The current role of bevacizumab as a treatment for patients with breast cancer is unclear, with research interests shifting toward other angiogenesis inhibitors, suggests Richard Finn, MD. The unclear role of bevacizumab was further confounded by results from the IMELDA and TANIA studies, which examined the role of bevacizumab in the treatment of breast cancer in the maintenance setting.

In the IMELDA trial, individuals with HER2-negative breast cancer were administered docetaxel and bevacizumab every 3 weeks for at least 6 cycles. Half of the study participants were then randomized to receive capecitabine with bevacizumab maintenance, or bevacizumab only. Individuals who continued capecitabine and bevacizumab demonstrated an overall survival of 40 months versus 24 months. However, one limitation of this study was the lack of non-bevacizumab arm (Gligorov J, et al. Lancet Oncol. 2014;15(12):1351-1360).

The TANIA trial looked at patients with HER2-negative locally recurrent or metastatic breast cancer that had progressed after receiving 12 weeks or more of first-line bevacizumab plus chemotherapy. Patients were randomized to receive chemotherapy alone or chemotherapy plus bevacizumab. At the time of progression, patients in the chemotherapy-alone arm received third-line chemotherapy; patients in the bevacizumab arm continued on bevacizumab plus third-line chemotherapy.

Progression-free survival was significantly longer for patients treated with bevacizumab plus chemotherapy compared with chemotherapy alone (median: 6.3 months vs 4.2 months, P = .0068), demonstrating that maintenance bevacizumab could be a viable option for some patients (von Minckwitz G, et al. Lancet Oncol. 2014;15(11):1269-1278).

Findings from these studies suggest a potential sub-population benefit from bevacizumab therapy, Lee Schwartzberg, MD, comments. However, without a biomarker for bevacizumab, it still remains unclear which patients will benefit from the treatment.