Abstract | PURPOSE: METHODS:
cMAb U36 was labelled with 211At via the linker N-succinimidyl 4-(trimethylstannyl)benzoate (SPMB). The quality of the conjugate was extensively evaluated for binding and internalisation capacity, and compared with 125I-SPMB-cMAb U36. The cellular toxicity of the astatinated conjugate was assessed in two types of in vitro growth assay and compared with 131I-labelled cMAb U36 (directly labelled). RESULTS: Comparisons between 211At-cMAb U36 and 125I-cMAb U36 demonstrated an optimal functional capacity of the labelled products. Immunoreactivity and affinity assays showed high immunoreactive fractions (>93%), and an affinity in good agreement between the astatinated and iodinated antibodies. For both conjugates, specific binding to HNSCC cells could be demonstrated, as well as some internalisation. Retention of the astatinated conjugate was just slightly lower than for the iodinated conjugate and still reasonable for therapeutic use (31+/-2% vs 42.6+/-1.0% at 22 h), demonstrating no adverse effects from astatination of the antibody. Studies on cellular toxicity demonstrated a dose-dependent and antigen-specific cellular toxicity for 211At-cMAb U36, with about 10% cell survival at 50 decays per cell. The 131I-labelled conjugate was not as efficient, with a surviving cell fraction of about 50% at 55 decays per cell. CONCLUSION: These results indicate that 211At-cMAb U36 might be a promising future candidate for eradicating HNSCC micrometastases in vivo.
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Authors | M Nestor, M Persson, G A M S van Dongen, H J Jensen, H Lundqvist, M Anniko, V Tolmachev |
Journal | European journal of nuclear medicine and molecular imaging
(Eur J Nucl Med Mol Imaging)
Vol. 32
Issue 11
Pg. 1296-304
(Nov 2005)
ISSN: 1619-7070 [Print] Germany |
PMID | 16028065
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Antibodies, Monoclonal
- Astatine
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Topics |
- Antibodies, Monoclonal
(administration & dosage, pharmacokinetics, therapeutic use)
- Astatine
(administration & dosage, pharmacokinetics, therapeutic use)
- Carcinoma, Squamous Cell
(metabolism, pathology)
- Cell Line, Tumor
- Cell Survival
(radiation effects)
- Drug Evaluation, Preclinical
- Feasibility Studies
- Head and Neck Neoplasms
(metabolism, pathology)
- Humans
- Radioimmunotherapy
(methods)
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