 0 135 160 A1 described,

wherein
the individual radicals R ₂₀ , R ₂₁ , R ₂₂ and R _{23 are} each independently of one another hydrogen or C _1-4 -alkyl,
X _{2 represents} a group capable of reacting with the N-amino group of the peptide, and
m 'has the value 2 or 3,
Groups derived from Dithiasemicarbazonderivaten, eg compounds of formula VII, as in EP 0 233 619 A1 described,

wherein
X _{2 has} the meaning defined above,
Groups derived from Propylenaminoximderivaten, for example compounds of formula VIII, as described by RK Murmann et al. in J. Am. Chem. Soc. 84, 1349 (1962),

wherein
the individual radicals R ₂₀ , R ₂₅ , R ₂₆ , R ₂₇ , R ₂₈ and R ₂₉ independently of one another are hydrogen or C _1-4 -alkyl, and
X ₂ and m 'have the meaning defined above,
Groups derived from Diamiddimercaptiden, eg compounds of formula IX

wherein
X _{3 is} a divalent radical which is optionally substituted and has a group capable of reacting with the N-amino group of the peptide, for example C _1-4 alkylene or phenylene with a group X ₂ , and
Y _{5 is} hydrogen or CO ₂ R ₃₀ , in which R _{30 is} C _1-4 -alkyl,
or groups derived from phorphyrins, eg, N-benzyl-5,10,15,20-tetrakis (4-carboxyphenyl) -porphin or TPP having an X ₂ group as defined above.

aryl is preferably phenyl. Arylalkyl is preferably benzyl.

Examples of X ₂ include radicals of the formula - (X ₄ ) _{n "} -X ₅ , in which X _{4 is} C _1-6 -alkylene or C _1-6 -alkylene, which may be bonded to the carbon atom via an oxygen atom or -NH- is, n '' is 0 or 1 and X _{5 is} -NCS, a carboxy group or a functional derivative thereof, for example an acid halide, anhydride or hydrazide. X ₂ is attached to one of the carbon atoms of - [CH ₂ ] _{m '} - or = CH-CH = to replace a hydrogen atom.

The chelating group can be attached either directly or indirectly to the N-amino group of the somatostatin peptide. If it is indirectly bound, it is preferably linked via a bridging or intermediate group, eg a group of the formula (α1) ZR ₃₅ -CO- (α1) in which
R _{35 is} C _1-11 -alkylene, C _2-11 -alkenylene or -CH (R ') -, where R' is the radical bonded in α-position to the radical of a natural or synthetic α-amino acid, for example hydrogen, C _1-11 alkyl, benzyl, optionally substituted benzyl, naphthylmethyl or pyridylmethyl, and
Z represents a functional group capable of covalent reaction with the chelating agent.
For example, Z may be a radical which may form an ether, ester or amide bond with the chelating group. Z is preferably amino.

The chelating groups may, if they contain carboxy, -SO ₃ H and / or amino groups, be in free form or in salt form.

When chelating groups are those which are derived from polyaminopolycarboxylic acids, e.g. those that are different from EDTA, DTPA, DOTA, TETA or substituted Derive EDTA or DTPA. DTPA-derived chelating groups are particularly preferred.

In the invention LIGANDEN can be the chelating group if it is a polyfunctional Group, either with a single somatostatin peptide molecule or with more than one somatostatin peptide molecule, e.g. with two somatostatin peptide molecules.

The ACCORDING TO THE INVENTION LIGANDEN can for example, in free form or in salt form. Under the salts fall acid addition salts, e.g. with organic acids, polymeric acids or inorganic acids, such as hydrochlorides and acetates, as well as salt forms, with in the chelating group present carboxylic acid or sulfonic acid groups available are, e.g. Alkali metal salts, such as sodium or potassium salts, or substituted or unsubstituted ammonium salts.

The present invention also a method of making the LIGANDS OF THE INVENTION. They can be prepared in analogy to known methods.

• a) indem man mindestens eine Schutzgruppe, die in einem eine chelatbildende Gruppe tragenden Somatostatinpeptid enthalten ist, entfernt, oder
• b) indem man zwei Peptidfragmente miteinander verknüpft, wobei jedes der Peptidfragmente mindestens eine Aminosäure oder einen Aminoalkohol in geschützter oder ungeschützter Form enthält und eines der beiden Fragmente die chelatbildende Gruppe enthält, wobei die Amidbindung in solcher Weise vorliegt, daß die gewünschte Aminosäuresequenz erhalten wird, und indem man gegebenenfalls anschließend die Stufe a) durchführt, oder
• c) indem man eine chelatbildende Gruppe und das gewünschte Somatostatinpeptid in geschützter oder ungeschützter Form auf solche Weise miteinander verknüpft, daß die chelatbildende Gruppe an der gewünschten N-Aminogruppe des Peptids fixiert wird, und indem man anschließend gegebenenfalls die Stufe a) durchführt, oder
• d) indem man eine funktionelle Gruppe eines eine chelatbildende Gruppe tragenden ungeschützten oder geschützten Peptids entfernt oder in eine andere funktionelle Gruppe umwandelt, so daß ein anderes, eine chelatbildende Gruppe tragendes ungeschütztes oder geschütztes Peptid erhalten wird, und indem man im letztgenannten Fall die Stufe a) durchführt, oder
• e) indem man ein mit einer chelatbildenden Gruppe modifiziertes Somatostatinpeptid, bei dem die Mercaptogruppen von Cys-Resten in freier Form vorliegen, oxidiert, so daß ein Analoges gebildet wird, in dem zwei Cys-Reste über eine S-S-Brücke miteinander verbunden sind und indem man den auf diese Weise erhaltenen LIGANDEN in freier Form oder in Salzform gewinnt.

