title: Pharmaceutical and clinical development of phosphonate-based radiopharmaceuticals for the targeted treatment of bone metastases.
abstract: Therapeutic phosphonate-based radiopharmaceuticals radiolabeled with beta, alpha and conversion electron emitting radioisotopes have been investigated for the targeted treatment of painful bone metastases for >35years. We performed a systematic literature search and focused on the pharmaceutical development, preclinical research and early human studies of these radiopharmaceuticals. The characteristics of an ideal bone-targeting therapeutic radiopharmaceutical are presented and compliance with these criteria by the compounds discussed is verified. The importance of both composition and preparation conditions for the stability and biodistribution of several agents is discussed. Very few studies have described the characterization of these products, although knowledge on the molecular structure is important with respect to in vivo behavior. This review discusses a total of 91 phosphonate-based therapeutic radiopharmaceuticals, of which only six agents have progressed to clinical use. Extensive clinical studies have only been described for (186)Re-HEDP, (188)Re-HEDP and (153)Sm-EDTMP. Of these, (153)Sm-EDTMP represents the only compound with worldwide marketing authorization. (177)Lu-EDTMP has recently received approval for clinical use in India. This review illustrates that a thorough understanding of the radiochemistry of these agents is required to design simple and robust preparation and quality control methods, which are needed to fully exploit the potential benefits of these theranostic radiopharmaceuticals. Extensive biodistribution and dosimetry studies are indispensable to provide the portfolios that are required for assessment before human administration is possible. Use of the existing knowledge collected in this review should guide future research efforts and may lead to the approval of new promising agents.
authors: Department of Clinical Pharmacy, Meander Medical Center, Amersfoort, The Netherlands. Electronic address: r.lange@meandermc.nl.
authors: Rogier
authors: R
authors: Lange
authors: Department of Pharmacy, Radboud Medical Center, Nijmegen, The Netherlands; Department of Nuclear Medicine, Meander Medical Center, Amersfoort, The Netherlands.
authors: Rob
authors: R
authors: Ter Heine
authors: Medical Radioisotope Program, Nuclear Security and Isotope Division, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN, USA.
authors: Russ Ff
authors: RF
authors: Knapp
authors: Department of Nuclear Medicine, Meander Medical Center, Amersfoort, The Netherlands.
authors: John M H
authors: JM
authors: de Klerk
authors: Department of Internal Medicine/Medical Oncology, Meander Medical Center, Amersfoort, The Netherlands; Department of Medical Oncology, University Medical Center, Utrecht, The Netherlands.
authors: Haiko J
authors: HJ
authors: Bloemendal
authors: Department of Clinical Pharmacology & Pharmacy, VU University Medical Center, Amsterdam, The Netherlands; Department of Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands.
authors: N Harry
authors: NH
authors: Hendrikse
mesh_terms: D000818:Animals; D001859:Bone Neoplasms / Q000188:drug therapy* / Q000556:secondary*; D055808:Drug Discovery; D006801:Humans; D058990:Molecular Targeted Therapy; D063065:Organophosphonates / Q000737:chemistry / Q000627:therapeutic use*; D019275:Radiopharmaceuticals / Q000737:chemistry / Q000627:therapeutic use*
chemical_list: D063065:Organophosphonates; D019275:Radiopharmaceuticals
keywords: Alpha emitters; Beta emitters; Bone metastases; Conversion electron emitters; Phosphonates; Therapeutic bone-targeting radiopharmaceuticals