Metal complexes of bleomycin: Evaluation of [Rh-105]-bleomycin for use in targeted radiotherapy

Bleomycin has been used as a carrier for several radioisotopes; however, it s potential for clinical use has been limited either by the in vivo stabili ty of the complexes or the half-life of the isotope used. The chemical, bio logical, and radiological properties of (105)Rhodium appear to make it an i deal choice for targeted radiotherapy. The synthesis and purification of a hereto unreported (105)Rhodium-bleomycin (Rh-105-BLM) complex is described. The stability of this complex in plasma is sufficient to allow targeted de livery of the radioisotope. (57)Cobalt-bleomycin was studied under identica l conditions for comparative purposes. The suitability of Rh-105-BLM for ta rgeted therapy, which appears to be limited by the renal clearance of this agent, is discussed. NUCL MED BIOL 26;4:421-430, 1999. (C) 1999 Elsevier Sc ience Inc. All rights reserved.