La Trobe
Engineering anti-Lewis-Y hu3S193 antibodies with improved therapeutic ratio for radioimmunotherapy of epithelial cancers 2016.pdf (1.57 MB)

Engineering anti-Lewis-Y hu3S193 antibodies with improved therapeutic ratio for radioimmunotherapy of epithelial cancers

Download (1.57 MB)
journal contribution
posted on 2021-08-12, 06:43 authored by IJG Burvenich, Fook-Thean LeeFook-Thean Lee, GJ O'Keefe, D Makris, D Cao, Sylvia GongSylvia Gong, Angela RigopoulosAngela Rigopoulos, LC Allan, MW Brechbiel, Z Liu, PA Ramsland, Andrew ScottAndrew Scott
Background: The aim of the study was to explore Fc mutations of a humanised anti-Lewis-Y antibody (IgG1) hu3S193 as a strategy to improve therapeutic ratios for therapeutic payload delivery. Methods: Four hu3S193 variants (I253A, H310A, H435A and I253A/H310A) were generated via site-directed mutagenesis and radiolabelled with diagnostic isotopes iodine-125 or indium-111. Biodistribution studies in Lewis-Y-positive tumour-bearing mice were used to calculate the dose in tumours and organs for therapeutic isotopes (iodine-131, yttrium-90 and lutetium-177). Results: 111In-labelled I253A and H435A showed similar slow kinetics (t1/2β, 63.2 and 62.2 h, respectively) and a maximum tumour uptake of 33.11 ± 4.05 and 33.69 ± 3.77 percentage injected dose per gramme (%ID/g), respectively. 111In-labelled I253A/H310A cleared fastest (t1/2β, 9.1 h) with the lowest maximum tumour uptake (23.72 ± 0.85 %ID/g). The highest increase in tumour-to-blood area under the curve (AUC) ratio was observed with the metal-labelled mutants (90Y and 177Lu). 177Lu-CHX-A" DTPA-hu3S193 I253A/H310A (6:1) showed the highest tumour-to-blood AUC ratio compared to wild type (3:1) and other variants and doubling of calculated dose to tumour based on red marrow dose constraints. Conclusions: These results suggest that hu3S193 Fc can be engineered with improved therapeutic ratios for 90Y- and 177Lu-based therapy, with the best candidate being hu3S193 I253A/H310A for 177Lu-based therapy.


Publication Date



EJNMMI Research





Article Number



13p. (p. 1-13)





Rights Statement

The Author reserves all moral rights over the deposited text and must be credited if any re-use occurs. Documents deposited in OPAL are the Open Access versions of outputs published elsewhere. Changes resulting from the publishing process may therefore not be reflected in this document. The final published version may be obtained via the publisher’s DOI. Please note that additional copyright and access restrictions may apply to the published version.