CLDN18 and gastroesophageal junction adenocarcinoma: Another randomized, multicenter phase IIb clinical trial, known as the FAST study (NCT01630083) [19], evaluated the efficacy of zolbetuximab in combination with epirubicin, oxaliplatin, and capecitabine (EOX) (arm 1) compared to EOX alone (arm 2) as a first-line treatment for patients with advanced gastric and gastroesophageal junction adenocarcinoma exhibiting moderate to strong CLDN18.2 expression in 40% or more of tumour cells, involving a total of 263 patients.