ERBB2 and Decreased total leukocyte count: Upon cessation of chemotherapy, when patients received HER2-targeted therapy only, the incidence of adverse events of interest to pertuzumab treatment declined: leukopenia was reported in 88/122 patients in the pertuzumab arm (72.1%) and 86/120 patients in the placebo arm (71.7%) during the chemotherapy treatment period, compared with 15/98 patients in the pertuzumab arm (15.3%) and 15/86 patients in the placebo arm (17.4%) following discontinuation or completion of docetaxel.