Chemotherapy Plus Bevacizumab Promising in Advanced TNBC

A triplet regimen including paclitaxel, capecitabine, and bevacizumab, followed by maintenance therapy with the latter two agents, showed high activity and a reasonable safety profile in women with triple-negative, locally advanced/metastatic breast cancer, according to a new study.

“For patients with estrogen receptor–negative, progesterone receptor–negative, and HER2-negative metastatic breast cancer…there are, to the best of our knowledge, currently no receptor-targeted treatment options and the prognosis for patients is poor compared with that for individuals with receptor-positive disease,” wrote study authors led by Jean-Marc Ferrero, MD, PhD, of the Antoine-Lacassagne Centre in Nice, France.

Previous work has suggested that combining bevacizumab with chemotherapy could provide benefit in triple-negative patients. The new A-TaXel phase II study included 62 patients enrolled between April 2010 and March 2012, 57 of whom were evaluable for safety and efficacy. Patients received 4 weekly cycles of paclitaxel combined with capecitabine and bevacizumab; the paclitaxel was stopped after a maximum of 6 cycles, and the other two drugs continued until disease progression or unacceptable toxicity. The results were published in Cancer.

The overall response rate (ORR) was 77%, and 19% of patients had a complete response; this met the primary objective of the study. Another 14% had stable disease, yielding a clinical benefit rate of 91%. Among the 44 patients who responded, the median duration of response was 5.6 months.

At the time of data cutoff, 56 of the 62 initially enrolled patients had progressed or died. The median progression-free survival was 7.6 months, and the median overall survival was 19.2 months. At 1 year, the overall survival rate was 69%.

The most common adverse events included fatigue in 90% of patients, pain in 84%, and hypertension in 79%. For adverse events grade 3 or higher, the most common included hypertension (35%), fatigue (19%), and hand-foot syndrome (13%). With regard to hematologic events, the most common grade 3 or higher events included neutropenia (23%) and thrombocytopenia (16%).

In total, 18% of patients discontinued paclitaxel due to toxicity; 15% discontinued capecitabine, and 25% discontinued bevacizumab. Bevacizumab treatment was interrupted in 47% of patients, most often due to infection or hypertension.

The authors noted that the response rate seen with this regimen was “among the highest observed” in this difficult disease setting. “It is important to note that the high ORR observed in the current study was achieved with acceptable tolerability,” they wrote.