Efficacy and safety of a combination of HER2-targeted agents as first-line treatment for metastatic HER2-positive breast cancer: a network meta-analysis.

BACKGROUND: Using network meta-analysis, we assessed the efficacy and safety of a combination regimen of HER2-targeted agents as first-line treatment for metastatic HER2-positive breast cancer.

METHODS: We searched the Medline, Embase, and Cochrane Library electronic databases (through December 2016) for phase II/III randomized controlled trials that compared regimens of one or two HER2-targeted agents combined with trastuzumab or chemotherapy. A network meta-analysis including direct and indirect analyses was conducted in WinBUGS using fixed and random effects. Study quality was assessed following the Grading of Recommendations, Assessment, Development and Evaluations method. The primary outcome was overall survival.

RESULTS: The network meta-analysis incorporated nine HER2-targeted regimens with 9 direct comparisons and 28 indirect comparisons for the main outcomes (8 studies; n = 3976). Combining direct and indirect effects showed significant increased efficacy of trastuzumab and docetaxel plus pertuzumab (TDP) over other regimens as first-line treatment. With indirect comparison of overall safety, TDP, TDM-1, and TDM-1 plus pertuzumab demonstrated a lower risk of grade 3-4 adverse events compared to other regimens.

CONCLUSIONS: TDPs are a preferred first-line treatment for HER2-positive metastatic breast cancer compared with other target agent regimens.