For example, the LIGANDS OF THE INVENTION can be prepared as follows:

• a) by removing at least one protective group contained in a somatostatin peptide carrying a chelating group, or
• b) by coupling two peptide fragments together, each of the peptide fragments containing at least one amino acid or amino alcohol in protected or unprotected form and one of the two fragments containing the chelating group, the amide bond being present in such a way that the desired amino acid sequence is obtained; and, if appropriate, then carrying out the step a), or
• c) by linking a chelating group and the desired somatostatin peptide in protected or unprotected form in such a way that the chelating group is fixed to the desired N-amino group of the peptide, and then optionally carrying out the step a), or
• d) by removing a functional group of an unprotected or protected peptide carrying a chelating group or converting it into another functional group to give another unprotected or protected peptide carrying a chelating group, and in the latter case adding the step a ), or
• e) by oxidizing a somatostatin peptide modified with a chelating group in which the mercapto groups of Cys residues are present in free form, so that an analogue is formed in which two Cys residues are linked to one another via an SS bridge and one wins the LIGANDEN obtained in this way in free form or in salt form.

The above reactions can be carried out in analogy to known methods, as for example in the following examples, in particular the methods a) and c). When the chelating group is bound via an amide bond This can be done in an analogous manner to those used for amide formation Procedure performed become. If desired, can in these reactions, protecting groups suitable for use in Peptides or for the desired chelating groups are suitable for functional groups who do not participate in the implementation. The term "protecting group" also includes a polymer resin having functional groups.

If desired, the chelating moiety is attached to the terminal N-amino group of a peptide or peptide fragment used as the starting material and containing one or more sidechain amino contains groups to bind, these side chain amino groups can be conveniently protected with a protecting group, such as those used in peptide chemistry.

If it desired is the chelating group to a side chain amino group of a Peptides or peptide fragments used as starting material is to bind and the peptide a free terminal N-amino group The latter group is preferably protected with a protecting group protected.

The Peptide fragment carrying the chelating group and used in step b) becomes, lets itself by adding the peptide fragment containing at least one amino acid or an amino alcohol in protected or unprotected Contains form, reacted with the chelating agent. The reaction can be analogous to stage c) become.

worin X eine zur Bildung einer Amidbindung fähige aktivierende Gruppe bedeutet, mit der N-Aminogruppe des Peptids umsetzt. Die Reaktion kann gemäß EP 247 866 A1 durchgeführt werden.The chelating groups of formulas IV or V may be linked to a peptide by reacting a chelating agent of formulas IV 'or V'.

wherein X represents an activatable group capable of forming an amide bond, with the N-amino group of the peptide. The reaction can according to EP 247 866 A1 be performed.

The chelating agents used in step c) may be known or be prepared in analogy to known methods. The used Connection is such that it prevents the introduction of desired chelating group to the somatostatin peptide, e.g. a polyaminopolycarboxylic acid according to the above Information, a salt or anhydride thereof allows.

If in the above method in the amino acids, Peptidfraqmenten or peptides used as starting materials, the chelating group is bound via a bridging or intermediate group to the peptide, for example via a radical of formula (α ₁ ) of the above definition, such amino acids, Peptidfraqmente or Producing peptides by conventionally synthesizing the corresponding amino acids or peptides free of bridging or intermediate groups with a corresponding compound giving a bridge or intermediate, for example an acid or a reactive acid derivative containing the bridging or intermediate group, for example an acid of formula ZR ₃₅ -COOH or a reactive acid derivative thereof such as an active ester, reacting. Examples of active ester groups or carboxyl activating groups are 4-nitrophenyl, pentachlorophenyl, pentafluorophenyl, succinimidyl or 1-hydroxybenzotriazolyl. Another approach is to first react the chelating agent with a bridging or intermediate group-forming compound to introduce the bridging or intermediate group and then reacting with the peptide, peptide fragment or amino acid in a conventional manner.

The ACCORDING TO THE INVENTION LIGANDEN can be used on conventional Way, e.g. by chromatography. Preferably included the invention LIGANDEN less than 5 wt .-% peptides that are free of chelating Groups are.

The ACCORDING TO THE INVENTION LIGANDS in free form or in the form of pharmaceutically acceptable Salts are valuable compounds.

According to a further embodiment, the present invention LIGANDEN with Complex a detectable element.

Accordingly, presents the present invention also relates to the invention LIGANDEN according to the above Definition complexed with a detectable element (hereinafter referred to as INVENTIVE) CHELATE) in free form or in salt form, as well as a method for their preparation and their use for in vivo diagnostic and therapeutic treatments ready.

Under a detectable element is any element, preferably a metal ion, which has a property that in therapeutic or in vivo diagnostic Techniques detectable, e.g. a metal ion that is a detectable Radiation emits or a metal ion, which is to influence NMR relaxation properties is capable.

Suitable detectable metal ions are, for example, ions of heavy elements and rare earth metals, as used in CAT scanning (computer axial tomography), paramagnetic ions, eg Gd ³⁺ , Fe ³⁺ , Mn ²⁺ and Cr ²⁺ , fluorescent metal ions, such as Eu ³⁺ , and radionuclides, eg γ-emitting radionuclides, β-emitting radionuclides, α-emitting radionuclides and positron-emitting radionuclides, eg ⁶⁸ Ga.

Suitable γ-emitting radionuclides include those useful in diagnostic techniques. The γ-emitting radionuclides advantageously have a half-life of from 1 hour to 40 days, preferably from 5 hours to 4 days and in particular from 12 hours to 3 days. Examples of these are gallium, indium, technetium, ytterbium, rhenium and thallium-derived radionuclides such as ⁶⁷ Ga, ¹¹¹ In, ^99m Tc, ¹⁶⁹ Yb and ¹⁸⁶ Re. Preferably, the γ-radionuclide is selected according to the metabolism of the present invention LIGANDEN or somatostatin peptide. In particular, the LIGAND OF THE INVENTION undergoes chelation with a γ radionuclide whose half-life is longer than the half-life of the somatostatin peptide on the tumor.

