Sorooshian, H., & Vo, L. (2015). A modified olanzapine regimen for the prevention of chemotherapy-induced nausea and vomiting. The Journal of Community and Supportive Oncology, 13, 388–391. 

To compare regimens using fosaprepitant and olanzapine for chemotherapy-induced nausea and vomiting (CINV) prevention

Patients on regimens for the prevention of CINV who were receiving highly emetogenic chemotherapy (HEC) received either a medication regimen of fosaprepitant, ondansetron, and dexamethasone, or a regimen of olanzapine, ondansetron, and dexamethasone. Those on the olanzapine regimen only received dexamethasone on day 1. Both groups had additional rescue medication as needed. All patients were assessed within 24–72 hours for CINV via follow-up phone calls, with results documented in the electronic medical record.

• N = 148
• MEAN AGE = 58.47 years
• AGE RANGE = 21–81 years
• MALES: 53%, FEMALES: 47%
• CURRENT TREATMENT: Chemotherapy, combination radiation and chemotherapy
• KEY DISEASE CHARACTERISTICS: All were receiving HEC. Tumor types were not reported.
• OTHER KEY SAMPLE CHARACTERISTICS: Of the patients, 38.5% were also receiving radiation therapy.

• SITE: Multi-site
• SETTING TYPE: Not specified
• LOCATION: California

• PHASE OF CARE: Active antitumor treatment

• Retrospective cohort noninferiority design

Complete response defined as no emesis after cycle 1. A difference of 15% complete response (CR) rate was used as the limit for noninferiority testing.

The difference in the CR rate between groups was 8.9% in the acute phase, 12.9% in the delayed phase, and 8.6% overall. Statistical analysis showed that results in the olanzapine group were not inferior based on the difference level specified. Comparison of wholesale acquisition costs showed that the olanzapine regimen was less than 4% of the cost of the regimen using fosaprepitant ($8.58 versus $265.59).

The olanzapine regimen tested here was associated with less than a 15% difference in CR rate compared to a regimen containing fosaprepitant.

• Risk of bias (no blinding)
• Risk of bias (no random assignment)
• Measurement validity/reliability questionable
• How CINV was assessed and documented is not described.
• No subgroup analysis for those receiving concomitant radiation therapy
• No information is provided regarding the use of breakthrough medication and any associated costs.
• No information regarding nausea severity

This study showed that a regimen based on olanzapine was not inferior to one with fosaprepitant among patients receiving HEC if a less than 15% difference in CR rate is clinically acceptable. Individuals on the olanzapine had a higher prevalence of delayed phase CINV, though those in the olanzapine regimen also did not receive dexamethasone after day 1. The fosaprepitant regimen was much more expensive than the olanzapine regimen, so it may be a good alternative for patients with limited coverage or financial resources. Additional studies are needed to identify the most cost-effective regimens for CINV prevention, and this work needs to also provide greater focus on the prevention of nausea.