Neratinib for 12 months significantly improved 2-year invasive disease-free survival (DFS) when given after chemotherapy and trastuzumab-based adjuvant therapy to women with HER2-positive breast cancer. This according to a study of 2,480 women with HER2-positive breast cancer randomly assigned 1:1 to either neratinib or placebo. Researchers found:

• At 2-year follow-up, 70 invasive DFS events had with neratinib vs 109 events with placebo.

• 2-year invasive DFS rate was 93.9% with neratinib vs 91.6% with placebo.

• Most common grade 3 or 4 adverse events were diarrhea (40% with neratinib vs 2% with placebo); vomiting (3% vs < 1%); and nausea (2% vs < 1%).

• QT prolongation occurred in 3% of patients with neratinib vs 7% with placebo.

• Decreases in left ventricular ejection fraction (≥ grade 2) occurred in 1% of patients in both groups.

• Serious adverse events were seen in 7% of patients with neratinib vs 6% with placebo.

Citation: Chan A, Delaloge S, Holmes FA, et al. Neratinib after trastuzumab-based adjuvant therapy in patients with HER2-positive breast cancer (ExteNET): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial. [Published online ahead of print February 10, 2016]. Lancet Oncol. doi: 10.1016/S1470-2045(15)00551-3.