188Re-Labelled Anti-EGFr Humanised Monoclonal Antibody h-R3 forradioimmunotherapy

摘要

The aim of the present work was to label monoclonal antibody h-R3 with 188Re and tornassess its animal biodistribution. Materials and methods: 2-mercaptoethanol was used as a reducingrnagent. The amount of sodium glucoheptonate, ascorbic acid and stannous fluoride were varied tornachieve optimum labelling yield. Challenge against 300-fold molar excess of L-cysteine was made tornassess the stability of the tracer. Animal biodistribution study was performed at 3 and 24 h afterrnintravenous administration of 188Re-h-R3 and 99mTc-h-R3 through tale vein of male Wistar rats. A trialrnwas performed by administering into the post-operative cavity through an indwelling catheter a singlerndose 188Re-h-R3. Five patients were included. SPECT and planar images as well as multiple blood andrnurine samples were collected up to 24 h after administration of 3 mg of Mab labelled with 370 MBqrn188Re. Absorbed dose were estimated using the MIRD methodology at organ and voxel level. Results:rnRadiochemical purity of 188Re-h-R3 was 98.0±0.4%. There was not found significant differencernbetween stability of 188Re-h-R3 and 99mTc-h-R3 against cysteine challenge up to 24 h. Biodistributionrnstudy showed high radiopharmaceutical uptake in kidneys and small intestine. Urinary excretion wasrnsimilar for the antibody labelled with 188Re as well as 99mTc. Conclusions: Proposed procedurernallowed the efficient and stable labelling of h-R3 with 188Re.