Background: Irinotecan and bevacizumab have single agent activity in platinum sensitive (PSen) and resistant (PRes) ovarian cancer patients (pts). We sought to evaluate the efficacy and toxicity of irinotecan plus bevacizumab in these pts. The trial was designed to evaluate whether the progression free survival (PFS) at 6 months is at least 40% and with secondary objectives of estimating response rate (RR), duration of response (DoR), time to progression and toxicity. Methods: No limitation on number of prior regimens was placed, and prior use of study drugs was allowed. Irinotecan 250mg/m2 and bevacizumab 15mg/kg every 3 weeks were given. Due to treatment-related grade 3 toxicity (diarrhea and neutropenia) experienced by the first 5 pts on the study, the dose of irinotecan was amended to 175mg/m2. Results: 20 pts with recurrent ovarian cancer [PSen 5, PRes 15] of a planned 35 have been recruited thus far. Median age is 59 (45-78). Median number of prior regimens is 5 (3-12) with 9 pts demonstrating progressive disease (PD) on prior topotecan-containing regimens and 7 pts exhibiting PD on prior bevacizumab-containing regimens. 4 pts discontinued treatment before 2 cycles (2 for protocol defined toxicity, 2 by patient/physician choice). Partial response (PR) was observed in 2 PSen pts and 1 PRes pt, while stable disease (SD)was seen in 9 (2 PSen, 7 PRes) out of the 15 pts assessable for response at this time. 3 pts demonstrated PD after 2 cycles of treatment. 12 of 13 pts with PR or SD by RECIST also had response by CA125 criteria. Median DoR thus far (SD plus PR) is 18 weeks (4-37). 6 pts have ongoing response (4-18 weeks). Of 19 pts that received > 2 cycles, 3 had grade 3 diarrhea (2 before protocol amendment and 1 after). 2 pts had grade 3/4 neutropenia (1 before and 1 after protocol amendment). Median PFS is 9.6 months (mts). Median overall survival is 15.5 mts. PFS rate at 6 mts is 61% with 95% confidence interval: (40%, 92%). Conclusions: Results of the trial to date suggest the hypothesis that the PFS at 6 mts is less than 40% can be rejected. Activity of this regimen is encouraging given the heavily pretreated nature of the pts. Dose-limiting diarrhea and neutropenia required protocol amendment. We continue to accrue study subjects at the amended dosing.