Astellas Pharma's zolbetuximab, branded Vyloy, receives FDA approval for first-line treatment of advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma expressing CLDN18.2, offering a new targeted therapy for HER2-negative cases. Vyloy, acquired from Ganymede Pharmaceuticals, demonstrated significant improvements in progression-free and overall survival in Phase 3 trials, with common side effects including nausea, vomiting, and decreased appetite.