Evaluation of biomolecules for metabolic radiotherapy

We evaluated several biomolecules as radiotherapeutical agents, such as the antibodies ior-CEA1 and an anti-CEA fragment scFv, as well as the peptides ior-P1394, lanreotide and DOTA-lanreotide (MAURITIUS). The first three agents were synthesized and obtained by our group and the others were supplied by the IAEA. The synthesis of ior-P1394, containing a peptide sequence AGGGβA as chelator for 188Re is described. Except MAURITIUS, all other agents were first evaluated with 99Tcm, attaining a yield of >90%. Likewise the 188Re evaluation exhibited yields of >90% labelling efficiency without major effects on in vitro stability for all agents, except the scFv, which was not evaluated with 188Re. For DOTA-lanreotide, it was only obtained up to 83% labelling efficiency with 90Y. (author)