Pertuzumab in metastatic breast cancer: unanswered questions

Recently, Baselga and colleagues published in New England Journal of Medicine the analyses of the Clinical Evaluation of Pertuzumab and Trastuzumab Study (CLEOPATRA) (1). CLEOPATRA is a phase III trial in 808 patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer receiving first line therapy with docetaxel and trastuzumab with placebo or pertuzumab until disease progression or unacceptable toxicity.