Video Description Title
Video Description description
Claudins are present throughout the body, but 2 specific isoforms of CLDN18 are localised to certain tissue types5,6
CLDN18.1
CLDN18.1 is the dominant isoform in normal and malignant lung tissue.
CLDN18.2
CLDN18.2 is the dominant isoform in normal gastric tissue and is often retained in malignant transformation.
Matteo Fassan, MD, PhD
CONFINED IN HEALTHY TISSUE
RETAINED AND EXPOSED IN MALIGNANT TRANSFORMATION
MAINTAINED IN METASTATIC PROGRESSION
According to 2 recent global studies in patients with locally advanced unresectable or metastatic G/GEJ adenocarcinoma, ~38% of cases demonstrated ≥75% of tumour cells with moderate-to-strong (2+/3+) membranous CLDN18 staining.11,12
*The overall global 5-year survival rate for patients diagnosed with stage III G/GEJ is 10% and for stages IV patients 5%.17,18
†Locally advanced (stage II and III) and metastatic (stage IV) G/GEJ cancer per TNM staging classification as described in NCCN Guidelines.19,20
CLDN18.1, claudin 18 isoform 1; CLDN18.2, claudin 18 isoform 2; dMMR, deficient mismatch repair; ESMO, European Society for Medical Oncology; GCs, gastric cancers; GECs, gastroesophageal cancers; G/GEJ, gastric/gastroesophageal junction; HER2, human epidermal growth factor receptor-2; IHC, immunohistochemistry; PD-L1, programmed death ligand 1; TNM, tumour node metastases.
Data from 2 single-institution studies. The first study was undertaken in Padua, Italy and included a large series of advanced GCs (n=280) and GECs (n=70).1 The second study was undertaken in 408 Japanese patients with advanced G/GEJ cancers.16
*Times varied between collection of archival and baseline samples (21 to 1306 days).
Data in patients with G/GEJ cancers suggest that CLDN18.2 expression demonstrated high concordance between primary and metastatic tumour samples.9
In a study of 523 primary G/GEJ adenocarcinomas and 135 pair-matched, synchronous modal metastases9:
As is the case with other biomarkers such as HER2, CLDN18.2 expression may demonstrate variability within a tumour, and this should be taken into account when sampling.9,22
In the same study that demonstrated high-level concordance between primary and metastatic samples, intratumoural heterogeneity in terms of CLDN18.2 expression was found in9:
of primary GC tumours
of primary GEC tumours
of nodal metastases
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References: 1. Pellino A, Brignola S, Riello E, et al. Association of CLDN18 protein expression with clinicopathological features and prognosis in advanced gastric and gastroesophageal junction adenocarcinomas. J Pers Med 2021;11(11):1095. 2. Tsukita S, Tanaka H, Tamura A. The claudins: from tight junctions to biological systems. Trends Biochem Sci 2019;44(2):141-52. 3. Hu YJ, Wang YD, Tan FQ, Yang WX. Regulation of paracellular permeability: factors and mechanisms. Mol Biol Rep 2013;40:6123-42. 4. Lordick F, Candia Montero L, Castelo-Branco L, et al. Ann Oncol 2022;33(10):1005-1020. ESMO Gastric Cancer Living Guideline.v1.2 ed October 2023. Available at https://www.esmo.org/living-guidelines/esmo-gastric-cancer-living-guideline. Accessed 03.05.2024. 5. Sahin U, Koslowski M, Dhaene K, et al. Claudin-18 splice variant 2 is a pan-cancer target suitable for therapeutic antibody development. Clin Cancer Res 2008;14(23):7624-34. 6. Niimi T, Nagashima K, Ward JM, et al. Claudin-18, a novel downstream target gene for the T/EBP/NKX2.1 homeodomain transcription factor, encodes lung- and stomach-specific isoforms through alternative splicing. Mol Cell Biol 2001;21(21):7380-90. 