Background: APF530 provides controlled, sustained release of granisetron for preventing acute (0-24 h) and delayed (24-120 h) CINV. In a phase 3 trial measuring complete response (CR; no emesis or rescue medication), APF530 was noninferior to PALO in preventing acute and delayed CINV in MEC pts and acute CINV in HEC pts (defined by Hesketh, J Clin Oncol. 1997). We report data from 608 breast cancer pts in this trial. Methods: Pts receiving single-dose MEC or HEC were randomized to APF530 250 or 500 mg SC (granisetron 5 or 10 mg) or PALO 0.25 mg IV prior to cycle 1 (C1). In C2-4, PALO pts were randomized to APF530 250 or 500 mg; APF530 pts continued their C1 APF530 dose. Between-group comparisons used Fisher’s exact test. Results: In C1, 78% of 423 MEC pts and 75% of 185 HEC pts received cyclophosphamide + doxorubicin or epirubicin. CRs with APF530 250 or 500 mg in C1 were not significantly different from those with PALO in preventing acute and delayed CINV with MEC or HEC (Table). There were no significant differences in within-cycle CRs between APF530 doses for acute and delayed CINV in MEC or HEC in C2-4. Both APF530 doses combined elicited high CRs during acute CINV in C2 (72%, 78%), C3 (75%, 84%), and C4 (82%, 85%) for MEC and HEC, respectively, trending toward higher CRs in later cycles. High CRs occurred in C2-4 during the delayed phase and overall risk period. Conclusions: APF530 has substantial activity in preventing CINV in first and subsequent cycles of chemotherapy in breast cancer pts receiving MEC or HEC. Clinical trial information: NCT00343460.

*P and 95% CI vs PALO.