Paclitaxel albumin-bound particles (abraxane™) in combination with bevacizumab with or without gemcitabine: Early experience at the University of Miami/Braman Family Breast Cancer Institute

Background: Paclitaxel albumin-bound particles (nab-paclitaxel, ABRAXANE™) (nab-P) improve outcomes when compared against single agent cremophor-based paclitaxel, as do the addition of bevacizumab (B) or gemcitabine (G) to the same agent. There are no available data regarding combinations of nab-P with B and/or G. Ongoing investigational efforts are evaluating various doublets with these agents, but, to the best of our knowledge, not all 3 of them in the same regimen. All drugs are currently FDA-approved in the treatment of cancer. Methods: Review of single-institution experience, evaluating safety and preliminary evidence of activity with the use of nab-P and B with and without G in heavily pretreated her2neu-negative metastatic breast cancer patients. Assessment of response was undertaken by the investigators independently of treating physician. RECIST criteria were used. Results: Six women have been evaluated. Three patients received nab-P and B at the following doses: nab-P 100 mg/m², B 10 mg/kg and 3 patients also received G at 1000 mg/m²; all 3 drugs were given every 2 weeks. Median age was 51 (range, 34-69). Two patients had hormone-receptor positive disease and 3 had ER/PR/her2neu-negative cancer. Median prior number of regimens was 3 (range, 2-7). Five patients had been previously treated with a taxane. One received both paclitaxel and docetaxel, and 4 received docetaxel only. A median of 16 weeks of treatment has been administered (range 8+-32+). First-cycle grade 3/4 toxicity was seen in only one patient who had a baseline grade 2 thrombocytopenia that progressed to grade 3. The thrombocytopenia resolved without transfusion or hemorrhagic complication. Other treatment related toxicities were as follows: grade 2 peripheral neuropathy, 1 patient; grade 2 nausea, 1 patient. One patient had a blood pressure of 210/140 mmHg while non-compliant with her prior anti-hypertensive therapy. Two patients had confirmed partial responses and 4 patients had stable disease. Conclusion: These very preliminary data suggest that nab-P in combination with B with and without G is a safe regimen and a formal phase II trial has been developed at the University of Miami to confirm its safety and clinical activity.