Patent ID: 7326685

Claim:
A peptide agent having the formula: X-Y-Z-Q, wherein: X is selected from the group consisting of cytotoxic agents, therapeutic agents, detectable labels, and chelating groups; Y is a peptide that increases the hydrophilic biodistribution of said agent, a hydrophilic polymer that includes a linker for X, or is omitted; Q is a somatostatin peptide or analog thereof having biological activity; and Z is D-Ser-Nle-D-Tyr-D-Ser-c[Cys-Phe-D-Trp-Lys-Thr-Cys]-Thr-NH 2 , a linking peptide that, when bonded to Q at the N-terminus or at a compatible side-chain amino group of Q, preserves at least 50% of the biological activity of Q.