ERBB2 and breast cancer: In the adjuvant setting, neratinib has recently been approved by the FDA for extended treatment of early-stage HER2-positive BC [89], based on the results of the phase III ExteNEt trial, which reported a small but significant improvement in 2-year DFS in women who received it after adjuvant trastuzumab versus placebo (93.9% versus 91.6%, HR = 0.67, 95% CI: 0.50–0.91, p = 0.0091) [90].