Trial closure: MAC25

MAC25 (NRG-BR004): A Randomized, Double-Blind, Phase III Trial of Taxane/Trastuzumab/Pertuzumab with Atezolizumab or Placebo in First-Line HER2-Positive Metastatic Breast Cancer trial has closed.

The primary objective was to determine whether the addition of atezolizumab to a regimen of pertuzumab and trastuzumab combined with a taxane will improve the PFS, assessed by investigator using RECIST 1.1 criteria, relative to a regimen of a taxane, pertuzumab, trastuzumab, and placebo in patients with newly documented HER2-positive measurable metastatic breast cancer. Secondary objectives include determining whether the addition of atezolizumab to a regimen of paclitaxel, pertuzumab, and trastuzumab will: improve the overall survival relative to a regimen of paclitaxel, pertuzumab, trastuzumab, and placebo; improve the overall objective response, assessed by investigator using RECIST 1.1 criteria, relative to a regimen of paclitaxel, pertuzumab, trastuzumab, and placebo; improve PFS, OR, and/or duration of objective response assessed by retrospective blinded central review using RECIST 1.1 criteria, relative to a regimen of paclitaxel, pertuzumab, trastuzuma and placebo.