Further, for illustration purposes suitable radionuclides are positron emitting radionuclides, e.g. the aforementioned.

Suitable β-emitting radionuclides are those suitable for therapeutic applications, eg ⁹⁰ Y, ⁶⁷ Cu, ¹⁸⁶ Re, ¹⁸⁸ Re, ¹⁶⁹ Er, ¹²¹ Sn, ¹²⁷ Te, ¹⁴³ Pr, ¹⁹⁸ Au, ¹⁰⁹ Pd, ¹⁶⁵ Dy, ³² P and ¹⁴² Pr. The β-radionuclide advantageously has a half-life of 2.3 hours to 14.3 days and especially of 2.3 to 100 hours. Preferably, the β-emitting radionuclide is chosen such that its half-life is longer than the half-life of the somatostatin peptide on the tumor.

Suitable α-emitting radionuclides are those used for thereapeutic treatments, eg ²¹¹ At and ²¹² Bi.

The ACCORDING TO THE INVENTION CHELATE can be prepared by reacting the ligand with a compound, which yields a corresponding detectable element, e.g. with a metal salt, and preferably a water-soluble one Salt. The reaction can be carried out analogously to known processes, e.g. as specified by Perrin, Organic Ligand, Chemical Data, Series 22, NY Pergamon Press (1982); Krejcarit and Tucker, Biophys. Biochem. Res. Com., Vol. 77 (1977), page 581 and Wagner and Welch, J. Nucl. Med., Vol. 20 (1979), P. 428.

Preferably the complexation of the ligand is carried out at a pH at that of the invention LIGAND is physiologically stable.

A different possibility is to use the detectable element in the solution as a complex with an intermediary to provide chelating agents, e.g. a chelator Agent that forms a chelate complex, which is the element in physiological pH of LIGANDEN soluble but thermodynamically less stable than the chelate.

One example for such an intermediary chelating agent is 4,5-dihydroxy-1,3-benzenedisulfonic acid (titanium). In such a method, the detectable element exchanges the Ligands off.

The CHELATES OF THE INVENTION may also be prepared by linking a chelating agent complexed to the detectable element and a somatostatin peptide in protected or unprotected form, and optionally deprotecting at least one protecting group present removed. The same reaction can be carried out with a chelating agent complexed with a non-detectable metal ion, in which case in the obtained complexed peptide the metal ion can be replaced by the desired detectable element.

The ACCORDING TO THE INVENTION CHELATE can also be prepared by using the detectable Element complexed chelating agent and a somatostatin peptide fragment, the at least one amino acid in protected or unprotected Contains form, linked together and subsequently the peptide synthesis continues gradually until the final peptide sequence is obtained, and optionally at least one protecting group, the present, removed. Instead of using the detectable element that can chelating agents complexed with a non-detectable metal and this metal can then be complexed in the resulting one Somatostatin peptide can be replaced by a detectable element.

When the chelating group is attached to the somatostatin peptide via a bridging or intermediate group, eg via a moiety of formula (α ₁ ) as defined above, either the somatostatin peptide or peptide fragment or the chelating agent may carry this bridging or intermediate group.

The aforementioned Reactions can be carried out in analogy to known methods. Depending on the existing one chelating group, the marking efficiency can reach 100%, so that one Cleaning is not required. Radionuclides, e.g. Technetium-99m can be used in oxidized form, e.g. Tc-99m pertechnetate, the can be complexed under reducing compounds.

The aforementioned Reactions are expediently carried out under conditions which avoid contamination with trace metals. Preferably are distilled, deionized water, ultrapure reagents, radioactivity of chelation quality and the like. Used to influence of trace metals.

The ACCORDING TO THE INVENTION CHELATE can for example, in free form or in salt form. To the Salts belong Acid addition salts, e.g. with organic acids, polymeric acids or inorganic acids, such as hydrochlorides and acetates, as well as salt forms that are present in the molecule Carboxylic acid groups, which are not involved in chelation, are available, e.g. Alkali metal salts, such as sodium or potassium salts or substituted or unsubstituted Ammonium salts.

The ACCORDING TO THE INVENTION CHELATE and its pharmaceutically acceptable salts possess a pharmaceutical activity and are therefore suitable either as imaging agents, e.g. for visualization of somatostatin receptor-positive tumors and metastases, though They use a paramagnetic, γ-emitting Complexed metal ion or positron emitting radionuclide or as radiopharmaceuticals for the in vivo treatment of somatostatin receptor-positive Tumors and metastases when complexed with an α or β radionuclide, as shown by standard tests.

Especially own the invention CHELATE an affinity for somatostatin receptors, which is expressed or overexpressed by tumors and metastases as shown in standard in vitro binding assays.

A somatostatin receptor positive tumor from the human gastrointestinal tract is removed from a patient, immediately placed on ice and frozen at -80 ° C within a maximum of 30 minutes. For later autoradiography, this frozen material is cut into 10 μm sections in a cryostat (Leitz 1720), mounted on pre-cleaned microscope slides and stored at -20 ° C. for at least 3 days in order to improve the adhesion of the tissue to the slide. Sections are preincubated in Tris-HCl buffer (50 mM, pH 7.4) containing CaCl ₂ (2 mM) and KCl (5 mM) for at least 10 minutes at ambient temperature and then 2 minutes in the same buffer without washed more salt. The sections are then incubated for 2 hours at ambient temperature with a CHELATE according to the invention in Tris-HCl buffer (170 mM, pH 7.4) containing bovine serum albumin (10 g / liter), bacitracin (40 mg / liter) and MgCl ₂ (5 millimolar) for the inhibition of endogenous proteases. Non-specific binding is determined by adding the corresponding unlabelled unmodified somatostatin peptide at a concentration of 1 micromolar. Incubated sections are washed twice for 5 minutes in cold incubation buffer containing 0.25 g / L of BSA. After a short immersion time in distilled water to remove excess salts, the sections are rapidly dried and placed on [ ³ H] LKB films. After an exposure time of about 1 week in X-ray cassettes, it is found that the CHELATES ACCORDING TO THE INVENTION, eg a radionuclide CHELATE, give very good results in the labeling of tumor tissue without labeling the surrounding healthy tissue when added at a concentration of about 10 ^-10 to 10 ^-3 m.

