Neratinib given as 1-year extended adjuvant therapy significantly reduced the rate of relapse among patients with breast cancer treated with chemotherapy and trastuzumab, according to a study published in Lancet Oncology.
A previous 2-year analysis of the ExteNET phase 3 study demonstrated that extended adjuvant treatment with 1 year of neratinib — compared with placebo — significantly improved the rate of 2-year invasive disease-free survival among 2840 women who had completed neoadjuvant and adjuvant chemotherapy plus trastuzumab.
After a median follow-up of 5.2 years, patients who received neratinib vs placebo (116 vs 163, respectively) experienced significantly fewer incidences of invasive disease-free survival events (stratified hazard ratio [HR], 0.73; 95% CI, 0.57-0.92; P =.0083). The 5-year invasive disease-free survival was 90.2% (95% CI, 88.3-91.8) and 87.7% (95% CI, 85.7-89.4) in the neratinib group and placebo group, respectively.
The most frequently reported grade 3 to 4 adverse events (AEs) were diarrhea, vomiting, and nausea. Treatment-emergent serious AEs occurred in 7% of women in the neratinib and group and 6% of women in the placebo arms. There was no evidence for increased risk of long-term toxicity or consequence associated with neratinib-correlated diarrhea compared with placebo.
The authors concluded “[e]xtended adjuvant neratinib after chemotherapy and trastuzumab should be considered a new therapeutic option for this patient population,” and added that an overall survival analysis will be conducted after 248 events.
- Martin M, Holmes FA, Ejlertsen B, et al. Neratinib after trastuzumab-based adjuvant therapy in HER2-positive breast cancer (ExteNET): 5-year analysis of a randomised, double-blind, placebo-controlled, phase 3 trial [published online November 13, 2017]. Lancet Oncol. doi: 10.1016/S1470-2045(17)30717-9