Olanzapine Dose Comparison for the Prevention of HER-INV: A Network Meta-Analysis

Olanzapine 2.5 mg Versus 5 mg Versus 10 mg in Highly Emetogenic Regimens: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials.

Olanzapine is an effective antiemetic agent for preventing highly emetogenic regimens-induced nausea and vomiting (HER-INV) in patients receiving highly emetogenic regimens (HER). The optimal dose remains debated, with the standard 10 mg dose often causing significant daytime sedation. Recent evidence suggests that lower doses (2.5 mg and 5 mg) may offer comparable efficacy with improved tolerability. However, no head-to-head randomized controlled trials (RCTs) directly compare all three doses.

Study Overview

• Status: Completed
• Conditions: Solid Tumours; Nausea and Vomiting; Olanzapine
• Intervention / Treatment: Drug: Olanzapine (dose comparison: 2.5 mg, 5 mg, 10 mg)

Detailed Description

To compare the relative efficacy and safety of olanzapine at 2.5 mg, 5 mg, and 10 mg, in combination with standard triple antiemetic prophylaxis, for the prevention of HER-INV in adult patients undergoing HER, using a network meta-analysis (NMA) of RCTs. RCTs comparing any two doses of olanzapine (2.5 mg, 5 mg, 10 mg) in adults with solid tumors.

Inclusion Criteria:

1. Olanzapine was used to prevent nausea and vomiting (HER-INV) in solid tumors patients receiving highly emetogenic regimens
2. Randomized controlled trials (RCTs), including conference abstracts if sufficient data are provided.
3. Adult patients (≥18 years) with solid tumors receiving highly emetogenic chemotherapy (HEC).

3. Olanzapine at 2.5 mg, 5 mg, or 10 mg, added to a standard triple antiemetic regimen (NK1 receptor antagonist + 5-HT3 receptor antagonist + dexamethasone).

4. Any of the other three olanzapine doses or placebo (2.5 mg vs. 5 mg vs. 10 mg, or vs. placebo).

5. At least one of the pre-specified efficacy or safety outcomes must be reported.

Exclusion Criteria:

1. Non-solid tumors patients, non-randomized studies, observational studies, case reports, reviews.
2. Studies involving pediatric populations, non-HEC regimens.
3. Studies where olanzapine is used as rescue medication only.
4. Studies with overlapping patient populations (the most recent or complete publication will be selected).

Information Sources: Electronic databases: PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science Core Collection. We will also search clinical trial registries (ClinicalTrials.gov, WHO ICTRP) and manually review reference lists of relevant systematic reviews and included studies.

Risk of Bias Assessment: The risk of bias for individual RCTs will be assessed using the revised Cochrane Risk of Bias tool for randomized trials (RoB 2.0) by two independent reviewers.

Subgroup Analyses: Subgroup analyses are planned by treatment regimens (such as: cisplatin-based vs. AC-based et al.).

• Study Type: Observational
• Enrollment (Actual): 2000

Contacts and Locations

Study Locations

• China
  • Shandong
    • Jinan, Shandong, China
      • Department of Medical Oncology

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

All patients with solid tumors received different doses of olanzapine (2.5 mg, 5 mg, 10 mg) as an add-on to standard antiemetic prophylaxis for the prevention of HER-induced nausea and vomiting in adult (≥18 years) patients with solid tumors receiving highly emetogenic regimens.

Description

Inclusion Criteria:

1. Olanzapine was used to prevent nausea and vomiting (HER-INV) in solid tumors patients receiving highly emetogenic regimens.
2. Randomized controlled trials (RCTs), including conference abstracts if sufficient data are provided.
3. Adult patients (≥18 years) with solid tumors receiving highly emetogenic chemotherapy (HEC).

3. Olanzapine at 2.5 mg, 5 mg, or 10 mg, added to a standard triple antiemetic regimen (NK1 receptor antagonist + 5-HT3 receptor antagonist + dexamethasone).

4. Any of the other three olanzapine doses or placebo (2.5 mg vs. 5 mg vs. 10 mg, or vs. placebo).

5. At least one of the pre-specified efficacy or safety outcomes must be reported.

Exclusion Criteria:

1. Non-solid tumors patients, non-randomized studies, observational studies, case reports, reviews.
2. Studies involving pediatric populations, non-HEC regimens.
3. Studies where olanzapine is used as rescue medication only. Studies with overlapping patient populations (the most recent or complete publication will be selected).

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Olanzapine Doses 2.5mg	Drug: Olanzapine (dose comparison: 2.5 mg, 5 mg, 10 mg); Olanzapine (dose: 2.5 mg) vs. olanzapine (dose: 5 mg) vs. olanzapine (dose: 10 mg)
Olanzapine Doses 5mg	Drug: Olanzapine (dose comparison: 2.5 mg, 5 mg, 10 mg); Olanzapine (dose: 2.5 mg) vs. olanzapine (dose: 5 mg) vs. olanzapine (dose: 10 mg)
Olanzapine Doses 10mg	Drug: Olanzapine (dose comparison: 2.5 mg, 5 mg, 10 mg); Olanzapine (dose: 2.5 mg) vs. olanzapine (dose: 5 mg) vs. olanzapine (dose: 10 mg)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The complete response rate of nausea and vomiting in the overall phase (including acuted and delayed phase) by highly emetogenic regimens in solid tummors.	Nausea and vomiting complete response (CR; no vomiting or retching, no rescue medication) rate in the overall phase (including acuted [0-24h] and delayed [>24h] phase ) after highly emetogenic regimens in solid tummors .	Nausea and vomiting complete response was assesed during the treatment period (or during the overall assessment period) after the initiation of highly emetogenic regimens, up to 4 weeks.

Collaborators and Investigators

• Sponsor: Shandong Cancer Hospital and Institute

Study record dates

Study Major Dates

• Study Start (Actual): January 18, 2026
• Primary Completion (Actual): February 15, 2026
• Study Completion (Actual): March 30, 2026

Study Registration Dates

• First Submitted: January 18, 2026
• First Submitted That Met QC Criteria: February 10, 2026
• First Posted (Actual): February 11, 2026

Study Record Updates

• Last Update Posted (Actual): May 19, 2026
• Last Update Submitted That Met QC Criteria: May 16, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Olanzapine; Solid tumours; Nausea and Vomiting; Network Meta-Analysis; High emetic risk
• Additional Relevant MeSH Terms: Signs and Symptoms, Digestive; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Nausea; Vomiting; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Benzazepines; Benzodiazepines; Olanzapine
• Other Study ID Numbers: SDTHEC-IF

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No