The affinity of the invention CHELATE for Somatostatin receptors can be also show by in vivo tests.

rats with transplantable exocrine, pancreatic somatostatin receptor-positive Tumors are injected with an intravenous injection of a CHELAT of the invention treated. The injection site is the penile vein. Immediately after Upon administration, the animals are placed on the collimator of a gamma camera brought. The radioactivity distribution is recorded at different times. The biological Radioactivity distribution can also killing a standard Number of rats treated in this way and by determination the organ radioactivity be determined.

• 1. Ein Verfahren zum in vivo-Nachweis von Somatostatin-Rezeptor-positiven Tumoren oder Metastasen in einem Subjekt, das folgendes umfaßt: a) Verabreichen eines ERFINDUNGSGEMÄSSEN CHELATS an das Subjekt und b) die Aufzeichnung der Lokalisierung der mit dem CHELAT markierten Rezeptoren. ERFINDUNGSGEMÄSSE CHELATE sind nützlich zur Verwendung bei einem in vivo-Nachweisverfahren, insbesondere CHELATE, die mit einem gamma-emittierenden Radionuklid, einem Positronen emittierenden Radionuklid oder einem paramagnetischen Metallion, wie beispielsweise vorstehend angegeben, komplexiert sind. Die zur Verwendung als Abbildungsmittel im Verfahren (1) verwendeten ERFINDUNGSGEMÄSSEN CHELATE können parenteral, vorzugsweise intravenös, z.B. in Form von injizier baren Lösungen oder Suspensionen, vorzugsweise in einer einzelnen Injektion, verabreicht werden. Die geeignete Dosis hängt selbstverständlich beispielsweise von dem LIGANDEN und dem Typ des verwendeten nachweisbaren Elements, z.B. des Radionuklids, ab. Eine geeignete, zu injizierende Dosis liegt in dem Bereich, die eine Abbildung durch bekannte Photoscanning-Verfahren ermöglicht. Wird ein radioaktiv markiertes ERFINDUNGSGEMÄSSES CHELAT verwendet, kann es vorteilhaft sein, dieses in einer Dosis mit einer Radioaktivität von 0,1 bis 50 mCi, vorzugsweise von 0,1 bis 30 mCi und insbesondere von 0,1 bis 20 mCi zu verabreichen. Ein indizierter Dosisbereich kann 1 bis 200 μg LIGAND betragen, der mit 0,1 bis 50 mCi, vorzugsweise 0,1 bis 30 mCi, z.B. 3 bis 15 mCi, γ-emittierendem Radionuklid, je nach dem verwendeten γ-emittierenden Radionuklid, markiert ist. Beispielsweise ist es bei In bevorzugt, eine Radioaktivität im unteren Bereich zu verwenden, während bei Tc der Einsatz von Radioaktivität im oberen Bereich bevorzugt ist. Der Anreicherung mit. den CHELATEN an den Tumor erzeugenden Stellen können sich die entsprechenden Abbildungstechniken anschließen, z.B. unter Verwendung einer nuklearmedizinischen Abbildungsausrüstung, z.B. einem Scanner, γ-Kamera, rotierenden γ-Kamera, die vorzugsweise jeweils mit einem Computer versehen sind; PET-Scanner (Positron emission tomography); MRI-Ausrüstung oder CAT-Scanning-Ausrüstung. Die ERFINDUNGSGEMÄSSEN CHELATE, z.B. ein Großteil der γ-emittierenden Chelate werden im wesentlichen durch die Nieren ausgeschieden und reichern sich nicht in signifikantem Umfang in der Leber an.
• 2. Verfahren zur in vivo-Behandlung von Somatostatin-Rezeptor-positiven Tumoren und Metastasen bei einem Subjekt, das einer derartigen Behandlung bedarf, wobei dem Sub jekt eine therapeutisch wirksame Menge eines ERFINDUNGSGEMÄSSEN CHELATS verabreicht wird.

After administration of a CHELAT of the invention, eg, radionuclide chelate, eg, a gamma-emitting CHELAT, at a dose of 1 to 5 μg / kg of ligand labeled with 0.1 to 2 mCi of radionuclide, the tumor site is co-located with the organs in which the Excretion essentially takes place, demonstrable. Accordingly, the invention provides, in accordance with a number of specific or alternative embodiments, or is useful for:

