Sentence: We randomly assigned 808 patients with HER2-positive metastatic breast cancer to receive placebo plus trastuzumab plus docetaxel ( control group ) or pertuzumab plus trastuzumab plus docetaxel ( pertuzumab group ) as first-line treatment until the time of disease progression or the development of toxic effects that could not be effectively managed .
Drug combination annotation:
[{'class': 'POS', 'spans': ['pertuzumab', 'trastuzumab', 'docetaxel'], 'is_context_needed': True}, {'class': 'COMB', 'spans': [0, 1], 'is_context_needed': True}]