Radiation Physics and Engineering
A peer-reviewed journal published by K. N. Toosi University of Technology

Production and Preclinical evaluation of the 67Ga-CHX-A-DTPA-trastuzumab for HER2+ breast cancer SPECT Imaging

Document Type : Research Article

Authors

Behrouz Alirezapour 1
Mohammad Alizadeh 2
Fatemeh Badipa 1
Sana Rezaei 1

1 Radiation Application Research School, Nuclear Science and Technology Research Institute, Tehran, ‎Iran

2 Pars Isotope Company, Tehran, Iran

https://doi.org/10.22034/rpe.2025.474302.1236
Abstract
Radiolabeled monoclonal antibodies have shown great promise for cancer diagnosis and therapy. Approximately 15% to 20% of breast cancers exhibit an overexpression of a growth-promoting protein known as HER2. In the present study, trastuzumab was conjugated with CHX-A-DTPA (Macrocyclics B-355), the average number of the chelator conjugated per mAb was calculated and total concentration was determined by spectrophotometrically. CHX-A-DTPA–trastuzumab was labeled with 67Ga (10 mCi, 375 MBq) then Radiochemical purity and immunoreactivity by SKBR3 cell line and serum stability of 67Ga-CHX-A-DTPA-trastuzumab were determined. The biodistribution studies was performed in female Sprague Dowley rat (67Ga–CHX-A-DTPA–trastuzumab i.v., 200 microl, 200±20 mCi, 35±5 μg mAb , 4, 24, 48 and 72 h). 67Ga-CHX-A-DTPA-trastuzumab was prepared (RCP>98% ± 0.5, Specific activity 4.1±0.7 μCi/μg). Conjugation reaction (c/a) was 4.1±1.2. Labeling yield was 92.5% ± 2.1. Immunoreaction of 67Ga-CHX-A-DTPA- trastuzumab complex towards HER2 antigen was determined by RIA and the complex showed high immunoreactivity towards HER2. In vitro stability showed more than 91%±2.6 in the PBS and 81%±1.8 in the serum over 24 h. The Immunoreactivity of the radiolabeled anti-HER2 towards SKBR3 cell line was done by using Lindmo assay protocol which was found to be 0.84. The biodistribution of 67Ga–CHX-A-DTPA-trastuzumab complex in normal Sprague Dowley rat at 4, 24, 48, and 72 h after intravenous administration, expressed as (%ID/g). Biodistribution studies at 24 and 48 h post-injection revealed the similar pattern to the other radiolabeled anti-HER2 immunoconjugates

Highlights

  • Study of 67Ga-CHX-A-DTPA-trastuzumab were performed in this work.
  • The radioimmunoconjugate was prepared with a radiochemical purity of higher than 98±0.5% (ITLC).
  • The 67Ga-CHX-A-DTPA-trastuzumab showed high immunoreactivity towards HER2/neu antigen and SkBr3cell line.
  • In vitro stability of the labeled product was more than 91% in PBS and 81.8±1.8% in human serum over 48 hr.
  • It is a potential compound for molecular imaging of SPECT for diagnosis and follow-up of HER2 expression in oncology.

