Phase Ii Trial Of Weekly Nab-Paclitaxel In Combination With Bevacizumab As First-Line Treatment In Metastatic Breast Cancer

1075 Background: In a clinical trial of 722 patients (pts) with locally recurrent metastatic breast cancer (MBC) solvent-based paclitaxel 90 mg/m2 was administered intravenously (IV) over 1 hr weekly for 3 weeks followed by a week of rest (q3/4w) alone or in combination with bevacizumab 10 mg/kg every 2 weeks (q2w) (Miller et al, ASCO 2005). As compared with single agent, the combination had a greater median progression-free survival (PFS; 11.4 vs. 6.11, p < 0.0001) and overall response rate (ORR; 30% vs. 14%, p < 0.0001). The purpose of the current study is to evaluate safety and tolerability and PFS, and secondarily ORR, of a solvent-free, 130- nanometer albumin bound (nab-) paclitaxel in combination with bevacizumab in MBC. Methods: In this multicenter, open-label study in the US Oncology Research Network, HER2-negative pts with MBC, receiving first line chemotherapy were given weekly nab- paclitaxel 125 mg/m2 IV infused over 30 minutes on days 1, 8, and 15, and bevacizumab 10 mg/kg on days 1 and 15 of a 28- day cycle. HER2-negative pts with measurable adenocarcinoma of the breast with ECOG PS 0–2 were included. Results: 49 women were enrolled from 19 October 2005 to 26 October 2007 with 41 pts treated (mean age, 59 years; mean # cycles, 4.0). To date 27 pts are evaluable for response. 93% of pts had visceral disease 59% had prior chemotherapy, 41% had anthracycline, 12% had docetaxel and 12% had paclitaxel in the adjuvant setting. The confirmed ORR was 30% (8/27 pts with a partial response). Stable disease>16 wks was 22% (6/27). The median PFS was 9.2 months (95% confidence interval: 5.3 - >16.1). Grade 3, 4 hematologic adverse events were neutropenia (30%, 16%) and anemia (8%, 3%). The most common nonhematologic grade 3, 4 adverse event was sensory neuropathy (10%, 2%). Conclusions: Results on this preliminary analysis shows that nab-paclitaxel in combination with bevacizumab has promising PFS and an acceptable safety profile with no unanticipated toxicities. Updated data will be presented. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Abraxis Abraxis