{"entity":{"id":"ventana-cldn18-43-14a","kind":"drug","name":"VENTANA CLDN18 (43-14A) RxDx Assay","aka":[],"tldr":"The stain that decides whether stomach or junction cancer is claudin 18.2-positive and so eligible for zolbetuximab.","summary":"Ventana Medical Systems' (Roche Tissue Diagnostics) CLDN18 (43-14A) RxDx Assay was approved on 18 October 2024 (PMA P230018) as the companion diagnostic for zolbetuximab in gastric or gastro-oesophageal junction adenocarcinoma.","status":"approved","asOf":"2026-11-03","links":[{"label":"FDA PMA P230018","url":"https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpma/pma.cfm?id=P230018"},{"label":"FDA: List of cleared or approved companion diagnostic devices","url":"https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools"}],"tags":["test"],"related":["cldn18-2-expression"],"cancers":["gastric"],"sections":[],"technologies":["companion-diagnostic","histopathology-ihc"],"targets":["cldn18-2"],"drugs":["zolbetuximab"],"companies":["roche-genentech"],"institutions":[],"pathways":[],"terms":["ihc","companion-diagnostic-term"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"brand":"VENTANA CLDN18 (43-14A) RxDx Assay","modality":"Immunohistochemistry companion diagnostic assay (claudin 18 protein, gastric tumour tissue)","mechanism":"Immunohistochemistry with the 43-14A antibody; the FDA list defines a positive result as claudin 18 staining in at least 75% of viable tumour cells.","approvals":[{"region":"US","year":2024,"indication":"Companion diagnostic for zolbetuximab in gastric or GEJ adenocarcinoma (claudin 18 in at least 75% of viable tumour cells)"}],"mechanismSteps":[],"toxicity":[],"access":[],"regulatoryEvents":[]},"route":"/drugs/ventana-cldn18-43-14a/","neighbours":{"biomarker":[{"id":"cldn18-2-expression","kind":"biomarker","name":"Claudin 18.2 expression (>= 75% of tumour cells, moderate to strong)","route":"/biomarkers/cldn18-2-expression/"}],"cancer":[{"id":"gastric","kind":"cancer","name":"Gastric & gastro-oesophageal junction cancer","route":"/cancers/gastric/"}],"technology":[{"id":"companion-diagnostic","kind":"technology","name":"Companion diagnostics","route":"/technologies/companion-diagnostic/"},{"id":"histopathology-ihc","kind":"technology","name":"Histopathology & immunohistochemistry","route":"/technologies/histopathology-ihc/"}],"target":[{"id":"cldn18-2","kind":"target","name":"Claudin 18.2","route":"/targets/cldn18-2/"}],"drug":[{"id":"zolbetuximab","kind":"drug","name":"Zolbetuximab","route":"/drugs/zolbetuximab/"}],"company":[{"id":"roche-genentech","kind":"company","name":"Roche / Genentech","route":"/companies/roche-genentech/"}],"term":[{"id":"companion-diagnostic-term","kind":"term","name":"Companion diagnostic","route":"/terms/companion-diagnostic-term/"},{"id":"ihc","kind":"term","name":"Immunohistochemistry (IHC)","route":"/terms/ihc/"}]}}