• A method for in vivo detection of somatostatin receptor positive tumors or metastases in a subject, comprising: a) administering a CHELAT of the invention to the subject; and b) recording the location of the CHELAT labeled receptors. CHELATES ACCORDING TO THE INVENTION are useful for use in an in vivo detection method, especially CHELATE complexed with a gamma emitting radionuclide, a positron emitting radionuclide, or a paramagnetic metal ion such as noted above. The CHELATES of the invention used for use as imaging agents in process (1) may be administered parenterally, preferably intravenously, eg in the form of injectable solutions or suspensions, preferably in a single injection. Of course, the appropriate dose depends, for example, on the LIGANDEN and the type of detectable element used, eg, the radionuclide. A suitable dose to be injected is in the range that allows imaging by known photoscanning techniques. When a radiolabelled INGREDIENT CHELATE is used, it may be advantageous to administer it at a dose having a radioactivity of from 0.1 to 50 mCi, preferably from 0.1 to 30 mCi, and more preferably from 0.1 to 20 mCi. An indicated dose range may be 1 to 200 μg of LIGAND labeled with 0.1 to 50 mCi, preferably 0.1 to 30 mCi, eg 3 to 15 mCi, γ-emitting radionuclide, depending on the γ-emitting radionuclide used , For example, in In, it is preferable to use lower-range radioactivity, while Tc uses upper-range radioactivity. The enrichment with. the CHELATES at the tumor-producing sites may be followed by the corresponding imaging techniques, eg using nuclear-medical imaging equipment, eg a scanner, γ-camera, rotating γ-camera, preferably each equipped with a computer; PET scanner (positron emission tomography); MRI equipment or CAT scanning equipment. The CHELATES ACCORDING TO THE INVENTION, eg, a majority of the γ-emitting chelates, are essentially excreted by the kidneys and do not accumulate to any significant extent in the liver.
• 2. A method for in vivo treatment of somatostatin receptor-positive tumors and metastases in a subject in need of such treatment, wherein the subject is administered a therapeutically effective amount of a CHELAT of the invention.

at the chelates of the invention it is for use in an in vivo treatment procedure CHELRTE treated with an α- or β-radionuclide according to the above Definition are complexed.

The during execution Of course, for example, doses used in the therapeutic procedure vary depending on the particular condition to be treated, e.g. the volume of the tumor, the CHELAT used, e.g. the half-life of CHELATE in the tumor, and the desired Therapy. In general, the dose will be based on the radioactivity distribution to the individual organs and according to the observed Target acquisition calculated. For example, the CHELAT with a daily Dose range with a radioactivity of 0.1 to 3 mCi / kg body weight, e.g. 1 to 3 mCi and preferably 1 to 1.5 mCi / kg of body weight be administered. An indicated daily dose range is 1 to 200 μg LIGAND, labeled with 0.1 to 3 mCi / kg of body weight, e.g. 0.1 to 1.5 mCi / kg body weight at α- or β-emitting Radionuclide, expediently administered in divided doses up to 4 times daily.

The α- or β-emitting ACCORDING TO THE INVENTION CHELATE can on any conventional Administered administration routes, in particular parenteral, e.g. in the form of injectable solutions or suspensions. You can also be advantageously administered by infusion, e.g. by an infusion of 30 to 60 minutes. Depending on the tumor site Become as close as you can administered to the tumor, e.g. by means of a catheter. The chosen mode of administration can from the dissociation rate of the used CHELATS and the rate of excretion.

The ACCORDING TO THE INVENTION CHELATE can be administered in free form or in pharmaceutically acceptable form. Such salts can be prepared in a conventional manner and have an activity in the same order of magnitude like the free connections on.

The ACCORDING TO THE INVENTION CHELATE in a method described herein may preferably are prepared shortly before administration to a subject, i. the radioactive label with the desired detectable metal ion, in particular with the desired α-, β- or γ-radionuclide, can be done just before administration.

The ACCORDING TO THE INVENTION CHELATE are suitable for imaging or treating tumors, such as Pituitary tumors, gastroenteropancreatic tumors, central nervous system tumors, Breast tumors, prostate tumors, ovarian tumors or colon tumors, small cell lung cancer, paragangliomas, neuroblastomas, pheochromocytomas, medullary Thyroid carcinomas, myelomas and the like, as well as metastases thereof.

Further can the γ-emitting ACCORDING TO THE INVENTION CHELATE also as an imaging agent for evaluation of renal function be used.

It become groups of five mice used. Every mouse gets through a tail vein with an intravenous injection of 0.1 ml a content of 1 mCi of a CHELAT of the invention. Then be the mice brought to the collection of excreted urine in metabolic cages. Ten or 120 minutes after the injection, the urethra is tied off and the mice anesthetized with chloroform. The Illustration of the uro poetic system is using the usual Imaging technique performed. In this test, the γ-emitting enhance ACCORDING TO THE INVENTION CHELATE the mapping of renal excretion upon administration in a dose of 0.1 to 30 mCi.

Accordingly, the Invention also useful in a method for in vivo evaluation of renal function of a Subject receiving the administration of an effective amount of a γ-emitting CHELATS to the subject and the record of renal function.

• i. eine pharmazeutische Zusammensetzung mit einem Gehalt an einem ERFINDUNGSGEMÄSSEN LIGANDEN in freier Form oder in Form eines pharmazeutisch verträglichen Salzes zusammen mit einem oder mehreren pharmazeutisch verträglichen Trägerstoffen oder Verdünnungsmitteln hierfür;
• ii. eine pharmazeutische Zusammensetzung mit einem Gehalt an einem CHELAT gemäß der Erfindung in freier Form oder in Form eines pharmazeutisch verträglichen Salzes zusammen mit einem oder mehreren pharmazeutisch verträglichen Trägerstoffen oder Verdünnungsmitteln hierfür.

According to another aspect of the invention, the following is provided:

• i. a pharmaceutical composition comprising a LIGANDEN of the invention in free form or in the form of a pharmaceutically acceptable salt together with one or more pharmaceutically acceptable carriers or diluents therefor;
• ii. a pharmaceutical composition containing CHELATE according to the invention in free form or in the form of a pharmaceutically acceptable salt together with one or more pharmaceutically acceptable carriers or diluents therefor.

such Compositions can be prepared in a conventional manner.

A Composition according to the invention can also be packed in separate packaging along with instructions for Mixing the LIGANDEN with the metal ion and for administration of the obtained CHELAT. It can also be in shape a double pack, i. a single pack, the separate Unit doses of LIGANDEN and detectable metal ion contains together with instructions for their mixing and administration of the CHELAT. A diluent or carrier may be in the unit dosage forms.

