Sorafenib or placebo with either gemcitabine or capecitabine in patients with HER-2-negative advanced breast cancer that progressed during or after bevacizumab.
PURPOSE
We assessed adding the multikinase inhibitor sorafenib to gemcitabine or capecitabine in patients with advanced breast cancer whose disease progressed during/after bevacizumab.


EXPERIMENTAL DESIGN
This double-blind, randomized, placebo-controlled phase IIb study (ClinicalTrials.gov NCT00493636) enrolled patients with locally advanced or metastatic human epidermal growth factor receptor 2 (HER2)-negative breast cancer and prior bevacizumab treatment. Patients were randomized to chemotherapy with sorafenib (400 mg, twice daily) or matching placebo. Initially, chemotherapy was gemcitabine (1,000 mg/m(2) i.v., days 1, 8/21), but later, capecitabine (1,000 mg/m(2) orally twice daily, days 1-14/21) was allowed as an alternative. The primary endpoint was progression-free survival (PFS).


RESULTS
One hundred and sixty patients were randomized. More patients received gemcitabine (82.5%) than capecitabine (17.5%). Sorafenib plus gemcitabine/capecitabine was associated with a statistically significant prolongation in PFS versus placebo plus gemcitabine/capecitabine [3.4 vs. 2.7 months; HR = 0.65; 95% confidence interval (CI): 0.45-0.95; P = 0.02], time to progression was increased (median, 3.6 vs. 2.7 months; HR = 0.64; 95% CI: 0.44-0.93; P = 0.02), and overall response rate was 19.8% versus 12.7% (P = 0.23). Median survival was 13.4 versus 11.4 months for sorafenib versus placebo (HR = 1.01; 95% CI: 0.71-1.44; P = 0.95). Addition of sorafenib versus placebo increased grade 3/4 hand-foot skin reaction (39% vs. 5%), stomatitis (10% vs. 0%), fatigue (18% vs. 9%), and dose reductions that were more frequent (51.9% vs. 7.8%).


CONCLUSION
The addition of sorafenib to gemcitabine/capecitabine provided a clinically small but statistically significant PFS benefit in HER2-negative advanced breast cancer patients whose disease progressed during/after bevacizumab. Combination treatment was associated with manageable toxicities but frequently required dose reductions.