Abstract: Novel oligopeptides are disclosed for in vivo tumor imaging and therapy. The novel oligopeptides are oligopeptides containing from 4 to 50 peptide units containing as a characteristic triplet therein the amino acid sequence leu-asp-val (LDV), which triplet provides the oligopeptide with a strong in vivo binding affinity for LDV binding sites on tumors and other tissues. For diagnostic purposes the oligopeptides are labelled with a radioactive label, e.g. .sup.125 I, whilst for therapeutic purposes the oligopeptides are chemically linked to or conjugated with a cytotoxin, such as the ricin A-chain.

Abstract: The peptide EPPT (Glu-Pro-Pro-Thr)(SEQ I YD NO:1) selectively binds a mucin expressed by epithelial tumors. It may be incorporated into larger molecules, such as peptides consisting of the sequence EPPT and further amino acids to form a peptide of up to 30 amino acids, and may be radiolabelled or used to guide toxins, etc. to cells expressing the mucin.

Abstract: Radioactively labelled peptides comprising oligopeptides of from 3 to 10 peptide units and containing the sequence RGD and particularly the oligopeptides RGDSY and RGDFY, are disclosed as in vivo thrombus, tumor or CAM markers for the in vivo diagnosis and detection of thrombi, tumors or CAM in mammals.