Roche has announced the US Food and Drug Administration (FDA) approval of the VENTANA CLDN18 (43-14A) RxDx Assay for the identification of patients with gastric or gastroesophageal junction (GEJ) adenocarcinoma.
The VENTANA CLDN18 (43-14A) RxDx Assay is now claimed to be the first immunohistochemistry (IHC) companion diagnostic for measuring Claudin 18 (CLDN18) protein expression in tumours. It targets patients with gastric or GEJ adenocarcinoma.
The approval enables eligible patients to receive Tokyo-based Astellas Pharma’s targeted therapy, Vyloy (zolbetuximab). Recently, the companion diagnostic test secured CE Mark approval.
Vyloy was recently approved by the FDA for gastric or GEJ cancer.
The assay is a qualitative immunohistochemical test for assessing CLDN18 protein in gastric adenocarcinoma, including gastroesophageal junction (GEJ) adenocarcinoma.
It uses the OptiView DAB IHC Detection Kit on a BenchMark ULTRA instrument.
The Roche test measures both CLDN18 protein variants (18.1 and 18.2), with CLDN18.2 being the predominant variant in these cancers.
The new assay determines CLDN18.2 status, helping clinicians assess which patients may benefit from CLDN18.2 targeted therapy.
Vyloy is said to be the first FDA-approved treatment specifically for HER2-negative, locally advanced, unresectable, or metastatic gastric or GEJ cancer patients with CLDN18.2-positive tumours.
Roche Diagnostics pathology lab head Jill German said: “Patients who are diagnosed with gastric or gastroesophageal junction cancer are often diagnosed in an advanced stage as early symptoms can be similar across several conditions.
“Our companion diagnostic for CLDN18 can help identify patients eligible for targeted treatment and provide them with additional therapeutic options. With the launch of this test, Roche continues to advance personalised healthcare by expanding our innovative companion diagnostic portfolio.”
The VENTANA CLDN18 (43-14A) RxDx Assay received approval based on the SPOTLIGHT and GLOW clinical studies.
This assay was used to identify patients with CLDN18.2-positive tumours.
In these studies, about 38% of gastric and GEJ cancer patients had high levels of CLDN18 and were considered CLDN18.2 positive.
Patients treated with a combination of zolbetuximab and chemotherapy showed a 25-31% reduction in disease progression or death.
In April, Roche announced the CE Mark approval for the VENTANA HER2 (4B5) Rabbit Monoclonal Primary Antibody RxDx. The test is designed to identify metastatic breast cancer patients with low HER2 expression, helping to determine eligibility for Enhertu (trastuzumab deruxtecan).
