Randomized phase II study comparing efficacy and safety of combination-therapy trastuzumab and docetaxel vs. sequential therapy of trastuzumab followed by docetaxel alone at progression as first-line chemotherapy in patients with HER2+ metastatic breast cancer: HERTAX trial.

Abstract Background Because chemotherapy for metastatic breast cancer (MBC) is associated with relevant toxicity, sequential monotherapy trastuzumab followed by cytotoxic therapy at disease progression might be an attractive approach. Methods In a multicenter phase II trial, 101 patients with overexpression of human epidermal growth factor receptor 2 (HER2 + ) MBC were randomized between combination-therapy trastuzumab (Herceptin) plus docetaxel (H+D) and sequential therapy of single-agent trastuzumab followed at disease progression by docetaxel alone (H→D) as first-line chemotherapy for metastatic disease. The primary endpoint was progression-free survival (PFS) after completed sequential or combination therapy. Results For the H+D group the median PFS was 9.4 vs. 9.9 months for the H→D group and 1-year PFS rates were 44% vs. 35%, respectively. However the overall response rates (ORRs) were 79% vs. 53%, respectively ( P = .016), and overall survival was 30.5 vs. 19.7 months, respectively ( P = .11). In the H→D group, response rates to monotherapy trastuzumab and subsequent docetaxel were 34% and 39%, respectively, with a median PFS during single-agent trastuzumab of 3.9 months. The incidence and severity of neuropathy were significantly higher in the H+D group. Retrospective analysis of trastuzumab treatment beyond progression (applied in 46% of patients in the H+D group and 37% in the H→D group) showed a correlation with longer overall survival in both treatment arms (36.0 vs. 18.0 months and 30.3 vs. 18.6 months, respectively). Conclusion First-line treatment in patients with MBC with H→D resulted in a similar PFS compared with H+D, but the response rate was lower and the overall survival nonsignificantly shorter.