A Phase II Clinical Trial Evaluating the Antiemetic Effect and Safety of a Five-Drug Combination Therapy for Zolbetuximab, Including Olanzapine and Antihistamines, with or without Pre-Treatment Olanzapine

A Phase II Clinical Trial Evaluating the Antiemetic Effect and Safety of a Five-Drug Combination Therapy for Zolbetuximab, Including Olanzapine and Antihistamines, with or without Pre-Treatment Olanzapine - OPTIMIZE:WJOG19524G

Status

Recruiting

Phases

Phase 2

Study type

Interventional

Source

JPRN

Registry ID

JPRN-jRCTs041250124

Enrollment

Registered

2025-10-31

Start date

2025-11-04

Completion date

Unknown

Last updated

2026-09-14

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

HER2-negative and CLDN-positive unresectable advanced recurrent gastric or gastro-oesophageal juncti HER2-negative,CLDN-positive,unresectable advanced recurrent gastric or gastro-oesophageal juncti

Interventions

Previous day pre-sleep olanzapine non-administration group 5-HT3 receptor antagonist + steroid + NK1 receptor antagonist + antihistamine + olanzapine (placebo on day 0 before sleep + active drug 5 mg

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1) Unresectable, advanced, or recurrent gastric or gastro-oesophageal junction cancer. 2) HER2-negative and CLDN18-positive 3) Scheduled to receive zolbetuximab plus chemotherapy (a fluoropyrimidine and oxaliplatin doublet regimen). 4) No prior administration of zolbetuximab or CLDN18.2-targeted therapeutic agents. 5) Age 18 years or older on the date of informed consent. 6) ECOG PS 0-2. 7) No severe impairment of major organs and meets laboratory criteria. 8) Prior to enrolment in this trial, the patient has received a thorough explanation of the trial content and has provided written informed consent.

Exclusion criteria

Exclusion criteria: 1) The presence of symptoms such as nausea or vomiting. 2) Presence of symptomatic brain metastases or meningeal dissemination. 3) Diabetes mellitus that contraindicates olanzapine administration. 4) Inability to take olanzapine orally. 5) Plans to take prescribed medications. 6) Presence of a psychiatric disorder that would make participation in this trial difficult. 7) Any other conditions deemed inappropriate by the attending physician.

Design outcomes

Primary

Measure	Time frame
The percentage of cases of vomiting that were controlled by the investigator's judgement throughout the entire first course.	—

Secondary

Measure	Time frame
Complete response rate, complete control rate, and total control rate during the acute phase, late phase, and entire treatment period of the first course Nausea, vomiting, and anorexia during the second and third courses Rescue therapy Maximum infusion speed of Zolbetuximab, presence or absence of infusion interruption or discontinuation, and total infusion time during courses 1-3 Adverse events Patient-reported outocome of nausea and vomiting	—

Measure

Time frame

Complete response rate, complete control rate, and total control rate during the acute phase, late phase, and entire treatment period of the first course Nausea, vomiting, and anorexia during the second and third courses Rescue therapy Maximum infusion speed of Zolbetuximab, presence or absence of infusion interruption or discontinuation, and total infusion time during courses 1-3 Adverse events Patient-reported outocome of nausea and vomiting

—

Contacts

Public ContactKoji Takeda

West Japan Oncology Group

datacenter@wjog.jp+81-6-6633-7400

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Sep 19, 2026