LH-RH peptide analogues, their uses and pharmaceutical compositions containing them

A peptide agonist or antagonist of LH-RH, of formula (I) as depicted by SEQ ID NO:

• 1:
• A1-A2-A3-A4-A5-A6-HAA-A7-Pro-Z (1)
• in which:
• A1 is pGlu, D-pGlu, Sar, N-AcSar, Pro, N-AcPro, an aromatic D-amino acid or an acylated aromatic D-amino acid;
• A2 is His, or an aromatic D-amino acid;
• A3 is an aromatic L- or D-amino acid;
• A4 is Ser, D-Ser, N-MeSer, Ser(OBut), Ser(OBzl) or Thr;
• A5 is an aromatic L-amino acid or a basic L- or D-amino acid;
• A6 is Gly, D-Pro, D-Ser, D-Thr, D-Cys, D-Met, D-Pen, D-(S-Me)Pen, D-(S-Et)Pen, D-Ser(OBut), D-Asp(OBut), D-Glu(OBut), D-Thr(OBut), D-Cys(OBut), D-His which is unsubstituted or substituted on the imidazole ring by a (C1-C6)alkyl or by a (C2-C7)acyl group, an aliphatic D-amino acid with a (C1-C8)alkyl or a (C3-C6)cycloalkyl side chain, an aromatic D-amino acid, D-cyclohexadienyl-Gly, D-perhydronaphthyl-Ala, D-perhydrodiphenyl-Ala, or a basic L- or D-amino acid;
• HAA is Ada or Npg which is unsubstituted or N-alpha substituted by a (C1-C4)alkyl;
• A7 is a basic L- or D-amino acid;
• and
• Z is GlyNH2, D-AlaNH2, azaGlyNH2, or a group —NHR2 where R2 is a (C1-C4)alkyl which is unsubstituted or substituted by one or several fluorine atoms, a (C3-C6)cycloalkyl or a heterocyclic radical selected from the group consisting of morpholinyl, pyrrolidinyl and piperidyl;
• or a pharmaceutically acceptable salt thereof.