Double-blind, randomised, controlled study of the efficacy and tolerability of palonosetron plus dexamethasone for 1 day with or without dexamethasone on days 2 and 3 in the prevention of nausea and vomiting induced by moderately emetogenic chemotherapy.

Background: To reduce side-effects of corticosteroid-containing antiemetic regimens, tailoring antiemetic schedules to specific requirements of different patients could be of benefit. We evaluated the possibility to reduce the total dose of corticosteroids when palonosetron, a long-acting second-generation 5-hydroxytryptamine-3 (5-HT(3)) receptor antagonist, is used.
Materials and Methods: Double-blind, multicentre, noninferiority study of chemotherapy-naive breast cancer patients receiving 0.25 mg palonosetron and 8 mg dexamethasone on day 1, randomly assigned to receive placebo (n = 151) or 4 mg b.i.d. dexamethasone (n = 149) on days 2 and 3. Primary end point was complete response (CR) rate (no emesis, no rescue medication) in the overall (days 1-5) period. Secondary end points were CR rates in the acute (day 1) and delayed (days 2-5) periods, rates of no emesis and no nausea and impact on daily functioning (Functional Living Index-Emesis).
Results: Noninferiority between the two treatments was demonstrated by similar CR rates (P = 0.487) in the overall period. Most parameters showed that palonosetron and dexamethasone on day 1 only offer chemotherapy-induced nausea and vomiting protection similar to multiple-day dexamethasone administration.
Conclusion: In patients treated with a single injection of palonosetron on day 1, reducing dexamethasone is an option that is not associated with significant reduction in antiemetic control during the 5-day period or an impact on patient functioning.