Boc:

tert.-Butoxycarbonyl

TFA:

Trifluoressigsäure

DTPA:

Diethylentriamin-pentaessigsäure

In the following examples all temperatures are given in ° C and the [α] ²⁰ _D values are uncorrected. The following abbreviations are used:

Boc:

tert-butoxycarbonyl

TFA:

trifluoroacetic

DTPA:

Diethylenetriamine pentaacetic acid

example 1

und 500 mg entsprechend dimerem

1.1 g of DPhe-Cys-Phe-DTrp-Lys (ε-Boc) -Thr-Cys-Thr-ol in the form of the free base (1 millimolar) are dissolved in 5 liters of dioxane / H ₂ O 1/1 (vol. / Vol.) And treated with 5 g NaHCO ₃ . 520 mg DTPA dianhydride is added slowly with stirring. The reaction mixture is stirred for a further 30 minutes and freeze-dried. The residue is dissolved in 250 ml of water and the pH is adjusted to 2.5 with concentrated HCl. The precipitated product is filtered off, washed and dried over phosphorus pentoxide. After chromatography on a silica gel column, the following products are isolated: 230 mg

and 500 mg corresponding to dimerem

vermischt. Nach 5 Minuten bei Raumtemperatur wird das Gemisch mit Diisopropylether gefällt, abfiltriert und getrocknet. Der Rückstand wird über Duolite entsalzt und lyophilisiert. Man erhält 150 mg der Titelverbindung: [α]²⁰ _D = –26,6° (c = 1,95, % AcOH).3 ml of TFA are mixed with 200 mg

mixed. After 5 minutes at room temperature, the mixture is precipitated with diisopropyl ether, filtered off and dried. The residue is desalted over Duolite and lyophilized. 150 mg of the title compound are obtained: [α] ²⁰ _D = -26.6 ° (c = 1.95,% AcOH).

• a)
  
  2,25 g Di-tert.-butylpyrocarbonat, gelöst in 30 ml DMF, werden langsam bei Raumtemperatur zu einer Lösung von 10 g
  
  in 100 ml DMF getropft. Nach 2 Stunden bei Raumtemperatur wird das Lösungsmittel unter Vakuum entfernt und der Rückstand mit 200 ml Diisopropylether versetzt. Der gebildete Niederschlag wird abfiltriert, mit Diisopropylether gewaschen und getrocknet. Das Rohprodukt wird durch Chromatographie an Kieselgel (Elutionsmittel: CH₂Cl₂/MeOH 9/1) gereinigt und sodann als weißes amorphes Pulver isoliert. [α]²⁰ _D = 29,8° (c = 1,28 in DMF).

The starting material can be prepared as follows:

• a)
  
  2.25 g of di-tert-butylpyrocarbonate dissolved in 30 ml of DMF are slowly added at room temperature to a solution of 10 g
  
  dropped into 100 ml of DMF. After 2 hours at room temperature, the solvent is removed under vacuum and the residue is mixed with 200 ml of diisopropyl ether. The precipitate formed is filtered off, washed with diisopropyl ether and dried. The crude product is purified by chromatography on silica gel (eluent: CH ₂ Cl ₂ / MeOH 9/1) and then isolated as a white amorphous powder. [α] ²⁰ _D = 29.8 ° (c = 1.28 in DMF).

Example 2:

enthaltende Fraktion wird auf die vorstehend für die entsprechende monomere Form beschriebene Weise behandelt. Nach dem Entfernen der Boc-Schutzgruppen erhält man die Titelverbindung: [α]²⁰ _D = –24,5° (c = 0,55, 95 % AcOH). Beispiel 3:

• a. 0,56 g
  
  0,5 mMol Fmoc-ϵ-Aminocapronsäure und 115 mg Hydroxybenzotriazol werden in 10 ml DMF gelöst und auf –30°C gekühlt. Diese Lösung wird mit einer Lösung von 115 mg Dicyclohexylcarbodiimid in 5 ml DMF (auf –10°C gekühlt) versetzt. Nach einer Reaktionszeit von 24 Stunden, wobei sich das Gemisch auf Raumtemperatur erwärmt, wird der erhaltene Dicyclohexylharnstoff abfiltriert und das Filtrat mit Wasser auf das 10-fache seines Volumens verdünnt. Das ausgefällte Reaktionsprodukt wird abfiltriert, gewaschen und über Phosphorpentoxid getrocknet. Das rohe Produkt wird ohne weitere Reinigung für die nächste Stufe eingesetzt.
• b. Fmoc-Abspaltung 0,5 g rohes Produkt der Kupplungsstufe (a) werden 10 Minuten bei Raumtemperatur mit 5 ml DMF/Piperidin 4/1 Vol./Vol. behandelt (klare Lösung) und anschließend mit 100 ml Diisopropylether vermischt. Das Reaktionsprodukt, das dabei ausfällt, wird abfiltriert, gewaschen und getrocknet. Dieses rohe Produkt wird ohne weitere Reinigung in der nächsten Stufe eingesetzt.
• c. BOC-Abspaltung 300 mg des in (1.b) erhaltenen rohen Produkts werden 5 Minuten bei Raumtemperatur mit 5 ml 100 % TFA behandelt (vollständig gelöst) und anschließend mit 50 ml Diisopropylether vermischt. Nach Zugabe von 2 ml HCl/Diethylether wird der erhaltene Niederschlag abfiltriert, gewaschen und unter Hochvakuum getrocknet. Das Endprodukt wird chromatographisch an Kieselgel (CHCl₃/MeOH/H₂O/AcOH 7/3/0,5/0,5) unter anschließender Entsalzung über Duolite (Gradient: H₂O/AcOH 95/5)---H₂O/Dioxan/AcOH 45/50/5) gereinigt. Man erhält die Titelverbindung als Acetat (weißes Lyophilisat). [α]²⁰ _D = –32° (c = 0,5, 95 % AcOH. Die erhaltene Verbindung kann gemäß dem Verfahren der Beispiele 1 und 2 zur Umsetzung mit DTPA verwendet werden.

