Real-world implementation of a standardized administration protocol for zolbetuximab-associated nausea and vomiting:...

Zolbetuximab frequently causes infusion-related nausea and vomiting, which may lead to infusion interruption in routine practice. We developed and implemented a standardized institutional protocol for zolbetuximab administration and chemotherapy-induced nausea and vomiting (CINV) management.

This single-center retrospective descriptive cohort study included all consecutive eligible patients with unresectable or recurrent, HER2-negative, CLDN18.2-positive advanced gastric, or gastroesophageal junction adenocarcinoma who received zolbetuximab-containing chemotherapy between June 2024 and December 2025. The protocol incorporated structured antiemetic prophylaxis and real-time nausea assessment using the Wong-Baker FACES® Rating Scale (FRS). FRS ≥ 3 was used as an institutional operational threshold for temporary interruption and stepwise re-initiation; it was not intended to be formally equivalent to CTCAE grade 2 nausea.

Seventeen consecutive patients were included, and no eligible patients were excluded after screening. During cycle 1, the acute-phase total control (TC) rate was 70.6% (12/17; 95% CI, 44.0-89.7). TC rates during the delayed, ultra-delayed, and overall phases were 70.6%, 82.4%, and 70.6%, respectively. Complete response rates were 100.0% in the acute phase and remained above 94% across all phases. Temporary infusion interruption occurred in 4 patients (23.5%); 3 interruptions (17.6%) were attributed to nausea and 1 (5.9%) to severe epigastric pain. All planned infusions were completed. Serum albumin showed a transient decline during early cycles followed by gradual recovery.

In this small, non-comparative retrospective cohort, protocol-based zolbetuximab administration was feasible in routine practice, and all patients completed the planned cycle 1 infusion. Albumin findings and survival outcomes should be interpreted as exploratory and hypothesis-generating.