A peptide conjugate having the formula I: R1 &ndash Z &ndash L &ndash Y &ndash R2 wherein R1 is H, C1-4 alkyl, acetyl, formyl, benzoyl or trifluoroacetyl Z is a peptide sequence having the formula IVa His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Z9-Leu-Ser-Z12-GI n-Met-Glu-Z 16-Glu-Ala-Val-Arg-Leu-PheIle- Glu-Trp-Leu-Z27-Z28 (IVa) wherein Z9 is selected from Glu and Asp Z12 is selected from Lys and Orn Z16 is selected from Glu and Lys Z27 is selected from Lys and Orn Z28 is selected from Asn and Asp or is absent L is a peptide sequence having the formula IVb L 1-L2-L3-L4 (IVb) wherein L 1 is selected from Peg3, Gin, Cys, Lys and Orn or is absent L2 is selected from Peg3, Gin, Cys, Lys and Orn or is absent L3 is selected from Peg3, Gin, Cys, Lys and Orn or is absent L4 is selected from Peg3, Gin, Cys, Lys and Orn or is absent Y is a peptide sequence having the formula IVc Y12-Y13-Trp-Leu-Asp-Phe (IVc) wherein Y12 is Tyr or is absent and Y13 is Gly or is absent or a pharmaceutically acceptable salt or solvate thereof.
