Bevacizumab and albumin-bound paclitaxel treatment in metastatic breast cancer

Abstract

1101 Background: Miller, et al demonstrated the combination of bevacizumab and paclitaxel has significant activity in metastatic breast cancer. Because paclitaxel albumin bound (PAB) has been shown to have less toxicity, a better tumor delivery and possibly better response for metastatic breast cancer, we combined it with bevacizumab (B) to treat women with metastatic breast cancer. Methods: This is a retrospective analysis. Billing records from March 2005 through December 2006 were reviewed to obtain all patients treated consecutively with a combination of PAB (80–125mg/m2 days 1,8,15 or 170–200 mg/m2 every 14 days on a 28 day cycle) and B (10mg/kg every 14 days). A total of 40 women were identified. A minimum of two courses were given. All women had received a minimum of 3 prior chemotherapy regimens including anthracyclines 34/40 and taxanes 35/40. Patients were monitored for response using RECIST criteria based on PE, and PET/CT imaging. Six women with bone only disease were monitored with PET, CT/MRI and tumor markers. All response data were confirmed by independent review. Results: 20 women had objective responses to the PAB/B regimen (3CRs and 17PRs) for an overall response rate of 50%. Another seven women had stable disease (SD) for a mean duration of 212 days. Thirteen women progressed. The mean time to progression for the responders was 132 days. Toxicity was acceptable with fatigue (9 gr 2), neuropathy (4 gr 2, 1 gr 3), anemia (2 gr 2, 2 gr 3), and hypertension (3 gr 2) being the most common complaints. Two patients were discontinued due to a possible CNS hemorrhage into a metastatic brain lesion. There were no other treatment discontinuations due to non-tolerance Conclusions: In our limited series of consecutive woman with advanced, heavily pretreated metastatic breast cancer treated with PAB (Abraxane) and bevacizumab (Avastin), we saw a 50% objective response rate (3CR, 17PR). The regimen was well tolerated with acceptable toxicity. Another seven women had stable disease for an average duration of >200days giving an objective response rate + SD of 67%. No significant financial relationships to disclose.