Avastin for the bust.
The Study: The phase 3 E5103 trial questioned the benefit of the addition of bevacizumab (aka Avastin) in women with a high risk of HER2(-) breast cancer recurrence. Such high risk features included node positivity, estrogen receptor (ER) negativity, a tumor > 5 cm, or a tumor > 2 cm with an Oncotype DX ≥ 11. A whopping 5K women were enrolled following treatment with surgery alone and randomized to one of three adjuvant treatments:  standard doxorubicin / cyclophosphamide → paclitaxel (ACT),  AC + bev → T,  ACT with bev throughout and after. The primary endpoint of disease-free survival (DFS) at 5 years was pretty much the same in all arms at rates of 76-80%. Rates of overall survival at 5 years were similarly similar at 86-90%. This may be because almost a quarter of arm 2 and more than half of arm 3 discontinued therapy early due to side effects, particularly hypertension. The authors have two main conclusions. First, there’s nothing to see here but extra toxicity. Second, and more broadly speaking, the E5 trials highlight the role of publicly (read: not industry) sponsored trials in serving more than a financial agenda. In other words, the authors used their extra time (and 1K words in the discussion) on interesting unrelated secondary analyses rather than on obscuring an undoubtedly negative primary endpoint.
Bottom Line: Indications for bevacizumab are few and far between, and adjuvant therapy for HER2(-) breast cancer falls in between. | Miller, J Clin Oncol 2018