If gastroesophageal cancer does not respond to first-line zolbetuximab, experts advise against continuing it with a new chemo backbone. This is based on tumor heterogeneity and parallels with a negative trial of continuing trastuzumab past progression in HER2+ disease.
Experienced oncologists are omitting the standard loading dose of Zolbetuximab, suspecting it causes acute gastritis. They start directly with the maintenance dose, reporting better patient tolerance. This off-label practice is now being investigated in a randomized trial.
In the increasingly common scenario of gastric cancer with multiple biomarkers (HER2, PD-L1, Claudin), experts recommend a clear hierarchy. Based on data maturity, HER2-targeted therapy is the first choice, followed by PD-L1 immunotherapy, with Claudin-targeted therapy third.
For highly symptomatic gastric cancer patients needing rapid cytoreduction, oncologists may initiate treatment with chemotherapy alone. This approach aims to quickly control the disease and avoids confounding potential drug toxicities with rapid progression before adding biomarker-driven agents.