The obtained according to Example 1, the intermediate DTPA-

containing fraction is treated in the manner described above for the corresponding monomeric form. After removal of the Boc protecting groups, the title compound is obtained: [α] ²⁰ _D = -24.5 ° (c = 0.55, 95% AcOH). Example 3:

• a. 0.56 g
  
  0.5 mmol of Fmoc-ε-aminocaproic acid and 115 mg of hydroxybenzotriazole are dissolved in 10 ml of DMF and cooled to -30 ° C. This solution is treated with a solution of 115 mg of dicyclohexylcarbodiimide in 5 ml of DMF (cooled to -10 ° C). After a reaction time of 24 hours, with the mixture warming to room temperature, the filtered dicyclohexylurea and the filtrate diluted with water to 10 times its volume. The precipitated reaction product is filtered off, washed and dried over phosphorus pentoxide. The crude product is used without further purification for the next step.
• b. Fmoc cleavage 0.5 g of crude product of coupling step (a) is incubated for 10 minutes at room temperature with 5 ml of DMF / piperidine 4/1 v / v. treated (clear solution) and then mixed with 100 ml of diisopropyl ether. The reaction product which precipitates is filtered off, washed and dried. This crude product is used in the next step without further purification.
• c. BOC elimination 300 mg of the crude product obtained in (1.b) are treated with 5 ml of 100% TFA (completely dissolved) for 5 minutes at room temperature and then mixed with 50 ml of diisopropyl ether. After addition of 2 ml of HCl / diethyl ether, the resulting precipitate is filtered off, washed and dried under high vacuum. The final product is chromatographed on silica gel (CHCl ₃ / MeOH / H ₂ O / AcOH 7/3 / 0.5 / 0.5), followed by desalting via Duolite (gradient: H ₂ O / AcOH 95/5) --- H ₂ O / dioxane / AcOH 45/50/5). The title compound is obtained as acetate (white lyophilisate). [α] ²⁰ _D = -32 ° (c = 0.5, 95% AcOH) The compound obtained can be used according to the procedure of Examples 1 and 2 for reaction with DTPA.

Example 4:

[α]²⁰ _D = –14,8° (c = 0,5, 95 % AcOH Beispiel 5:

According to the method described in Examples 1 and 3, the following LIGAND can be prepared:

[α] ²⁰ _D = -14.8 ° (c = 0.5, 95% AcOH) Example 5

wird in 5 ml 0,01 m Essigsäure gelöst. Die erhaltene Lösung wird durch ein 0,22μ Millex-GV-Filter gegeben und in 0,1 ml-Anteile aufgeteilt und bei –20°C gelagert. ¹¹¹InCl₃ (Amersham, 1 mCi/100 μl) wird mit einem gleichen Volumen an 0,5 m Natriumacetat vorverdünnt, und eine Markierung wird durchgeführt, indem man den Ligand mit der InCl₃-Lösung vermischt und bei Raumteperatur mäßig homogenisiert.1 mg

is dissolved in 5 ml of 0.01 M acetic acid. The resulting solution is passed through a 0.22μ Millex GV filter and divided into 0.1 ml portions and stored at -20 ° C. ¹¹¹ InCl ₃ (Amersham, 1 mCi / 100 μl) is prediluted with an equal volume of 0.5 M sodium acetate and labeling is performed by mixing the ligand with the InCl ₃ solution and moderately homogenizing at room temperature.

PH 7.4 HEPES buffer is then added to make a 10 ^-6 M solution.

Example 6:

, gelöst in 5 ml 0,01 m Essigsäure wird auf Raumtemperatur erwärmt und mit 1,0 mCi ⁹⁰Y in 50 μl sterilem 0,5 m Acetat versetzt. Man läßt das Gemisch 30 Minuten bis 1 Stunde stehen, um eine möglichst gute Chelatbildung zu erreichen. ⁹⁰ Y is obtained from a ⁹⁰ Sr ⁹⁰ Y radionuclide generator. The construction of the generator, its elution and the conversion of the [ ⁹⁰ Y] EDTA to the acetate complex are determined according to the method described by M. Chinol and DJ Hnatowich in J. Nucl. Med., Vol. 28 (1987), pages 1465-1470. 1 mg

, dissolved in 5 ml of 0.01 M acetic acid is warmed to room temperature and treated with 1.0 mCi ⁹⁰ Y in 50 ul sterile 0.5 m acetate. The mixture is allowed to stand for 30 minutes to 1 hour in order to achieve the best possible chelation.

A Group of INVENTIONs LIGANDS are somatostatin peptides, e.g. Somatostatin analogues that at least one of the amino acid units a chelating group containing an amide bond to the Amino group are bound, in free form or in salt form.

A Group of INVENTIONs CHELATES are the immediately before mentioned LIGANDEN, that with a detectable element, e.g. a metal ion, complexed, in free form or in salt form.

Claims (11)

Somatostatin peptides and their analogs or derivatives, the at least one chelating group for a detectable element carry, this chelating group having a terminal amino group the peptide is linked either directly or indirectly and this amino group has no significant binding activity for somatostatin receptors, and their complexes with a detectable element, in free form or in salt form. Somatostatin peptides according to claim 1, wherein the chelating Group bound to the N-terminal amino group of the somatostatin peptide is. Somatostatin peptides according to claim 1 or 2, wherein the chelating Group over an amide bond is attached to the peptide. Somatostatin peptides according to any one of the preceding claims, wherein the somatostatin peptide is derived from a compound of general formula I.

