Preclinical evaluation of a radioiodinated fully human antibody for in vivo imaging of vascular adhesion protein-1-positive vasculature in inflammation

  • J Nucl Med. 2013 Aug;54(8):1315-9. doi: 10.2967/jnumed.113.120295.
Anu Autio  1 ,  Petri J Vainio ,  Sami Suilamo ,  Antti Mali ,  Jani Vainio ,  Tiina Saanijoki ,  Tommi Noponen ,  Helena Ahtinen ,  Pauliina Luoto ,  Mika Teräs ,  Sirpa Jalkanen ,  Anne Roivainen
Affiliations
  • 1. Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
PMID: 23847292 DOI: 10.2967/jnumed.113.120295
Abstract

Vascular adhesion protein-1 (VAP-1) is an endothelial glycoprotein mediating leukocyte trafficking from blood to sites of inflammation. BTT-1023 is a fully human monoclonal anti-VAP-1 antibody developed to treat inflammatory diseases. In this study, we preclinically evaluated radioiodinated BTT-1023 for inflammation imaging.

Methods: Rabbits were intravenously injected with radioiodinated BTT-1023. Distribution and pharmacokinetics were assessed by PET/CT up to 72 h after injection. Human radiation dose estimates for (124)I-BTT-1023 were extrapolated. Additionally, rabbits with chemically induced synovitis were imaged with (123)I-BTT-1023 SPECT/CT.

Results: Radioiodinated BTT-1023 cleared rapidly from blood circulation and distributed to liver and thyroid. Inflamed joints were delineated by SPECT/CT. The estimated human effective dose due to (124)I-BTT-1023 was 0.55 mSv/MBq, if blockage of thyroid uptake is assumed.

Conclusion: The radioiodinated BTT-1023 was able to detect mild inflammation in vivo. Clinical (124)I-BTT-1023 PET studies with injected radioactivity of 0.5-0.7 MBq/kg may be justified.

Keywords
antibody; nuclear imaging; rabbit; radioiodination; vascular adhesion protein-1.
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