A kit method for the high level synthesis of [211At]MABG

Bioorg Med Chem. 2007 May 15;15(10):3430-6. doi: 10.1016/j.bmc.2007.03.016. Epub 2007 Mar 12.


meta-[(211)At]Astatobenzylguanidine ([(211)At]MABG), an analogue of meta-iodobenzylguanidine (MIBG) labeled with the alpha-emitter (211)At, targets the norepinephrine transporter. Because MABG has been shown to have excellent characteristics in preclinical studies, it has been considered to be a promising targeted radiotherapeutic for the treatment of tumors such as micrometastatic neuroblastoma that overexpress the norepinephrine transporter. To facilitate clinical evaluation of this agent, a convenient method for the high level synthesis of [(211)At]MABG that is adaptable for kit formulation has been developed. A tin precursor anchored to a solid-support was treated with a methanolic solution of (211)At in the presence of a mixture of H(2)O(2)/HOAc as the oxidant; [(211)At]MABG was isolated by simple solid-phase extraction. By using C-18 solid-phase extraction, the radiochemical yield from 25 batches was 63+/-13%; however, loss of radioactivity during evaporation of the methanolic solution was a problem. This difficulty was avoided by use of a cation exchange resin cartridge for isolation of [(211)At]MABG, which resulted in radiochemical yields of 63+/-9% in a shorter duration of synthesis. The radiochemical purity was more than 90% and no chemical impurity has been detected. The final doses were sterile and apyrogenic. These results demonstrate that [(211)At]MABG can be prepared via a kit method at radioactivity levels anticipated for initiation of clinical studies.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • 3-Iodobenzylguanidine / chemical synthesis*
  • Astatine / chemistry*
  • Chromatography, High Pressure Liquid
  • Chromatography, Ion Exchange
  • Chromatography, Thin Layer
  • Guanidine / analogs & derivatives*
  • Guanidine / chemical synthesis
  • Half-Life
  • Indicators and Reagents
  • Isotope Labeling
  • Quality Control
  • Radioisotopes / chemistry
  • Radiopharmaceuticals / chemical synthesis*
  • Spectrophotometry, Ultraviolet
  • Tin / chemistry


  • Indicators and Reagents
  • Radioisotopes
  • Radiopharmaceuticals
  • meta-((211)At)astatobenzylguanidine
  • 3-Iodobenzylguanidine
  • Tin
  • Guanidine
  • Astatine