Abstract 1673P
Background
Carboplatin (CBDCA) is classified as a moderate emetic risk but is a higher risk than other chemotherapy agents. Therefore, a three-drug prophylactic antiemetic regimen is recommended comprising a 5-hydroxytryptamine type-3 receptor antagonist (5-HT3 RA), dexamethasone, and a neurokinin-1 receptor antagonist (NK1 RA). Olanzapine (OLZ) is lower cost than NK1 RA and more effective in controlling nausea. This phase II study aimed to investigate the efficacy and safety of a low dose of 5 mg OLZ in combination with 5-HT3 RA and dexamethasone for CBDCA-induced nausea and vomiting in patients with thoracic malignancies.
Methods
Patients who received an area under the curve (AUC) ≥5 mg/mL/min of CBDCA-based regimen were eligible. All patients received OLZ (5 mg/day on days 1–4) in combination with granisetron and dexamethasone. The primary endpoint was complete response (CR: no emesis and no use of rescue medication) rate during the overall assessment period (0–120 h) after initiation of CBDCA. Complete control (CC) rate and total control (TC) rate were secondary endpoints. Given the null hypothesis of a CR rate ≤65% and an alternative hypothesis of 80%, a minimum of 48 patients was required to achieve a one-sided type I error of 0.1 and 80% power.
Results
The 50 patients who met the criteria were evaluated in the efficacy and safety analysis. The CR rate in the overall phase was 94.0% (80% confidence interval, 87.1–97.8, P < 0.0001). The CR rate, CC rate, and TC rate in the acute (0–24 h) phase were all 100.0%. The TC rate in the delayed phase (24–120 h) was 86.0%. No grade ≥3 adverse events of OLZ were observed. Table: 1673P
| Overall phase | Acute phase | Delayed phase | ||||||
| No. | (%) | 80% C. I. | p value | No. | (%) | No. | (%) | |
| Complete response | 47 | 94.0 | (87.1–97.8) | <0.0001 | 50 | 100.0 | 47 | 94.0 |
| Complete control | 47 | 94.0 | 50 | 100.0 | 47 | 94.0 | ||
| Total control | 43 | 86.0 | 50 | 100.0 | 43 | 86.0 |
Conclusions
A low dose of 5 mg OLZ plus granisetron and dexamethasone appears to be a reasonable treatment approach in patients with thoracic malignancies receiving a CBDCA (AUC ≥ 5)-based regimen.
Clinical trial identification
Editorial acknowledgement
We would like to thank Cambridge English Correction Service for the English language editing.
Legal entity responsible for the study
H. Iihara.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.