212Pb-labeled B7-H3-targeting antibody for pancreatic cancer therapy in mouse models

Benjamin B Kasten; Abhishek Gangrade; Harrison Kim; Jinda Fan; Soldano Ferrone; Cristina R Ferrone; Kurt R Zinn; Donald J Buchsbaum

doi:10.1016/j.nucmedbio.2017.12.004

²¹²Pb-labeled B7-H3-targeting antibody for pancreatic cancer therapy in mouse models

Nucl Med Biol. 2018 Mar:58:67-73. doi: 10.1016/j.nucmedbio.2017.12.004. Epub 2017 Dec 24.

Authors

Benjamin B Kasten¹, Abhishek Gangrade², Harrison Kim³, Jinda Fan³, Soldano Ferrone⁴, Cristina R Ferrone⁴, Kurt R Zinn⁵, Donald J Buchsbaum²

Affiliations

¹ Department of Radiology, University of Alabama at Birmingham, Birmingham, AL, United States. Electronic address: benjaminkasten@uabmc.edu.
² Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL, United States.
³ Department of Radiology, University of Alabama at Birmingham, Birmingham, AL, United States.
⁴ Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.
⁵ Institute for Quantitative Health Science and Engineering, Department of Radiology, Michigan State University, East Lansing, MI, United States.

Abstract

Introduction: We recently validated monoclonal antibody (mAb) 376.96 as an effective carrier for targeted α-particle radioimmunotherapy (RIT) with ²¹²Pb in ovarian cancer mouse models. In this study, we tested the binding of radiolabeled mAb 376.96 to human pancreatic ductal adenocarcinoma (PDAC) cells and localization in xenografts in immune-deficient mice and evaluated ²¹²Pb-labeled 376.96 (²¹²Pb-376.96) for PDAC therapy.

Methods: In vitro Scatchard assays assessed the specific binding of ²¹²Pb-376.96 to human PDAC3 adherent differentiated cells and non-adherent cancer initiating cells (CICs) dissociated from tumorspheres. In vitro clonogenic assays were used to measure the proliferation of adherent PDAC3 cells and CIC-enriched tumorspheres treated with ²¹²Pb-376.96 or the irrelevant isotype-matched ²¹²Pb-F3-C25. Mice bearing patient derived pancreatic cancer Panc039 xenografts were i.v. injected with 0.17-0.70 MBq ²¹²Pb-376.96 or isotype control ²¹²Pb-F3-C25, and used for biodistribution and tumor growth inhibition studies. Mice bearing orthotopic PDAC3 xenografts were i.v. co-injected with ^99mTc-376.96 and ¹²⁵I-F3-C25 and used for biodistribution studies.

Results: ²¹²Pb-376.96 specifically bound to PDAC3 adherent and dissociated tumorsphere CICs; K_d values averaged 9.0 and 21.7 nM, respectively, with 10⁴-10⁵ binding sites/cell. ²¹²Pb-376.96 inhibited the clonogenic survival of PDAC3 cells or CICs dissociated from tumorspheres 3-6 times more effectively than isotype-matched control ²¹²Pb-F3-C25. Panc039 s.c. tumors showed significantly higher uptake of ²¹²Pb-376.96 (14.0 ± 2.1% ID/g) compared to ²¹²Pb-F3-C25 (6.5 ± 0.9% ID/g, p < .001) at 24 h after dosing. Orthotopic PDAC3 tumors showed significantly higher uptake of ^99mTc-376.96 (6.4 ± 1.8% ID/g) compared to ¹²⁵I-F3-C25 (3.9 ± 0.9% ID/g, p < .05) at 24 h after dosing. Panc039 tumor growth was significantly inhibited by ²¹²Pb-376.96 compared to ²¹²Pb-F3-C25 or non-treated control tumors (p < .05).

Conclusion: Our results provide evidence for the efficacy of B7-H3 targeted RIT against preclinical models of pancreatic ductal adenocarcinoma (PDAC) and support future studies with ²¹²Pb-376.96 in combination with chemotherapy to potentiate efficacy against PDAC.

Keywords: (212)Pb; B7-H3; Pancreatic ductal adenocarcinoma; Radioimmunotherapy.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cell Differentiation / radiation effects
Cell Line, Tumor
Cell Transformation, Neoplastic
Female
Humans
Immunoconjugates / pharmacokinetics
Immunoconjugates / therapeutic use*
Isotope Labeling
Lead Radioisotopes*
Mice
Pancreatic Neoplasms / radiotherapy*
Radioimmunotherapy / methods*
Tissue Distribution

Substances

Immunoconjugates
Lead Radioisotopes
Lead-212

Abstract

Publication types

MeSH terms

Substances

Grants and funding