wherein AC _1-12 alkyl, C _7-10 phenylalkyl or a group of the formula RCO-, where i) R is hydrogen, C _1-11 alkyl, phenyl or C _7-10 phenylalkyl, or ii) RCO a) an L- or D-phenylalanine radical which is optionally ring-substituted by F, Cl, Br, NO ₂ , NH ₂ , OH, C _1-3 -alkyl and / or C _1-3 -alkoxy; b) the residue of a natural or synthetic α-amino acid, which differs from the above definition a), or a corresponding D-amino acid or c) a dipeptide residue in which the individual amino acid residues are identical or different and from those mentioned above under a) and / or b) defined amino acid residues are selected; A 'is hydrogen, Y ₁ and Y ₂ together form a direct bond or the radicals Y ₁ and Y ₂ each independently of one another are hydrogen B -Phe-, preferably by halogen, NO ₂ , NH ₂ , OH, C _1-3 Alkyl, and / or C _1-3 alkoxy (including pentafluoroalanine) is ring-substituted, or β-naphthyl-Ala means C (L) -Trp- or (D) -Trp-, which if given α- N-methylated and optionally substituted on the benzene ring by halogen, NO ₂ , NH ₂ , OH, C _1-3 -alkyl and / or C _1-3 -alkoxy, D Lys, Lys, in which the side chain in the β-position O is S, γ is F-Lys or δF-Lys or a 4-aminocyclohexylAla or 4-aminocyclohexylGly radical, E is Thr, Ser, Val, Phe, Ile or an aminoisobutyric acid or amino butyric acid radical, G is a radical of the formulas

where R _{7 is} hydrogen or C _1-3 -alkyl, R _{10 is} hydrogen or the radical of a physiologically tolerable, physiologically hydrolyzable ester, R _{11 is} hydrogen, C _1-3 -alkyl, phenyl or C _7-10 -phenylalkyl , R _{12 is} hydrogen, C _1-3 alkyl or a group of the formula -CH (R ₁₃ ) -X ₁ , R _{13 is} CH ₂ H, - (CH ₂ ) ₂ -OH, - (CH ₂ ) ₃ -OH or -CH (CH ₃ ) OH, or represents the substituent (including hydrogen) attached to the α-carbon atom of a natural or synthetic α-amino acid, and X _{1 represents} a group of the formula -COOR ₇ , -CH ₂ OR ₁₀ or CONR ₁₄ R ₁₅ , wherein R ₇ and R ₁₀ are as defined above, R _{14 is} hydrogen or C _1-3 alkyl and R _{15 is} hydrogen, C _1-3 alkyl, phenyl or C _7-10 phenylalkyl and R _{16 is} hydrogen or hydroxy, with the proviso that when R _{12 is} -CH (R ₁₃ ) -X ₁ , R _{11 is} hydrogen or methyl, wherein B, D and E are the L-config and the radicals in the 2- and 7-positions each independently of one another have the (L) - or (D) -configuration. Somatostatin peptides according to any one of the preceding claims, wherein the chelating group is selected from iminodicarboxyl groups, polyaminopolycarboxyl groups, groups derived from macrocyclic amines, groups of formulas IV or V

wherein R ₁ , R ₂ and R _{3 are} independently C _1-6 alkyl, C _6-8 aryl or C _7-9 arylalkyl, each optionally OH, C _1-4 alkoxy, COOH or SO ₃ H can be substituted, n 'is 1 or 2, i is an integer from 2 to 6 and TT independently of one another denote α- or β-amino acids which are linked to one another by amide bonds, groups derived from bis-aminothiol derivatives, dithiasemicarbazone derivatives, Propylenaminoximderivaten, diamiddimer captive or porphyrins are derived. Somatostatin peptide according to any one of the preceding claims, wherein the chelating group under ethylenediaminetetraacetic acid (EDTA), Diethylenetriaminepentaacetic acid (DTPA), ethylene glycol O, O'-bis (2-aminoethyl) -N, N, N ', N'-tetraacetic acid (EGTA), N, N'-bis (hydroxybenzyl) ethylenediamine-N, N'-diacetic acid (HBED), triethylenetetramine (TTHA), substituted EDTA or DTPA, 1,4,7,10-tetraazacyclododecane-N, N ', N' ', N' '' - tetraacetic acid (DOTA) and 1,4,8,11-tetraazacyclotetradecane-N, N ', N' ', N' '' - tetraacetic acid (TETA) is derived. Somatostatin peptides according to any one of the preceding claims, characterized in that the somatostatin peptide of a compound of formula

is derived. Somatostatin peptides according to any one of the preceding claims, wherein the detectable element is an α-, β-, or γ-emitting radionuclide.

labeled with ¹¹¹ In or ⁹⁰ Y, in free form or in the form of a pharmaceutically acceptable salt. Process for the preparation of the somatostatin peptides according to claim 1 to 9, characterized in that in each case in a known manner a) at least one protective group, those in a chelating group-bearing somatostatin peptide is included, removed, or b) two peptide fragments with each other connected, wherein each of the peptide fragments comprises at least one amino acid or contains an aminoalcohol in protected or unprotected form and one the two fragments containing the chelating group, wherein the amide bond is present in such a way that the desired amino acid sequence is obtained, and optionally subsequently carries out the step a) or c) a chelating group and the desired somatostatin peptide in protected or unprotected form linked together in such a way that the chelated Group is fixed to the terminal N-amino group of the peptide, and subsequently if appropriate, stage a) is carried out, or d) a functional Group of a chelant group wearing unprotected or protected peptide removed or converted into another functional group, so that another, a chelating group bearing unprotected or protected peptide obtained in the latter case, the stage a), or e) a somatostatin peptide modified with a chelating group, in which the mercapto groups of Cys residues are present in free form, oxidized, so that a Analogous is formed in which two Cys residues via an S-S bridge with each other are connected and the somatostatin peptides thus obtained in free form or in salt form, and optionally with complexed to a detectable element. A pharmaceutical composition containing a Somatostatin peptide according to any one of claims 1 to 9 together with a pharmaceutical carrier or diluents.