Single-day regimen of palonosetron (PALO) and dexamethasone (DEX) for the prevention of emesis associated with moderately emetogenic chemotherapy (MEC): Subgroup analysis from a randomized phase III trial

Abstract

9620 Background: We have recently shown non-inferiority in preventing acute and delayed nausea and vomiting associated with MEC between the PALO plus 1-day DEX and PALO plus 3-day DEX regimens. Planned analysis stratified by type of chemotherapy (anthracycline + cyclophosphamide [AC] group or patients receiving at least one moderately emetogenic agent according to modified Hesketh classification) has been performed. Methods: A total of 332 chemo-naïve patients with solid tumors were randomized to receive a single IV dose of PALO 0.25 mg plus DEX 8 mg IV on day 1 of chemotherapy (arm A; n=166) or the same regimen followed by DEX 8 mg orally on days 2 and 3 (arm B; n=166). Endpoints included complete response rates (CR: no emetic episodes [EE], no rescue antiemetics; primary endpoint) and proportion of patients with no EE throughout the 5 days after the first cycle of chemotherapy. Subgroups were analyzed by two-sided chi-square test. Results: Per-protocol population included 324 patients (65% women; median age 57.5 years); 35% received AC regimens, and 65% other MEC regimens. There were no significant differences between arms in CR rates according to the type of chemotherapy: 1) CR rates on AC regimens (arm A, 55.8% versus arm B, 60.7%; p=0.599); and 2) CR rates on other MEC regimens (arm A, 68.5% versus arm B, 72%; p=0.576). No significant differences between arms were also observed in the rates of patients with no EE: 1) emesis-free patients on AC regimens (arm A, 78.8% versus arm B, 73.8%; p=0.528); 2) emesis-free patients on other MEC regimens (arm A, 83.8% versus arm B, 90%; p=0.184); 3) nausea-free patients on AC regimens (arm A, 38.5% versus arm B, 44.3%; p=0.533); and 4) nausea-free patients on other MEC regimens (arm A, 58.6% versus arm B, 64%; p=0.418). Conclusions: The single-day regimen of PALO and DEX can provide effective protection against acute and delayed emesis from AC- and MEC-based regimens while avoiding to unnecessarily prolong treatment with DEX. No significant financial relationships to disclose.