7. Sahin U, Schuler M, Richly H, et al. A phase I dose-escalation study of IMAB362 (Zolbetuximab) in patients with advanced gastric and gastro-oesophageal junction cancer. Eur J Cancer 2018;100:17-26. 8. Lamouille S, Xu J, Derynck R. Molecular mechanisms of epithelial-mesenchymal transition. Nat Rev Mol Cell Biol 2014;15(3):178–96. 9. Coati I, Lotz G, Fanelli GN, et al. Claudin-18 expression in oesophagogastric adenocarcinomas: a tissue microarray study of 523 molecularly profiled cases. Br J Cancer 2019;121(3):257-63. 10. Rohde C, Yamaguchi R, Mukhina S, Sahin U, Itoh K, Türeci O. Comparison of claudin 18.2 expression in primary tumors and lymph node metastases in Japanese patients with gastric adenocarcinoma. Jpn J Clin Oncol 2019;49(9):870-6. 11. Shitara K, Lordick F, Bang YJ, et al. Zolbetuximab plus mFOLFOX6 in patients with CLDN18.2-positive, HER2-negative, untreated, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma (SPOTLIGHT): a multicentre, randomised, double-blind, phase 3 trial. Lancet 2023;401(10389):1655-68. 12. Shah MA, Shitara K, Ajani JA, et al. Zolbetuximab plus CAPOX in CLDN18.2-positive gastric or gastroesophageal junction adenocarcinoma: the randomized, phase 3 GLOW trial. Nat Med. 2023;29(8): 2133-2141. 13. Van Cutsem E, Bang YJ, Feng-yi F, et al. HER 2 screening data from ToGA: targeting HER2 in gastric and gastroesophageal junction cancer. Gastric Cancer 2015;18:476-84. 14. Fuchs Cs, Ozguroglu M, Bang YJ, et al. Pembrolizumab versus paclitaxel for previously treated PD-L1-positive advanced gastric or gastroesophageal junction cancer: 2-year update of the randomized phase 3 KEYNOTE-061 trial. Gastric Cancer 2022;25:197-206. 15. Abrahao-Machado LF, Scapulatempo-Neto C. HER2 testing in gastric cancer: an update. World J Gastroenterol 2016;22(19):4619-25. 16. Kubota Y, Kawazoe A, Mishima S, et al. Comprehensive clinical and molecular characterization of claudin 18.2 expression in advanced gastric or gastroesophageal junction cancer. ESMO Open 2023;8(1):100762. 17. Casamayor M, Morlock R, Maeda H, Ajani J. Targeted literature review of the global burden of gastric cancer. Ecancermedicalscience 2018;12:883. eCollection 2018. 18. Larønningen S, Ferlay J, Beydogan H, et al (2022). NORDCAN: Cancer Incidence, Mortality, Prevalence and Survival in the Nordic Countries, Version 9.2 (23.06.2022). Association of the Nordic Cancer Registries. Cancer Registry of Norway. Available from: https://nordcan.iarc.fr/en/dataviz/survival_table?sexes=2. Accessed 03.05.2024. 19. Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Gastric Cancer V.1.2023. National Comprehensive Cancer Network, Inc. 2023. All rights reserved. Accessed 03.05.2024. To view the most recent and complete version of the guideline, go online to NCCN.org. 20. Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Esophageal and Esophagogastric Junction Cancers V.2.2023. National Comprehensive Cancer Network, Inc. 2023. All rights reserved. To view the most recent and complete version of the guideline, go online to NCCN.org. Accessed 03.05.2024. 21. Shitara K, Xu R, Moran D, et al. Global prevalence of CLDN18.2 in patients with locally advanced (LA) unresectable or metastatic gastric or gastroesophageal junction (mG/GEJ) adenocarcinoma: Biomarker analysis of two zolbetuximab phase 3 studies (SPOTLIGHT and GLOW). Presented at the 2023 ASCO Annual Meeting; June 2-6, 2023; Chicago, IL, USA. 22. Cao W, Xing H, Li Y, et al. Claudin18.2 is a novel molecular biomarker for tumor‑targeted immunotherapy. Biomarker Research 2022;10:38. 23. Grillo F, Fassan M, Sarocchi F, et al. HER2 heterogeneity in gastric/gastroesophageal cancers: from benchside to practice. World J Gastroenterol 2016;22(26):5879-87.