In a multicenter, randomized, stratified, double-blind, parallel-group, clinical trial, palonosetron hydrochloride injection was compared to placebo for PONV in 546 patients undergoing abdominal and gynecological surgery. All patients received general anesthesia. The trial was conducted predominantly in the US in the out-patient setting for patients undergoing elective gynecologic or abdominal laparoscopic surgery and stratified at randomization for the following risk factors: gender, non-smoking status, history of PONV and/or motion sickness.
Patients were randomized to receive a single dose of palonosetron hydrochloride injection 0.025 mg, 0.050 mg or 0.075 mg or placebo, each given intravenously immediately prior to induction of anesthesia. Antiemetic activity of was evaluated during the 0 to 72-hour time period after surgery.
Of the 138 patients treated with palonosetron hydrochloride injection 0.075 mg and evaluated for efficacy, 96% were women; 66% had a history of PONV or motion sickness; 85% were non-smokers. As for race, 63% were White, 20% were Black, 15% were Hispanic, and 1% were Asian. The age of patients ranged from 21 to 74 years, with a mean age of 38 years. Three patients were greater than 65 years of age.
Co-primary efficacy measures were Complete Response (CR) defined as no emetic episode and no use of rescue medication in 0 to 24 hours and 24 to 72 hours postoperatively.
Secondary efficacy endpoints included:
- Complete Response (CR) 0 to 48 hours and 0 to 72 hours
- Complete Control (CC) defined as CR and no more than mild nausea
- Severity of nausea (none, mild, moderate, severe)
The primary hypothesis was that at least one of the three palonosetron doses were superior to placebo.
Complete Response Rates for palonosetron hydrochloride injection 0.075 mg and placebo in this trial are described in the Table 9.
Table 9: Prevention of Postoperative Nausea and Vomiting in Adults: Complete Response Rates
|
|
| Treatment | n/N (%) | Palonosetron hydrochloride injection vs Placebo |
| Δ | p-value
a |
| Co-primary Endpoints |
| Complete Response Rate (0 to 24 hours) |
| Palonosetron hydrochloride injection 0.075 mg intravenously | 59/138 (42.8%)
| 16.8%
| 0.004
|
| Placebo | 35/135 (25.9%)
| |
| Complete Response Rate (24 to 72 hours) |
| Palonosetron hydrochloride injection 0.075 mg intravenously | 67/138 (48.6%)
| 7.8%
| 0.188
|
| Placebo | 55/135 (40.7%)
| |
Palonosetron hydrochloride injection as a single dose of 0.075 mg reduced the severity of nausea compared to placebo. Analyses of other secondary endpoints indicate that palonosetron hydrochloride injection 0.075 mg was numerically better than placebo, however, statistical significance was not formally demonstrated.
A randomized, double-blind, multicenter, placebo-controlled, dose ranging study was performed to evaluate palonosetron hydrochloride injection for PONV following abdominal or vaginal hysterectomy. Five intravenous doses (0.1, 0.3, 1.0, 3.0 and 30 mcg/kg) were evaluated in a total of 381 intent-to-treat patients. The primary efficacy measure was the proportion of patients with CR in the first 24 hours after recovery from surgery. The lowest effective dose was palonosetron hydrochloride injection 1 mcg/kg (approximately 0.075 mg) which had a CR rate of 44% versus 19% for placebo, p=0.004 and significantly reduced the severity of nausea versus placebo, p=0.009.