Roche secures CE mark for first companion diagnostic for VYLOY treatment in gastric and gastroesophageal cancer

Roche has introduced the VENTANAⓇ CLDN18 (43-14A) RxDx Assay, a new immunohistochemistry (IHC) companion diagnostic test that has secured CE Mark approval, making it the first of its kind to determine CLDN18 protein expression in tumors of patients with gastric or gastroesophageal junction (GEJ) adenocarcinoma. This development is crucial for identifying patients who may be suitable for treatment with Astellas’ targeted therapy, VYLOYTM (zolbetuximab).

The introduction of this assay addresses an unmet medical need, as CLDN18.2 is an emerging biomarker in gastric and GEJ cancers that can predict the potential response to targeted therapies. This assay is particularly significant as it aids in personalizing treatment plans, thereby improving patient outcomes. Matt Sause, CEO of Roche Diagnostics, highlighted the importance of this advancement, noting that gastric cancer is a major global health issue, with only a small percentage of patients with metastatic disease surviving beyond five years in Europe.

The VENTANA CLDN18 (43-14A) RxDx Assay helps determine the CLDN18.2 status in patients, guiding clinicians on the likelihood of their patients benefitting from CLDN18.2-targeted therapy. VYLOY is noted as the first treatment approved specifically for CLDN18.2-positive gastric and GEJ cancer, broadening the treatment options available for patients based on their specific disease characteristics.

Gastric cancer ranks as the fifth most common cancer globally, with higher incidence rates in Central and Eastern Europe. The disease often goes undetected until advanced stages because its symptoms are similar to those of other conditions, resulting in a lower overall survival rate of about 25% in the European Union.

The VENTANA CLDN18 (43-14A) RxDx Assay is designed to qualitatively assess the expression of Claudin 18 (CLDN18) protein in gastric and GEJ adenocarcinoma. This assay uses the OptiView DAB IHC Detection Kit for staining on a BenchMark ULTRA instrument, helping to identify patients who may be eligible for treatment with VYLOY (zolbetuximab) per the therapeutic product labelling. It measures the expression of both CLDN18 protein variants (18.1 and 18.2), with CLDN18.2 being the predominant variant in gastric and GEJ cancers.

The approval of this assay is grounded in the results of the SPOTLIGHT and GLOW clinical studies, where it served as the enrollment assay for identifying patients with CLDN18.2-positive tumors. CLDN18.2 positivity is defined as 75% or more of tumor cells showing moderate to strong membrane CLDN18 staining. These studies revealed that approximately 38% of gastric/GEJ cancer patients exhibited high levels of CLDN18, thus being considered CLDN18.2 positive by this assay. Patients treated with a combination of zolbetuximab and chemotherapy experienced a 25-31% reduction in disease progression or mortality.

Roche, established in Basel, Switzerland, in 1896, has grown to become a global leader in biotechnology and in-vitro diagnostics. The company is dedicated to scientific excellence, aiming to discover and develop medicines and diagnostics that save and improve lives worldwide. As a pioneer in personalized healthcare, Roche collaborates with various stakeholders to enhance healthcare delivery and impact. Sustainability has been a core aspect of Roche’s operations for over 125 years, with the company committed to initiatives aimed at achieving net-zero emissions by 2045.

Genentech in the United States is a wholly owned member of the Roche Group, and Roche is the majority shareholder in Chugai Pharmaceutical, Japan.