FDA Greenlights Targeted Treatment for Stomach Cancer Alongside Its Companion Diagnostic Tool

FDA Greenlights Targeted Treatment for Stomach Cancer Alongside Its Companion Diagnostic Tool

In a significant development following its prior rejection in January, Astellas Pharma has gained FDA approval for Vyloy (zolbetuximab-clzb), which is intended for use in conjunction with chemotherapy as a first-line solution for locally advanced unresectable or metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma. This monoclonal antibody drug is specifically designed for tumors that present as positive for claudin (CLDN) 18.2 while being negative for the human epidermal growth factor receptor 2 (HER2).

Vyloy marks the first FDA endorsement of a treatment that specifically targets CLDN18.2, a protein that has become increasingly prominent in cancer research due to its associations with various cancers, prominently including gastric and pancreatic cancers.

The FDA’s approval was bolstered by favorable outcomes from two pivotal phase 3 clinical studies, named Glow and Spotlight, which analyzed Vyloy in combination with different chemotherapy regimens. This therapy has already received approval in several countries including Japan, the UK, South Korea, and the United States.

“The greenlighting of Vyloy in the US exemplifies our unwavering commitment to scientific advancement for serious diseases such as gastric and GEJ cancers, which are predominantly diagnosed at advanced levels. This success is the culmination of extensive research and development dedicated to targeting a new biomarker,” stated Moitreyee Chatterjee-Kishore, Senior Vice President and Head of Immuno-Oncology Development at Astellas Pharma.

At the same time, the FDA has also authorized a companion diagnostic test to help identify patients suitable for Vyloy treatment. Crafted by Roche, this immunohistochemical assay is aimed at quantifying the levels of the two CLDN18 variants (18.1 and 18.2) in cells affected by gastric and GEJ adenocarcinoma. Individuals exhibiting 75% or greater positivity of tumor cells for CLDN18.2 are classified as candidates for Vyloy therapy.

In the Glow and Spotlight trials, roughly 38% of the participants were identified as qualifying for Vyloy through this companion diagnostic approach. Patients who underwent treatment combining Vyloy with chemotherapy experienced a 25-31% decrease in disease progression or mortality risk.

“Those diagnosed with gastric or gastroesophageal junction cancer frequently find themselves at an advanced stage due to the similarity of early symptoms with various other conditions,” remarked Jill German, head of the pathology lab at Roche Diagnostics.

“Our CLDN18 companion diagnostic is aimed at pinpointing patients who qualify for targeted therapies, thus enhancing their treatment options. With the introduction of this test, Roche is committed to enhancing personalized healthcare by broadening its innovative companion diagnostic offerings.”