Sentence: A favourable response to chemotherapy can be expected in up to 60 % of patients receiving a combination of streptozocin plus doxorubicin , and in up to 40 % of patients receiving dacarbazine .
Drug combination annotation:
[{'class': 'POS', 'spans': ['streptozocin', 'doxorubicin'], 'is_context_needed': False}]