Ann-Marie Chacko1,2, Chunsheng Li3, Madhura Nayak1, John L Mikitsh1, Jia Hu3, Catherine Hou1, Luigi Grasso4, Nicholas C Nicolaides4, Vladimir R Muzykantov2, Chaitanya R Divgi1, George Coukos3. 1. Nuclear Medicine & Clinical Molecular Imaging, Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. 2. Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. 3. Ovarian Cancer Research Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. 4. Morphotek, Inc., Exton, Pennsylvania.
Abstract
UNLABELLED: Tumor endothelial marker 1 (TEM1/endosialin) is a tumor vascular marker highly overexpressed in multiple human cancers with minimal expression in normal adult tissue. In this study, we report the preparation and evaluation of (124)I-MORAb-004, a humanized monoclonal antibody targeting an extracellular epitope of human TEM1 (hTEM1), for its ability to specifically and sensitively detect vascular cells expressing hTEM1 in vivo. METHODS: MORAb-004 was directly iodinated with (125)I and (124)I, and in vitro binding and internalization parameters were characterized. The in vivo behavior of radioiodinated MORAb-004 was characterized in mice bearing subcutaneous ID8 tumors enriched with mouse endothelial cells expressing hTEM1 and by biodistribution and small-animal immuno-PET studies. RESULTS: MORAb-004 was radiolabeled with high efficiency and isolated in high purity. In vitro studies demonstrated specific and sensitive binding of MORAb-004 to MS1 mouse endothelial cells expressing hTEM1, with no binding to control MS1 cells. (125)I-MORAb-004 and (124)I-MORAb-004 both had an immunoreactivity of approximately 90%. In vivo biodistribution experiments revealed rapid, highly specific and sensitive uptake of MORAb-004 in MS1-TEM1 tumors at 4 h (153.2 ± 22.2 percentage injected dose per gram [%ID/g]), 24 h (127.1 ± 42.9 %ID/g), 48 h (130.3 ± 32.4 %ID/g), 72 h (160.9 ± 32.1 %ID/g), and 6 d (10.7 ± 1.8 %ID/g). Excellent image contrast was observed with (124)I-immuno-PET. MORAb-004 uptake was statistically higher in TEM1-positive tumors than in control tumors. Binding specificity was confirmed by blocking studies using excess nonlabeled MORAb-004. CONCLUSION: In our preclinical model, with hTEM1 exclusively expressed on engineered murine endothelial cells that integrate into the tumor vasculature, (124)I-MORAb-004 displays high tumor-to-background tissue contrast for detection of hTEM1 in easily accessible tumor vascular compartments. These studies strongly suggest the clinical utility of (124)I-MORAb-004 immuno-PET in assessing TEM1 tumor-status.
UNLABELLED: Tumor endothelial marker 1 (TEM1/endosialin) is a tumor vascular marker highly overexpressed in multiple humancancers with minimal expression in normal adult tissue. In this study, we report the preparation and evaluation of (124)I-MORAb-004, a humanized monoclonal antibody targeting an extracellular epitope of humanTEM1 (hTEM1), for its ability to specifically and sensitively detect vascular cells expressing hTEM1 in vivo. METHODS:MORAb-004 was directly iodinated with (125)I and (124)I, and in vitro binding and internalization parameters were characterized. The in vivo behavior of radioiodinated MORAb-004 was characterized in mice bearing subcutaneous ID8 tumors enriched with mouse endothelial cells expressing hTEM1 and by biodistribution and small-animal immuno-PET studies. RESULTS:MORAb-004 was radiolabeled with high efficiency and isolated in high purity. In vitro studies demonstrated specific and sensitive binding of MORAb-004 to MS1mouse endothelial cells expressing hTEM1, with no binding to control MS1 cells. (125)I-MORAb-004 and (124)I-MORAb-004 both had an immunoreactivity of approximately 90%. In vivo biodistribution experiments revealed rapid, highly specific and sensitive uptake of MORAb-004 in MS1-TEM1 tumors at 4 h (153.2 ± 22.2 percentage injected dose per gram [%ID/g]), 24 h (127.1 ± 42.9 %ID/g), 48 h (130.3 ± 32.4 %ID/g), 72 h (160.9 ± 32.1 %ID/g), and 6 d (10.7 ± 1.8 %ID/g). Excellent image contrast was observed with (124)I-immuno-PET. MORAb-004 uptake was statistically higher in TEM1-positive tumors than in control tumors. Binding specificity was confirmed by blocking studies using excess nonlabeled MORAb-004. CONCLUSION: In our preclinical model, with hTEM1 exclusively expressed on engineered murine endothelial cells that integrate into the tumor vasculature, (124)I-MORAb-004 displays high tumor-to-background tissue contrast for detection of hTEM1 in easily accessible tumor vascular compartments. These studies strongly suggest the clinical utility of (124)I-MORAb-004 immuno-PET in assessing TEM1 tumor-status.
Authors: B St Croix; C Rago; V Velculescu; G Traverso; K E Romans; E Montgomery; A Lal; G J Riggins; C Lengauer; B Vogelstein; K W Kinzler Journal: Science Date: 2000-08-18 Impact factor: 47.728
Authors: P Wesseling; R O Schlingemann; F J Rietveld; M Link; P C Burger; D J Ruiter Journal: J Neuropathol Exp Neurol Date: 1995-05 Impact factor: 3.685
Authors: Brian Tomkowicz; Katherine Rybinski; Brian Foley; Wolfgang Ebel; Brad Kline; Eric Routhier; Philip Sass; Nicholas C Nicolaides; Luigi Grasso; Yuhong Zhou Journal: Proc Natl Acad Sci U S A Date: 2007-11-06 Impact factor: 11.205
Authors: Renate Becker; Martin C Lenter; Tobias Vollkommer; Anja M Boos; Dennis Pfaff; Hellmut G Augustin; Sven Christian Journal: FASEB J Date: 2008-05-19 Impact factor: 5.191
Authors: Ann-Marie Chacko; Madhura Nayak; Colin F Greineder; Horace M Delisser; Vladimir R Muzykantov Journal: PLoS One Date: 2012-04-13 Impact factor: 3.240
Authors: Ali Keshavarz; Ahmed Alobaida; Ivan F McMurtry; Eva Nozik-Grayck; Kurt R Stenmark; Fakhrul Ahsan Journal: Mol Pharm Date: 2019-06-27 Impact factor: 4.939
Authors: Soraya M Kazuma; Deborah Sultan; Yongfeng Zhao; Lisa Detering; Meng You; Hannah P Luehmann; Dulcineia S P Abdalla; Yongjian Liu Journal: Curr Pharm Des Date: 2015 Impact factor: 3.116
Authors: Stephen P Santoro; Soorin Kim; Gregory T Motz; Dimitrios Alatzoglou; Chunsheng Li; Melita Irving; Daniel J Powell; George Coukos Journal: Cancer Immunol Res Date: 2014-10-30 Impact factor: 11.151
Authors: Chunsheng Li; Junying Wang; Jia Hu; Yi Feng; Kosei Hasegawa; Xiaohui Peng; Xingmei Duan; Aizhi Zhao; John L Mikitsh; Vladimir R Muzykantov; Ann-Marie Chacko; Daniel A Pryma; Steven M Dunn; George Coukos Journal: Oncotarget Date: 2014-08-30