Palonosetron versus other 5-HT(3) receptor antagonists for prevention of chemotherapy-induced nausea and vomiting in patients with cancer on chemotherapy in a hospital outpatient setting.

Background: Despite favorable evidence from clinical trials for single-dose palonosetron versus other commercially available 5-HT(3)-receptor antagonists for the prophylaxis of chemotherapy-induced nausea and vomiting (CINV), clinical comparative data are scarce from hospital outpatient settings, where these antiemetic agents are used in patients diagnosed with cancer who are receiving chemotherapy (CTH).

Objective: The purpose of our retrospective study was to assess the hospital claims to evaluate the rate of uncontrolled CINV with antiemetic prophylaxis using palonosetron versus other 5-HT(3)-receptor antagonists in patients diagnosed with cancer who are receiving CTH (highly emetogenic CTH, moderately emetogenic CTH, low-emetogenic CTH, or minimally emetogenic CTH) treatment in a hospital outpatient setting.

Methods: Patients aged ≥18 years who had cancer and were being treated with CTH and antiemetic prophylaxis with palonosetron (Group 1) and other 5-HT(3) receptor antagonists (Group 2) for the first time between April 1, 2007, and March 31, 2009, were identified using a hospital-service database. Within each CTH cycle, CINV events were identified through International Classification of Diseases (ICD)-9 codes for nausea, vomiting, and/or volume depletion (from Day 1 of each CTH administration until the end of the CTH cycle) or for use of rescue medications (Day 2 until the end of the CTH cycle). A multivariate regression model was developed to predict uncontrolled CINV event rates per CTH cycle between Groups 1 and 2 matched on CTH emetogenicity distribution in the study follow-up period (first of 8 cycles or 6 months). A subgroup analysis of patients on CTH with the highest risk of nausea and vomiting (highly emetogenic CTH or moderately emetogenic CTH) was also conducted.

Results: Of 9144 identified patients, 1775 were prescribed palonosetron (Group 1). Group 1 patients were statistically younger (61.2 vs 62.8 years; P < 0.001), composed of more females (57.1% vs 51.9%; P < 0.001) and more whites (72.8% vs 71.4%; all races P < 0.001), received more highly emetogenic CTH treatments (43.3% vs 28.5%; all CTH P < 0.001), and had more lung (26.1% vs 22.4%) and breast cancer patients (19.3% vs 15.3%; all cancer P < 0.001). The regression model predicted a 13.7% decrease in CINV event rate per CTH cycle for Group 1 versus Group 2. For Subgroup 1, the model predicted a 12.5% decrease in the CINV event rate per cycle in Group 1 patients versus those in Group 2.

Conclusions: In this study, patients with cancer who were treated with CTH and on antiemetic prophylaxis using palonosetron were found to have significantly lower CINV event rates than those receiving other 5-HT(3) receptor antagonists.