Radiolabeled compounds for in vivo imaging of gastrin-releasing peptide receptor (grpr) and treatment of grpr-related disorders

There is provided peptidic compounds of Formula I, A or B(Rradn6-[linker]-RL-Xaa1-Xaa2-Xaa3-Xaa4-Xaa5-Xaa6-Xaa7-Xaa8-ψ-Xaa9-NH2). Xaa1 is D-Phe, Cpa, D-Cpa, Nal, D-Nal, 2-Nal, or D-2-Nal; Xaa2 is Asn, Gln, Hse, Cit or His. Xaa3 is Trp, Bta, Trp(Me), Trp(7-Me), Trp(6-Me), Trp(5-Me), Trp(4-Me), Trp(2-Me), Trp(7-F), Trp(6-F), Trp(5-F), Trp(4-F), Trp(5-OH), or αMe-Trp. Xaa4 is Ala or Ser. Xaa5 is Val, Cpg, or Tle. Xaa6 is Gly, NMe-Gly, or D-Ala. Xaa7 is His or NMe-His. Xaa8 is Leu or Phe. Xaa9-NH2 is a C-terminally amidated amino acid residue selected from Pro, 4-oxa-L-Pro, Me2 Thz, or Thz. ψ represents a peptide bond or reduced peptide bond joining Xaa8 to Xaa9. Rradn6 is 1-5 radiolabeling groups. There is also provided the use of such compounds as imaging agents or therapeutic agents.