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 100mg/m2, B 10mg/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.