Preclinical and first-in-human evaluation of 18F-labeled D-peptide antagonist for PD-L1 status imaging with PET.

Abstract

PURPOSE:

PD-L1 PET imaging allows for the whole body measuring its expression across primary and metastatic tumors and visualizing its spatiotemporal dynamics before, during, and after treatment. In this study, we reported a novel 18F-labeled D-peptide antagonist, 18F-NOTA-NF12, for PET imaging of PD-L1 status in preclinical and first-in-human studies.

METHODS:

Manual and automatic radiosynthesis of 18F-NOTA-NF12 was performed. Cell uptake and binding assays were completed in MC38, H1975, and A549 cell lines. The capacity for imaging of PD-L1 status, biodistribution, and pharmacokinetics were investigated in preclinical models. The PD-L1 status was verified by western blotting, immunohistochemistry/fluorescence, and flow cytometry. The safety, radiation dosimetry, biodistribution, and PD-L1 imaging potential were evaluated in healthy volunteers and patients.

RESULTS:

The radiosynthesis of 18F-NOTA-NF12 was achieved via manual and automatic methods with radiochemical yields of 41.7 ± 10.2 % and 70.6 ± 4.2 %, respectively. In vitro binding assays demonstrated high specificity and affinity with an IC50 of 78.35 nM and KD of 85.08 nM. The MC38 and H1975 tumors were clearly visualized with the optimized tumor-to-muscle ratios of 5.36 ± 1.17 and 7.13 ± 1.78 at 60 min after injection. Gemcitabine- and selumetinib-induced modulation of PD-L1 dynamics was monitored by 18F-NOTA-NF12. The tumor uptake correlated well with their PD-L1 expression. 18F-NOTA-NF12 exhibited renal excretion and rapid clearance from blood and other non-specific organs, contributing to high contrast imaging in the clinical time frame. In NSCLC and esophageal cancer patients, the specificity of 18F-NOTA-NF12 for PD-L1 imaging was confirmed. The 18F-NOTA-NF12 PET/CT and 18F-FDG PET/CT had equivalent findings in patients with high PD-L1 expression.

CONCLUSION:

18F-NOTA-NF12 was developed successfully as a PD-L1-specific tracer with promising results in preclinical and first-in-human trials, which support the further validation of 18F-NOTA-NF12 for PET imaging of PD-L1 status in clinical settings.

• Authors: Ming Zhou, Xiaobo Wang, Bei Chen, Shijun Xiang, Wanqian Rao, Zhe Zhang, Huanhuan Liu, Jianyang Fang, Xiaoqin Yin, Pengbo Deng, Xianzhong Zhang, Shuo Hu
• Journal: European journal of nuclear medicine and molecular imaging (Eur J Nucl Med Mol Imaging) Vol. 49 Issue 13 Pg. 4312-4324 (Nov 2022) ISSN: 1619-7089 [Electronic] Germany
• PMID: 35831714 (Publication Type: Journal Article)
• Copyright: © 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

Chemical References

• B7-H1 Antigen
• Fluorine Radioisotopes
• Fluorodeoxyglucose F18
• Peptides

Topics

• Humans
• B7-H1 Antigen (metabolism)
• Fluorine Radioisotopes
• Fluorodeoxyglucose F18
• Tissue Distribution
• Positron Emission Tomography Computed Tomography
• Cell Line, Tumor
• Positron-Emission Tomography (methods)
• Peptides (metabolism)