Keywords

HER2
Gallium-67
Trastuzumab
CHX-A-DTPA
Breast Cancer
Blend, M. J., Stastny, J. J., Swanson, S. M., et al. (2003). Labeling anti-HER2/neu monoclonal antibodies with 111In and 90Y using a bifunctional DTPA chelating agent. Cancer Biotherapy and Radiopharmaceuticals, 18(3):355–363.
Chappell, L., Ma, D., Milenic, D., et al. (2003). Synthesis and evaluation of novel bifunctional chelating agents based on 1, 4, 7, 10-tetraazacyclododecane-N, N, N , N-tetraacetic acid for radiolabeling proteins. Nuclear Medicine and Biology, 30(6):581–595.
Chappell, L. L., Dadachova, E., Milenic, D. E., et al. (2000). Synthesis, characterization, and evaluation of a novel bifunctional chelating agent for the lead isotopes Pb-203 and Pb-212. Nuclear Medicine and Biology, 27(1):93–100.
Cooper, M. S., Ma, M. T., Sunassee, K., et al. (2012). Comparison of 64Cu-complexing bifunctional chelators for radioimmunoconjugation: labeling efficiency, specific activity, and in vitro/in vivo stability. Bioconjugate Chemistry, 23(5):1029–1039.
Costantini, D. L., Chan, C., Cai, Z., et al. (2007). 111In-labeled trastuzumab (Herceptin) modified with nuclear localization sequences (NLS): an Auger electron-emitting radiotherapeutic agent for HER2/neu-amplified breast cancer. Journal of Nuclear Medicine, 48(8):1357–1368.
Dijkers, E. C., Kosterink, J. G., Rademaker, A. P., et al. (2009). Development and characterization of clinical grade 89Zr-trastuzumab for HER2/neu immunoPET imaging. Journal of Nuclear Medicine, 50(6):974–981.
Firestone, R. (1996). Table of Isotopes 8th Edition Vol. 1. Garmestani, K., Milenic, D. E., Plascjak, P. S., et al. (2002). A new and convenient method for purification of Y-86 using a Sr(II) selective resin and comparison of biodistribution of Y-86 and 111In labeled Herceptin. Nuclear Medicine and Biology, 29(5):599–606.
Kokai, Y., Cohen, J. A., Drebin, J. A., et al. (1987). Stage- and tissue-specific expression of the neu oncogene in rat development. Proceedings of the National Academy of Sciences, 84(23):8498–8501.
Kukis, D. L., DeNardo, G. L., DeNardo, S. J., et al. (1995). Effect of the extent of chelate substitution on the immunore-activity and biodistribution of 2IT-BAT-Lym-1 immunocon-jugates. Cancer Research, 55(4):878–884.
Leonard, D., Hill, A., Kelly, L., et al. (2002). Anti-human epidermal growth factor receptor 2 monoclonal antibody therapy for breast cancer. British Journal of Surgery, 89(3):262–271.
McDevitt, M. R., Ma, D., Simon, J., et al. (2002). Design and synthesis of Ac-225 radioimmunopharmaceuticals. Applied Radiation and Isotopes, 57(6):841–847.
Pauletti, G., Dandekar, S., Rong, H., et al. (2000). Assessment of methods for tissue-based detection of the HER-2/neu alteration in human breast cancer: a direct comparison of fluorescence in situ hybridization and immunohistochemistry. Journal of Clinical Oncology, 18(21):3651–3664.
Pippin, C. G., Parker, T. A., McMurry, T. J., et al. (1992). Spectrophotometric method for the determination of a bifunctional DTPA ligand in DTPA-monoclonal antibody conjugates. Bioconjugate Chemistry, 3(4):342–345.
Schechter, A. L., Stern, D. F., Vaidyanathan, L., et al. (1984). The neu oncogene: an erb-B-related gene encoding a 185,000-M r tumour antigen. Nature, 312(5994):513–516.
Slamon, D. J., Godolphin, W., Jones, L. A., et al. (1989). Studies of the HER-2/neu proto-oncogene in human breast and ovarian cancer. Science, 244(4905):707–712.
Smith, C. J., Gali, H., Sieckman, G. L., et al. (2003). Radiochemical investigations of 177Lu-DOTA-8-Aoc-BBN [7-14] NH2: an in vitro/in vivo assessment of the targeting ability of this new radiopharmaceutical for PC-3 human prostate cancer cells. Nuclear Medicine and Biology, 30(2):101–109.
Spiridon, C. I., Guinn, S., and Vitetta, E. S. (2004). A comparison of the in vitro and in vivo activities of IgG and F(ab)2 fragments of a mixture of three monoclonal anti-Her-2 antibodies. Clinical Cancer Research, 10(10):3542–3551.
Tang, Y., Wang, J., Scollard, D. A., et al. (2005). Imaging of HER2/neu-positive BT-474 human breast cancer xenografts in athymic mice using 111In-trastuzumab (Herceptin) Fab fragments. Nuclear Medicine and Biology, 32(1):51–58.
Tolmachev, V., Velikyan, I., Sandström, M., et al. (2010). A HER2-binding Affibody molecule labelled with Ga-68 for PET imaging: direct in vivo comparison with the 111In-labelled analogue. European Journal of Nuclear Medicine and Molecular Imaging, 37:1356–1367.
Winberg, K. J., Persson, M., Malmström, P.-U., et al. (2004). Radiobromination of anti HER2/neu/ErbB-2 monoclonal antibody using the p-isothiocyanatobenzene derivative of the [76Br] undecahydro-bromo-7, 8-dicarba-nido-undecaborate (1-) ion. Nuclear Medicine and Biology, 31(4):425–433.
Zimmermann, K., Grünberg, J., Honer, M., et al. (2003). Targeting of renal carcinoma with 67/64Cu-labeled anti-L1-CAM antibody chCE7: selection of copper ligands and PET imaging. Nuclear Medicine and Biology, 30(4):417–427.
Radiation Physics and Engineering
Volume 6, Issue 3
Spring 2025
Pages 55-61

  • Receive Date 19 August 2024
  • Revise Date 28 December 2024
  • Accept Date 19 January 2025

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