Comparison of Cu-64-Complexing Bifunctional Chelators for Radioimmunoconjugation: Labeling Efficiency, Specific Activity, and in Vitro/in Vivo Stability
Maggie S Cooper, Michelle T Ma, Kavitha Sunassee, Karen P Shaw, Jennifer D Williams, Rowena L Paul, Paul S Donnelly, Philip J Blower
BIOCONJUGATE CHEMISTRY | AMER CHEMICAL SOC | Published : 2012
High radiolabeling efficiency, preferably to high specific activity, and good stability of the radioimmunoconjugate are essential features for a successful immunoconjugate for imaging or therapy. In this study, the radiolabeling efficiency, in vitro stability, and biodistribution of immunoconjugates with eight different bifunctional chelators labeled with (64)Cu were compared. The anti-CD20 antibody, rituximab, was conjugated to four macrocyclic bifunctional chelators (p-SCN-Bn-DOTA, p-SCN-Bn-Oxo-DO3A, p-SCN-NOTA, and p-SCN-PCTA), three DTPA derivatives (p-SCN-Bn-DTPA, p-SCN-CHX-A″-DTPA, and ITC-2B3M-DTPA), and a macrobicyclic hexamine (sarcophagine) chelator (sar-CO2H) = (1-NH2-8-NHCO(CH2)3..View full abstract
Awarded by EPSRC
M.S.C., K.P.S., and J.D.W. were supported by the King's College London-UCL Comprehensive Cancer Imaging Centre funded by Cancer Research UK & EPSRC, in association with MRC and DoH (UK). M.T.M. acknowledges Cancer Council Victoria for providing a Sydney Parker Smith Postdoctoral Cancer Research Fellowship; The State Government of Victoria for a Victoria Fellowship; and a Kaye Merlin Brutton Bequest. P.S.D. acknowledges financial support from the Australian Research Council. We thank Wellcome Trust for grant support to P.J.B. enabling the purchase of the PET-CT scanner. RP. was supported in part by a National Institute for Health Research (NIHR) comprehensive Biomedical Research Centre award to Guy's & St. Thomas' NHS Foundation Trust in partnership with King's College London and King's College Hospital NHS Foundation Trust, and in part by the Guy's and St. Thomas' Charity. We thank Stephen Clarke (supported by the Centre of Excellence in Medical Engineering funded by the Wellcome Trust and EPSRC under grant WT 088641/Z/09/Z) for assistance with PET/CT imaging. We thank Levente Meszeros (supported by a Cancer Research UK studentship), Alex Koers (supported by a National Institute for Health Research-funded Biomedical Research Centre studentship), and Alex O'Neill (supported by the Harris studentship) for assistance with biodistribution studies.